:~ 

l 

..i 

• 

REF ID:A63860 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED 

National Security Agency 

Fort George G. Meade, MarylanCI 

THE FRIEDMAN LECTURES 

Excluded From Automatic Regrading; 

DOD DIR 5200.10 Does Not Apply 

OFFICE OF TRAINING SERVICES 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED 

Declassified and approved for release by NSA on 11-19-2013 pursuant to E .0. 1352a 
REF ID:A63860 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED 

NATIONAL SECURITY AGENCY 

SIX LECTURES ON CRYPTOLOGY 

by 

WILLIAM F. FRIEDMAN 

April 1963 

OFFICE OF TRAINING SERVICES 

NATIONAL SECURITY AGENCY 

Fort George G. Meade, Maryland 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED 
REF ID:A63860 

GQN'R:llDl'Tl-4...ls 

FOREWORD 

These six lectures by Mr. William F. Friedman, dean of American cryptologists, were prepared under an NSA contract in order to have the history of cryptology recorded by one who, 

perhaps more than any other in our country, has played a vital role in this :field. It is hoped 

that both new and old employees may be inspired with a feeling of belonging to an ancient 

profession-one that abounds in drama and fascination, and one that has had a profound impact on the turn of events in history. The lectures are published here for the first time in 

one volume. 

Shelby L. Patterson 

Chief, Office of Training Services 

ii 
REF ID:A63860 

COfft'IBKN'ffAL 

CONTENTS 

Page 

LEC~I--------------------------------------------------------------- 1 

Introduction 

LEC'I'UR.E II-------------------------------------------------------------- 15 

The earliest attempts at cryptography, from the invention of the art of writing 

to Bacon's "Bi-literarie" cipher. 

LEC'l'UllE III_____________________________________________________________ 37 

The cryptosystems used by the British Regulars and by the Colonials during the 

period of the American Revolution. This is followed by a brief explanation of the 

cryptanalytic nature of the initial breaks in the solution of the ancient Egyptian 

hieroglyphic writing. 

LECTURE I\7-------------------------------------------------------------- 55 

Cryptology in the Civil War. 

LECTURE V ________ __ __ ___ _____ ____ ______ ____ __ ______ ____ _ _____ _ _ _ ___ __ _ _ _ 89 

Cryptology from the end of the Civil War to the end of World War I. 

LEC'l'UR.E VI------------------------------------------------------------- 131 

Cryptology from the end of World War I to the end of World War II. The emphasis has been placed upon communication security (COMSEC), not only because 

in five prec.eding lectures the emphasis was placed very largely upon communication inteJligence (COMINT), but also because, in the final analysis, COMSEC, 

though not as spectacular as COMINT, is really more vital to national security. 

A.PPENIJI:X: 1-------------------------------------------------------------- 175 

.APPENIJI:X:2______________________________________________________________ 178 

Biographical Sketch_________________________________________________________ 182 

iii 
' 

REF ID:A63860 

Lecture I 

The objective of this series of lectures is to create an awareness of the background, development, and manner of employment of a science that is the basis of a vital, military offensive and 

defensive weapon known as CRYPTOLOGY, a word that comes from the Greek kryptos, meaning 

secret or hidden, plus logos, meaning knowledge or learning. Cryptology will be specifically defined a little later; at the moment, however, I'm sure you know that it has to do with secret 

communications. 

Let me say at the outset of these lectures that I may from time to time touch upon matters 

which are perhaps essentially peripheral or even irrelevant to the main issues, and if a defense 

is needed for such occasional browsing along the byways of the subject, it will be that long 

preoccupation with any field of knowledge begets a curiosity the satisfaction of which is what 

distinguishes the dedicated professional from the person who merely works just to gain a livelihood in whatever field he happens to find himself a job. That's not much fun, I'm afraid. 

By the way, a British writer, James Agate, defines a professional as the man who can do his 

job even when he doesn't feel like doing it; an amateur, as a man who can't do his job even 

when he does feel like doing it. This is pretty tough on the gifted amateur and I for one 

won't go all the way with Agate's definition. There are plenty of instances where gifted 

amateurs have done and discovered things to the chagrin and red-facedness of the professionals. 

Coming back now to the main thoroughfare after the foregoing brief jaunt along a byway, I 

may well begin by telling you that the science of cryptology has not always been regarded as 

a vital military offensive and defensive weapon, or even as a weapon in the first place. Here 

I am reminded of a story in a very old book on cryptography. The story is probably apocryphal, but it's a bit amusing, and I give it for what it's worth. 

It seems that about two thousand years ago there lived a Persian queen named Semiramis, 

who took an active interest in cryptology. She was in some respects an extraordinarily unpleasant woman, and we learn without surprise that she met with an untimely death. She 

left behind her instructions that her earthly remains were to be placed in a golden sarcophagus 

within an imposing mausoleum, on the outside of which, on its front stone wall, there was to 

be graven a message, saying: 

Stay, weary traveller! 

If thou art footsore, hungry, or in need of moneyUnlock the riddle of the cipher graven below, 

And thou wilt be led to riches beyond all dreams of avarice! 

Below this curious inscription was a cryptogram, a jumble of letters without meaning or 

even pronounceability. For several hundred years the possibility of sudden wealth served as 

a lure to many experts who tried very hard to decipher the cryptogram. They were all without success, until one day there appeared on the scene a long-haired, bewhiskered, and bespectacled savant who, after working at the project for a considerable length of time, solved the 

cipher, which gave him detailed instructions for :finding a secret entry into the tomb. When 

he got inside, he found an instruction to open the sarcophagus, but he had to solve several 

more cryptograms the last one of which may have involved :finding the correct combination to 

a 5-tumbler combination lock-who knows? Well, he solved that one too, after a lot of work, 

and this enabled him to open the sarcophagus, inside which he found a box. In the box was 

a message, this time in plain language, and this is what it said: 

1 
CON.FfB:EN'f'IAL 

0, thou vile and insatiable monster! To disturb these poor bones! 

If thou hadst learned something more useful than the art of 

deciphering, 

Thou wouldst not be footsore, hungry, or in need of money! 

I'm frank to confess that many times during my 40-year preoccupation with cryptology, 

and generally near the middle and the end of each month, I felt that good old Queen Semiramis 

knew what she was talking about. However, earning money is only a part of the recompense 

for working in the cryptologic field, and I hope that most of you will find out sooner or later 

what some of these other recompenses are, and what they can mean to you. 

If Queen Semiramis thought there are other things to learn that are more useful than the 

art of deciphering, I suppose we'd have to agree, but we are warranted in saying, at least, 

that there isn't any question about the importance of the role that cryptology plays in modern times: all of us are influenced and affected by it, as I hope to show you in a few minutes. 

I shall begin by reading from a source which you'll all recognize-Time, the issue of 17 

December 1945. I will preface the reading by reminding you that by that date World War 

II was all over - or at least V-E and V-J days had been celebrated some months before. Some 

of you may be old enough to remember very clearly the loud clamor on the part of certain 

vociferous members of Congress, who had for years been insisting upon learning the reasons 

why we had been caught by surprise in such a disastrous defeat as the Japanese had in:flicted 

upon us at Pearl Harbor. This clamor had to be met, for these Congressmen contended that 

the truth could no longer be hushed up or held back because of an alleged continuing need 

for military secrecy, as claimed by the Administration and by many Democratic senators and 

representatives. The war was over - wasn't it? - Republican senators and representatives 

insisted. There had been investigations-a half dozen of them-but all except one were Top 

Secret. The Republicans wanted-and at last they got what they desired-a grand finale 

Joint Congressional Investigation which would all be completely open to the public. No 

more secrets! It was spectacular. Not only did the Congressional Inquiry bring into the 

open every detail and exhibit uncovered by its own lengthy hearings, but it also disclosed to 

America and to the wlwle world everything that had been said and shown at all the previous 

Army and Navy investigations. Most of the information that was thus disclosed had been, 

and much of it still, was Top Secret; yet all of these precious secrets became matters of public 

information as a result of the Congressional Investigation. 

There came a day in the Congressional Hearings when the Chief of Staff of the United States 

Army at the time of the Pearl Harbor Attack, 5-star General George C. Marshall, was called 

to the witness stand. He testified for several long, long days, eight of them in all. Toward 

the end of the second day of his ordeal he was questioned about a letter it had been rumored 

he'd written to Governor Dewey in the Autumn of 1944, during the Presidential Campaign. 

The letter was about codes. With frozen face, General Marshall balked at disclosing the 

whole letter. He pleaded most earnestly with the Committee not to force him to disclose 

certain of its contents, but to no avail. He had to bow to the will of the majority of the Committee. I shall now read from Time a bit of information which may be new to many of my 

listeners, especially to those who were too young in December 1945 to be delving into periodical 

literature or to be reading any pages of the daily newspaper other than those on which the 

comics appear. 

Said Time, and I quote: 

"'U.S. citizens discovered last week that perhaps their most potent secret weapon of World 

War II was not radar, not the VT fuse, not the atom bomb, but a harmless little machine which 

cryptographers had painstakingly constructed in a hidden room in Washington. With this 

machine, built after years of trial and error, of inference and deduction, cryptographers had 

duplicated the decoding devices used in Tokyo. Testimony before the Pearl Harbor Committee 

had already shown that the machine, known as 'Magic', was in use long before December 7, 1941, 

CQNFIBHN'flAL 2 

• 
REF ID:A63860 

and had given ample warning of the Jap's sneak attack, if only U.S. brass hats had been smart 

enough to realize it. Now, General Marshall continued the story of 'Magic's' magic: 

1. 'It had enabled a relatively small U.S. Force to intercept a Jap invasion fleet, win a decisive victory in the Battle of the Coral Sea, thus saving Australia and New Zealand. 

2. 'It had directed U.S. submarines unerringly to the sea lanes where Japanese convoys would 

be passing. 

3. 'It had given the U.S. full advance information on the size of the Jap forces advancing on 

Midway, enabled our Navy to concentrate ships which otherwise might have been 3,000 miles 

away, thus set up an ambush which proved to be the turning-point victory of the Pacific war. 

4. 'By decoding messages from Japan's Ambassador Oshima in Berlin, often reporting interviews with Hitler, it had given our forces invaluable information on German war plans.' " 

Time goes on to give more details of that story, to which I may later return but I can't leave 

this citation of what cryptology did toward our winning of World War II without telling you 

that the account given by Time of the achievements of Magic makes it appear that all the 

secret intelligence gained from our reading Japanese messages was obtained by using that 

"harmless little machine" which Time said was used in Tokyo by the Japanese Forei~n Office. 

I must correct that error by explaining first that Magic was not the name of the machine but 

a term used to describe the intelligence material to which the machine, among other sources, 

contributes and then by telling you that the secret information we obtained that way had 

little to do with those portions of the Magic material which enabled our Navy to win such 

spectacular battles as those of the Coral Sea and Midway, and to waylay Japanese convoys. 

The naval parts of Magic were nearly all obtained from Japanese naval messages by our own 

very ingenious U.S. Navy cryptanalysts. At that time, I may tell those of you who are new, 

the Army and Navy had separate but cooperating cryptologic agencies and activities; the 

United States Air Force was not yet in existence as an autonomous and separate component 

of the Armed Forces, and work on Japanese, German, and Italian Air Force communications 

was done by Army cryptanalysts, admirably assisted by personnel of what was then known as 

the Army Air Corps. 

It is hardly necessary to tell you how carefully the Magic of World War II was guarded before, during, and after the war until the Congressional Inquiry brought most of it out in the 

open. Some remaining parts of it are still very carefully guarded. Even the fact of the existence of Magic was known to only a very few persons at the time of Pearl Harbor - and 

that is an important element in any attempt to explain why we were caught by surprise by 

the Japanese at Pearl Harbor in a devastating attack that crippled our Navy for many months. 

Let me read a bit from page 261 of the Report of the Majority of the Joint Congressional 

Investigation of the attack: 

"The Magu: intelligence was pre-eminently important and the necessity for keeping it confidential cannot be overestimated. However, so closely held and top secret was this intelligence 

that it appears that the fact that the Japanese codes had been broken was regarded as of more 

importance than the information obtained from decoded traffic.'' 

Time says, in connection with this phase of the story of Magic during World War II: 

"So priceless a possession was Magu: that the U.S. high command lived in constant fear that 

the Japs would discover the secret, change their code machinery, force U.S. cryptographers to 

start all over again." 

Now I don't want to overemphasize the importance of communication intelligence in 

World War II, but I think it warranted to read a bit more of what is said about its importance 

in the Report of the Majority. The following is from p. 232: 

" ... all witnesses familiar with Magu: material throughout the war have testified that it contributed enormously to the defeat of the enemy, greatly shortened the war, and saved many 

thousands of lives." 

General Chamberlin, who was General MacArthur's operations officer, or G-3, throughout 

the war in the Pacific, has written: "The information G-2, that is, the intelligence staff, gave 

3 OONFIBEN'l'IA:l 
REF ID:A63860 GO~DE'H'l'l! .. L 

me in the Pacific Theater alone saved us many thousands of lives and shortened the war by 

no less than two years." We can't put a dollars-and-cents value on what our possession of 

COMINT meant in the way of saving lives; but we can make a dollars-and-cents estimate of 

what communications intelligence meant by shortening the war by two years, and the result 

of that estimate is that it appears that $1.00 spent for that sort of intelligence was worth $1,000 

spent for other military activities and materials. 

In short, when our commanders had that kind of intelligence in World War II they were 

able to put what small forces they had at the right place, at the right time. But when they 

didn't have it-and this happened, too-their forces often took a beating. Later on we'll 

note instances of each type. 

I hope I've not tried your patience by such a lengthy preface to the real substance of this 

series of lectures; let's get down to brass tacks. For those of you who come to the subject of 

cryptology for the first time, a few definitions will be useful, in order that what I shall be talking about may be understood without question. Agreement on basic terminology is always 

desirable in tackling any new subject. In giving you the definitions there may be a bit of 

repetition because we shall be looking at the same terms from somewhat different angles. 

First, then, what is cryptology? Briefly, we may define it as the doctrine, theory, or branch 

of knowledge which treats of hidden, disguised, or secret communications. You won't find 

the word in a small dictionary. Even Webster's Unabridged defines it merely as "secret or 

enigmatical language"; and in its "Addenda Section," which presumably contains new or 

recently coined words, it is defined merely as "the study of cryptography." Neither of these 

definitions is broad or specific enough for those who are going to delve somewhat deeply into 

this science. 

Cryptology has two main branches: the first is cryptography, or, very briefly, the science of 

preparing secret communications; and the second is cryptanalysis, or the science of solving 

secret communications. Let's take up cryptography first, because as a procedure it logically 

precedes cryptanalysis: before solving anything there must be something to solve. 

c~ 

130 13042 13401 85C1 115 3518 418 17214 8491 11310 

1814"1 18222 2UH!O 1024? US18 2387"1 13805 HIC. HUD 

nec92 59C5 11311 1C392 10:571- 0302 21200 5101 He9S 

~3571 1?504 112•9 1827! 18101 0317 0228 1789' '473 

U214 22200 1945~ 21589 8'11193 5'\89 1~18 ll9M 12137 

1333 4725 4458 59C& 17188 158&1 4458 17149 1'471 8708 

138&' 12224 8929 14991 7382 15857 !7893 14111 SM77 

23r•c 

C!~2· 

!0439 

211CO 

218• 

51'4 

10482 

1"5f:!' 

... :st1e 

2:11i"i';2 

18HO 

5:?"5 

14814 

&1272 

53?8 

2831 

1175511 

'! .. e':'-: 

.,,,, 

22()90 

222l'C 

185~" 

4178 

934! 

'7'382 

17920 

35119 

SS?t' 5454 11!10:! 

231!38 18228 fl"/19 

21804 479'1 IJf,t)':" 

5905 1334'1 20fl!O 

5221"2 U'IC 2204CJ 

11992 878• 7!32 

9559 2241'' 15874 

98C92 J!127 134811 

223'7 17141 11~84 

38'1C 

HPNSIOPIT. 

tli217 22801 17118 

H331 1&021 UM& 

aztac 211811& '377 

391180 IS7H IOllll7 

13339 ll.111& 12111& 

7357 111118 112181 u- 18502 18IOIJ 1111&' 

9311() 9280 

,_ Ul18 

7887 779& 

--

Figure 1.-The Zimmerman Telegram. 

4 
.. 

REF ID:A63860 

09NFIBF1Nf"IAL 

Cryptography is that branch of cryptology which deals with the various means, methods, 

devices, and machines for converting messages in ordinary, or what we call plain language, 

into secret language, or what we call cryptograms. Here's a picture of one of the most famous cryptograms in history. It was the solution of this cryptogram which resulted in bringing America into World War I on the side of the Allies on 6 April 1917, just about six weeks 

after it was solved. I'll ten you about it later in this series. 

Cryptography also includes the business of reconverting the cryptograms into their original 

plain-language form, by a direct reversal of the steps followed in the original transformation . 

This implies that the persons involved in both of these bits of business, those at the enciphering and sending end, and those at the receiving and deciphering end, have an understanding 

as to what procedures, devices, and so on, will be used and exactly how-down to the very 

last detail. The what and the how of the business constitutes what is generally referred to as 

the key. The key may consist of a set of rules, alphabets, procedures, and so on; it may also 

consist of an ordinary book which is used as a source of keys; or it may be a specialized book, 

called a code book. Th.at cryptogram I just showed you was made by using a book-a German 

codebook. 

To encrypt, is to convert or transform a plaintext message into a cryptogram by following 

certain rules, steps, or processes constituting the key or keys and agreed upon in advance by 

the correspondents, or furnished them by higher authority. 

To decrypt is to reconvert or to transform a cryptogram into the original equivalent plaintext message by a direct reversal of the encrypting process that is, by applying to the cryptogram the key or keys, usually in a reverse order, employed in producing it. 

A person who encrypts and decrypts messages by having in his possession the necessary 

keys, is called a cryptographer, or a cryptographic clerk. 

Encrypting and decrypting are accomplished by means collectively designated as codes and 

ciphers. Such means are used for either or both of two purposes: (1) secrecy, and (2) economy. 

Secrecy usually is far more important in diplomatic and military cryptography than economy, 

but it is possible to combine secrecy and economy in a single system. Persons technically unacquainted with cryptology often talk about "cipher codes," a term which I suppose came into 

use to differentiate the term "code" as used in cryptology from the same term as used in other 

connotations, as, for example, the Napoleonic Code, a traffic code, a building code, a code of 

ethics, and so on. Now, in cryptology, there is no such thing as a "cipher code." There are 

codes and there are ciphers, and we might as well learn right off the differences between them, 

so that we get them straightened out in our minds before proceeding further. 

In ciphers, or in cipher systems, cryptograms are produced by applying the cryptographic 

treatment to individual letters of the plaintex.t messages, whereas, in codes, or in code systems, 

cryptograms are produced by applying the cryptographic treatment generally to entire words, 

phrases, and sentences of the plaintex.t messages. More specialized meanings of the terms will 

be explained in detail later, but in a moment I'll show you an example of a cryptogram in 

cipher and one in code. 

A cryptogram produced by means of a cipher system is said to be in cipher and is called a 

cipher message, or sometimes, simply a cipher. The act or operation of encrypting a cipher 

message is called enciphering, and the enciphered version of the plain text, as well as the act 

or process itself, is often referred to as the encipherment. A cryptographic clerk who performs 

the process serves as an encipherer. The corresponding terms applicable to decrypting cipher 

messages are deciphering, decipherment, decipherer. 

A cryptogram produced by means of a code system is said to be in code, and is called a code 

message. The text of the cryptogram is referred to as code text. This act or operation of encrypting is called encoding, and the encoded version of the plain text, as well as the act or 

process itself, is referred to as the encodement. The clerk who performs the process serves as 

an encoder. The corresponding terms applicable to the decrypting of code messages are decod5 C6NPffll~NTIAL 
REF ID:A63860 

OONFIBBN'i?IAL 

ing, decodement, and decoder. A clerk who encodes and decodes messages by having in his possession the pertinent code books is called a code clerk. 

Technically, there are only two distinctly different types of treatment which may be applied 

to written plain text to convert it into a cipher, yielding two different classes of ciphers. In 

the first, called transposition, the letters of the plain text retain their original identities and 

merely undergo some change in the relative positions, with the result that the original text 

becomes unintelligible. Here's an authentic example of a transposition cipher; I call it authentic because it was sent to President Roosevelt and the Secret Service asked me to decipher 

it. Imagine my chagrin when I had to report that it says "Did you ever bite a lemon?" In 

the second, called substitution, the letters of the plain text retain their original relative positions, 

but are replaced by other letters with different sound values, or by symbols of some sort, so 

that the original text becomes unintelligible. 

Figure 2. 

Nobody will quarrel with you very hard if you wish to say that a code system is nothing 

but a specialized form of substitution; but it's best to use the word "code" when a code book 

is involved, and to use "substitution cipher" when a literal system of substitution is used. 

It is possible to encrypt a message by a substitution method and then to apply a transposition method to the substitution text, or vice versa. Combined transposition-substitution 

ciphers do not form a third class of ciphers; they are only occasionally encountered in military 

cryptography. Applying a cipher to code groups is a very frequently used procedure and 

we'll see cases of that too. 

Now for an example of a cryptogram in code. In Fig. 3 is a plaintext message in the handwriting of President Wilson to his special emissary in London, Colonel House. Contained in 

Fig. 4 is the cryptogram after the plain text was encoded by Mrs. Wilson. The President 

himself then typed out the final message on his own typewriter, for transmission by the 

OONFIBIBN'FIAL 6 
- .. 

REF ID:A63860 

OONFiffiflN'f'IAL 

Department of State. It would appear that President Wilson lacked confidence in the 

security of the Department of State's methods-and maybe with good reason, as may be seen 

in the following extract from a letter dated 14 September 1914 from the President to Ambassador Page in London: "We have for some time been trying to trace the leaks, for they have 

occurred frequently, and we are now convinced that our code is in possession of persons at 

int.ermediary points. We are going to take thoroughgoing measures." Perhaps one of the 

measures was that the President got himself a code of his own. I must follow this up some 

day. 

Figure 3. 

3?,oezf-333'!1 -3J~Oo-

~7~ o (j, - 3:1,0'fD _!J2,Uf.-!l2.'ja.7 

)'2.J.3t.- ZocA1tl(-t:..ro1~-.tro01- -7.a(;Jo 

4o!' Sf~- - '6 '' / .3 -4-~o4·Y-~.J33' -~1~?~ 

'f{, 3 /;a. -2a. ti¥.3 -(A-o'a ~!1.,//-/lYo.e 

"'' !:,-, -z"',...t~o _3,r1:a-''ffJ"ll-J/'/733 

S'gJt~~-174 i8- /f,f3/-!,"'l'i6·7-317s·~ 

,l,f/.!;6·6-/ J$-0:3-l,1111·-4~120 -¥4~30 

2~fl{,D,-11' 'iJC.-4J/2.'l-'lll~fl -711/0lf 

l/lfV~!iFigure 4. 

A cipher device is a relatively simple mechanical contrivance for encipherment and decipherment, usually hand-operated or manipulated by the fingers, as, for example, a device with concentric rings of alphabets, manually powered. In Fig. 5 is an example-a cipher device with 

such rings. I'll tell you about it later. A cipher machine is a relatively complex apparatus 

or mechanism for encipherment and decipherment, usually equipped with a typewriter keyboard and generally requiring an external power source. Modem cryptology, following the 

trend in mechanization and automation in other :fields, now deals largely with cipher machines, 

some highly complicated. Fig. 6 shows an example of a modern cipher machine with keyboard and printing mechanism. ___ ..._ 

One of the expressions whicCunffi?;;J>laym.en use, but which you must never use, is "the 

Germ.an code," or "the Japanese code," or "the Navy cipher," and the like. When you hear 

this sort of expression you may put the speaker down at once as a novice. There are literally 

hundreds of different codes and ciphers in simultaneous use by every large and important 

government or service, each suited to a special purpose; or where there is a multiplicity of systems of the same general nature, the object ·is to prevent a great deal of traffic being encrypted 

in the same key, thus overloading the system and making it vulnerable to attack by methods 

and procedures to be mentioned in broad terms in a few moments. 

7 GO:NFil>E:N'l'I:! ... J.. 
REF ID:A63860 

CONPIBEN'f'fAL 

Figure 5. 

Figure 6.-TSEC/KL--7 Cipher Machine (U.S.). 

OONFIBEN'flAL 8 
REF ID:A63860 

CON.FfBEN'fiAL 

The need for secrecy in the conduct of important affairs has been recognized from time immemorial. In the case of diplomacy and organized warfare this need is especially important 

in regard to communications. However, when such communications are transmitted by electrical means, they can be heard or, as we say, intercepted, and copied by unauthorized persons, 

usually referred to collectively as the enemy. The protection resulting from all measures designed to deny to the enemy information of value which may be derived from the interception 

and study of such communications is called communication security, or, for short, COMSEC. 

In theory, any cryptosystem except one, to be discussed in due time, can be attacked and 

"broken," i.e., solved, if enough time, labor, and skill are devoted to it, and if the volume of 

traffic in that system is large enough. This can be done even if the general system and the 

specific key are unknown at the start. You will remember that I prefaced my statement any 

cryptosystem can be solved by saying "in theory," because in military operations theoretical 

rules usually give way to practical considerations. 

That branch of cryptology which deals with the principles, methods, and means employed 

in the solution or analysis of cryptosystems is called cryptanalytics. The steps and operations 

performed in applying the principles of cryptanalytics constitute cryptanalysis. To cryptanalyze a cryptogram is to solve it by cryptanalysis. A person skilled in the art of cryptanalysis 

is called a cryptanalyst, and a clerk who assists in such work is called a cryptanalytic clerk. 

Information derived from the organized interception, study, and analysis of the enemy's 

communications is called communication intelligence, or, for short, COMINT. Let us take careful note that COMINT and COMSEC deal with communications. Although no phenomenon is 

more familiar to us than that of communication, the fact of the matter is that this magic word 

means many things to many people. A definition of communication that is broad enough 

for our purposes would be that communication deals with intelligent messages exchanged between intelligent beings. This implies that human beings and human operators are involved 

in the preparation, encryption, transmission, reception, decryption, and recording of messages 

which at some stage or stages are in written form and in some stage or stages are in electrical 

form as signals of one sort or another. But in recent years there have come into prominence 

and importance electrical signals which are not of the sort I've just indicated. They do not 

carry "messages" in the usual sense of the word; they do not convey from one human being 

to another an intelligible sequence of words and an intelligible sense. I refer here to electrical 

or electronic signals such as are employed in homing or directional beacons, in radar, in telemetering or recording data of an electrical or electronic nature at a distance, and so on. Information obtained from a study of enemy electronic emissions of these sorts is called electronic 

intelligence, or, for short, ELINT. COMINT and ELINT comprise SIGINT, that is, signal intelligence. Cryptology is the science which is concerned with all these branches of secret signalling. 

In this series of lectures we shall be concerned only with COMSEC and COMINT, leaving for 

others and for other times the subject of ELINT. This means that we shall deal with communications or messages. 

Communication may be conducted by any means susceptible of ultimate interpretation by 

one of the five senses, but those most commonly used are seeing and hearing. Aside from the 

use of simple visual and auditory signals for communication over relatively short distances, 

the usual method of communication between or among individuals separted from another by 

relatively long distances involves, at one stage or another, the act of writing or of speaking 

over a telephone. 

Privacy or secrecy in communication by telephone can be obtained by using equipment 

which affects the electrical currents involved in telephony, so that the conversations can be 

understood only by persons provided with suitable equipment properly arranged for the purpose. The same thing is true in the case of facsimile transmission (i.e., the electrical transmission of ordinary writing, pictures, drawings, maps). Even today there are already simple 

forms of enciphered television transmissions. Enciphered facsimile is called cifax; enciphered 

telephony, ciphony; and enciphered television, civision. However, these lectures will not 

9 
REF ID:A63860 

The Yukon Trail THE BLUE 

'.t 

I 

Figure 7. 

10 
REF ID:A63860 C~AL 

deal with these electrically and cryptanalytically more complex forms of cryptology. We 

shall stick to enciphered or encrypted writing-which will be hard enough for most of us. 

Writing may be either visible or invisible. In the former, the characters are inscribed with 

ordinary writing materials and can be seen with the naked eye; in the latter, the characters are 

inscribed by means or methods which make the writing invisible to the naked eye. Invisible 

writing can be prepared with C'.ertain chemicals called sympathetic or secret inks, and in order 

to "develop" such writing, that is, make it visible, special processes must usually be applied. 

Shown in Fig. 7 is an interesting example-the developed secret-ink message that figured 

in an $80,000,000 suit won by two American firms against the German Government after 

World War I sabotage was proved. There are also methods of producing writing which is invisible to the naked eye because the characters are of microscopic size, thus requiring special 

microscopic and photographic apparatus to enlarge such writing enough to make it visible to 

the naked eye. Here's an example-a code message in a space not much larger than the head 

........ ').~ \...4.,..t ......... .._.,,._ 

....... ._""' ... ,.. ... ,...tll' ........ .!'&'M:I 

......... ....,,. ...... ,., ............. , ... .,'Ill 

J...-•IR.f-Cfllf .... .,.~ .. ,...,,,,...._ ;-....---~ ............. __ 

.......... ... .,_ 

_._,,.,,,,, ... .. l«"'.,'I~ __ ""'"""" __ ._ ... .. _. ......... 111111_&.. .. 

.... ..,_ ... , ... ,,._..,.,_,...,._. ............... 

-~,. 

,..,._,.. ............... .... "= -

.. 

....... 

"""---

_ -__ ..... ...... 

~ ·-~ 

... _._ ....... _ #lllo- .. - ..... ai ~ 

___ ,.. __ ,, ..... ----=·-- - _,:,, ....... ···--"""--.-... .,, ---·----~-·- _. __ _ _ .. ..,....,111111••-••- •••IP '"-·• 

'•r.a..,,,,..""' ~ ..... ,__ ... ..,.,...,...._.....,.. •~""' - - --__ .lo _ ., ............................ Mt-•'t' ..... .. r .,..r--..,,.,.,.. __ ,,__,....~,.,_,.. 

I ........ .,. .... --.,-... ..if-·,. .. I ~ ...................... _ ... ~_W"ll'J. 

-..rW"•·--... ~"'-*' ., ... , ... ...... ., .. .,. .... ,.. .... _ ... ,..., .. , ... -..... .,.,.. ............... ..-... .... ,,,. ...... --........... _yt_ .... __ ..,. ... ,.,, I...,.,. ......... .., ... ,... .. ,..,..,.,. .. .., I ...,.,.... ............ .,..,...._ .... ftll .... .., 

..... llftild..:A,.... •• ,... ......... _ ... _ 

,,.,,..,,,,.,, ......... ""1 ... .,.,.i:.io., ..... _ = &...n.f....,..,,.-. ...... _. • .,. .. ............ .,.,,.nj!r"'•A'l;'lllfll•., 

_ ..... 181--'• .. ., ................ .,.. .... . ..,._,. ... _...,_ .... _ ...... _ ~ .... 

,e:::: :i-.: :~: :,:::::.::: ~ ...... ~ ... -,. _.., ___ ~_,_,.. 

I""""'-_. .... w .... 

.............. _ .. ...,.,.. _____ --lo"' ... _ . .... ,.. ... .............. - ........... -11.1 

-llfl-.,. .... .,,---.--•'-....... 1 ,...,._._..?".,.!.'1.,....,..,..._r.!.Lr-~ """"".-.,,,,..., .... _="".,_ .. ..., ~--............ ,. ... ,_,., __ ,.. .... -................. .,. .... .,--i """ ... .,. ___ ........ .,. Jl'j_._.,., ___ _ ,,, ...... -w ..... --.... - ...... .... .,. __ .It """'"'1=--... - ... __ _ 

- ................... - ....... ,..+-:ill' 1uii--""r11J1-... ..,..,,.. • ..,. __ _..._ ... ,._,.,_:. ............... __ __ ... te-L ..,_ .... 

... -..,. ... 

__ --,.. ......... ____ _ .. _ _ 

• ~-~ 1111' .... -..., ........ _,,,.. __ 

.. """""" -·-.. --.......... .. __ .,.._,.._ ,._,.,, ___ 

.... _,_, _ 'i·~I',. ....... _ .... *,..~ .. .,. ... ~-....... -"" ... ___ . ._...,....._ ·---... .., ...... idf-,-~-- ... ,....,c.""',,....... ___ .. _.,.. • .,. ----·-....... -,,. ... .., ....... .,, orJ"''i'I..,~--..,..,., ..... ......... ..... Mtlllf"Mt•• _,._ .... .,.-f ... "'t .. , ....... -~ .. _,,, .. ,... ...... ,,...,.. 

_ ...... _ ~-- -__ ....... ,.,._ ....... _. ___ ...... __ _..,,.....-'-.,- _ ... ..,...,._..,. .. __ .. .., .... .., ....... ... ,,._lo...__ ........ ,-............ .-... .-i>l'll'•'---111-....- ...... _.., ... _,., ...... ....... .. .., ____ ,,., -________ ..,_._,,_.,.. ...... 

......... ,.. ........ _ ... _ .... ~-·--­ -""' _ _._ll'i_"" __ ""l.,....,_ ... __ ....... lo I ..... ,.,,,,...tflo_.,,._,.., .... _ .... _ ...... _ .... ..,_,,,,.,.._ . .. _ or ... ~---=-1 ......... ,sr .... _.,. 

---... -=r. ... _.,__ ........ .,., ..... 11..., ... J/CI,. ...... ,,, ____ _ 

--.. --... - ... ,...1 ... _ .. _ ..... . --""""""' , .. ,...._ -~r6~ ........... ~ .. 

...... -...,.., .... 'o(..,._ ...... _,.,,., - ............ .IV""" .. ,,..,, __ .,~ ...... 

·-_..,...,..,,.,...,_ .. MIM--• _ ... ...,.11 .. .,,.-..... - ... ,.. _....,. __ 

...11111111 .... •"---i"'i'"';fl?" .. II.,. tr•.,. .. ,.,,. ........ .. "''""'.lio;"" ...... ,.., ..... ...,_ , ............. ,,,._ .. ___ .. __ ,'-" ,_,,.. __ .. r, _,,..,,_ ...... ""'- _ .... ,,. 

;.;::,:::;;::;.:.~':."Z;:-: 

.,. _ .. ,...llrt..,_,..~1....,.--...,._ir. 

~~·•F-->-!"'l'""ll''f!"'rl'I' 

....... _.,,.,..., .......... ,,.... ... ~~"":'-

.... .,.,.,..,.llf ... ""'tT--h-*'1111• .. y, tlilf-:1 .. ,,,........,_ ...... _ ....... _.,. 

1117t-'_ ........ _ ... .,,.,....,,.-...... . ..,,._.'P" __ ...,..,._ .... .,. ___ ., .., .• ttr,'., ........ ,....f..,.W. ... ,,.ip 

......... .,.. .... ,,.,, .......... ..,."i" ..... . .... ,,,, •• ,...._,,,, ___ -....;.._ .... iw 

-....... ..._ __ .. _ ....... , ... ,,.,, ... .,,_... .. ... -_______ .. --.. :.t .. tr- • .,,...,,,.,.,_,..,...,. 

_ ..,. __ ... .; ......... -... -----..... ............ ,....,.-.. ... ____ _ "" ... ,,.. __ ..,, - --·-... ,.._ y 

....... - .... """'"•:Ill.,.-_ .. _ _ _..,,... 1 n•Y -• • ----.#1: __ ""..,. ... -... .-............. --- .. ,,_ .. ,.,,. .. ___ ...... ,.,. ... .,, ... .--... _ .... _ .... - ....... ~ .... "="" .... ..... - ... _. ... ___ ..,_ .. -;tM- ........ ., ......... oe.. ........ __ _ 

.,.,..-'-',...,..Ml'lill_M,....J=m1-1w-

__ •'J'o--•--- ........... ,;., .. __ ... -,.,.,. .. .... ---- ..,._~ 

-=--. .,.,...,.,.,_..,._r... ___ .._. ·--" ...... -............... ..,, .... 1:. .......... .,.-.. ... :.rs•W.lf_,_11';._.lfl ------·--------w. ... ......... .. · .. ----.c.~ ..... ... _ ..... "_..,. .... .w: ... -.-; .. .. .., ... 

~- .... ..,-... --... ~-......... ..,. ,, __ ... .:r :<1;1 .. .,,. ............ - ... 

.. .c'O ___ ,,,_...,_...,...,~-,..,_ -... .,. ........ ,, .. ___ ..... ,.. .. _ __ _. ..... _..,-..... -:«.-· ...... .. :111" .... 1111Lo.-................... _ 

:.. ....... _ ............. .., ...... ___ , .. ..... ...: .... - ........ w ..... 

-· --.. ... -,.,,. .... ...: ........ "", ...... ..., .. ~--~ ........ --........ .... 

- ... 

_ .........

- .. Ill,. .. 

..... ----~·--- &o. _ ....... _ ..... 

.. _ .... _ - .... ---•-.ii,.,. 

Figure 8. 

11 OONPIBBN'ff AL 
REF ID:A63860 

CONll'IDEN'f'IkL 

of a pin. A simple definition of secret writing would be to say that it comprises invisible writing 

and unintelligible visible writing. 

There is one additional piece of basic information which it is wise to call to your attention 

before we proceed much further, and I'll begin by stating that the greatest and the most powerful instrument or weapon ever forged and improved by man in his long struggle for emancipation from utter dependence upon his own environment is the weapon of literacy-a mastery of 

reading and writing; and the most important invention, the one that made the weapon of literacy practical, was the invention of the alphabet. It is therefore a rather striking anomaly 

that we should now come to the study of another weapon-a counter-weapon to the weapon of 

literacy-the weapon of secrecy, the basic intent of which is to thwart the weapon that man 

struggled so long to forge. Secrecy is applied to make writing more difficult and the reading of 

the writing very difficult, if not impossible. 

Perhaps this is a good place to do a bit of theorizing about this matter of secrecy and what 

it implies. 

Every person who enciphers a piece of writing, a message, or a text of any kind, for the purpose of hiding something or keeping something secret, does so with the idea that some other 

person, removed from him in distance, or time, or both, is intended to decipher the writing or 

message and thus uncover the secret which was so hidden. A person may possess a certain 

piece of knowledge which he does not wish to forget, hut which he is nevertheless unwilling to 

commit to open writing, and therefore he may jot it down in cryptic form for himself to decipher later, when or if the information is needed. The most widely known example of such a 

cryptogram is found in Edgar Allan Poe's romantic tale The Gold Bug. That sort of usage of 

cryptography, however, is unusual. There are also examples of the use of cipher writing to 

establish priority of discovery, as did the astronomers Galileo and Huygens. I suppose I 

should at least mention another sort of cryptic writing famous in literary history, the diaries 

of persons such as Samuel Pepys and William Byrd. These are commonly regarded as being 

"in cipher," but they were actually written in a more-or-less private shorthand and can easily 

be read without the help of cryptanalysis. In Fig. 9 is shown a page of Pepys' diary. 

Now there can be no logical reason, point, or purpose in taking the time and trouble to encipher anything unless it is expected that some other person is to decipher the cipher some 

time in the future. This means that there must exist some very direct, clear-cut and unambiguous relationship between the enciphering and deciphering operations. Just what such a 

relationship involves will be dealt with later, but at this moment all that it is necessary to say 

is that in enciphering there must be rules that govern or control the operations, that these 

rules must admit of no uncertainty or ambiguity, and that they must be susceptible of being 

applied with undeviating- precision, since otherwise it will be difficult or perhaps impossible for 

the decipherer to obtain the correct answer when he reverses the processes or steps followed in 

the encipherment. This may be a good place to point out that a valid or authentic cryptanalytic solution cannot be considered as being merely what the cryptanalyst thinks or says he 

thinks the cryptogram means, nor does the solution represent an opinion of the cryptanalyst. 

Solutions are valid only insofar as they are objective and susceptible of demonstration or proof 

employing scientifically acceptable methods or procedures. It should hardly be necessary to 

indicate that the validity of the results achieved by cryptanalytic studies of authentic cryptograms rests upon the same sure and well established scientific foundations, and is reached by the 

same sort of logic as are the discoveries, results, or "answers" achieved by any other scientific 

studies, namely: observation, hypothesis, deduction, induction, and confirmatory experiment. 

Implied in what I have just said is the tacitly understood and now rarely explicitly stated assumption that two or more, equally competent and, if necessary, specially qualified investigators, each working independently upon the same material, will achieve identical or practically 

identical results. 

Cryptology is usually and properly considered to be a branch of mathematics, although 

Francis Bacon considered it also a branch of grammar and what we now call linguistics. MathCQNFIBBN'f'fAL 12 
REF ID:A63860 GON.F'IBB~1?:FIAL 

) /\ f- J ~""'~ J 'I ,I , 

~~~. ~~ ... -......-• = ~'.!. , , 

~· J 

J , 

., (, .. .;-

, I '. 't; '- - J ..f ..,, ,, " 

_.,..., ·- , __ •( 

1 ,: I> .,v ... f ~ ,..., .~ s ',. ....._ ~'1 t ,:-

, t .. !• .; .. , ... i"I 

.. """""'· - I r ~"J"i=··--

L' ,.,,,. ,.... '1 ·t J 

..... l"] , 

I f. /-C 

-=:z=_·:.-t , . '·1 ,.- J 1

W£13'_!....! f __ 1 

.. 

..- 11:.? .... fl- , 

----;::} __ ~_- r1 ). I 

., --- -':'"..:::ICIZZ..- ------ - -

= 

: ' 

(1 

.. 

.. 

..--

•. 

I 

' 

J- , ,~ 

I ., ,. ... , :-7. ! -· , , ... ,/ ,' ~ 

j~ ,.. <-- ....... , 

5 . .J •. I 

' .. .,...(.. 'J, 1.1 / ,.. "J .. A 

I ,.- J. 

r. ,, ..,. 

,,. .. 

') 

J 

1-- . 

J- .. 

' - f -~ 

.f 

.. .. ? 7-'' _.,, 

I 

,. 'f ,,.,, ,,uJ,., ,..,..,, l·, 

I "'1Y .J IV 

.., ,.. 

... .1.., -r 

,, ' 

,? ~ r A 

JJ..kr '1' ,-,("'; .. v ! ., , 

J Jiu~;' , .. 

, ..... , - r 

Figure 9. 

13 

:...- , 

r 

,, 

v 

, 

v • 

(,.. 

....., .. , ;' ' 

-( 

:-. 

-

... ' ~r - r 

, 

v' ' I L"' C 

\ I ,_ "'l. I 

/ i. /",,... ,') 

' 2 ' 'u 

,,...; 

t' ' 

J 

,.. " '"" 

... .. , 

CC»WIBEN'l'l2\L 
REF ID:A63860 

CONFIDENTIAL 

ematical and statistical considerations play an ever-increasing and prominent role in practical 

cryptology, but don't let my statement of this point frighten those of you who have not had 

much formal instruction in these subjects. We have excellent cryptologist.s who have never 

studied more than arithmetic, and some of our best ones would hide if you were to go searching 

for mathematicians around here. What is needed is the ability to reason logically, as the 

mathematician sometimes does, and this ability is found in the most curious sorts of persons 

and places. So those of you who are frightened by the words mathematics and statistics take 

heart-you're not nearly so badly off as you may fear. 

But now to return to the main theme, the place mathematics occupies in cryptology, let me 

say that just as the solution of mathematical problems leaves no room for the exercise of divination or other mysterious mental or psychic powers, so a valid solution to a cryptogram must 

leave no room for the exercise of such powers. In cryptologic science there is one and only 

one valid solution to a cryptogram, just as there is but one correct solution or "solution set" 

to any problem in mathematics. But perhaps I've already dwelt on this point too long; in any 

case, we'll come back to it later, when we come to look at certain types of what we may call 

pseudo-ciphers. 

In the next lecture I'm going to give you a brief glimpse into the background or history of 

cryptology, which makes a long and interesting story that has never been told accurately and 

in detail. The history of communication security, that is, of cryptography, and the history 

of communication intelligence, that is, of cryptanalysis, which are but opposite faces of the 

same coin, deserve detailed treatment, but I am dubious that this sort of history will ever be 

written because of the curtain of secrecy and silence which officially surrounds the whole field 

of cryptology. Authentic information on the background and development of these vital matters having to do with the security of a nation is understandably quite sparse. 

But in the succeeding lectures I'll try my best to give you authentic information, and where 

there's conjecture or doubt I'll so indicate. I must add, however, that in this series I'm going 

to have to omit many highly interesting episodes and bit.s of information, not only because 

these lectures are of low classification, but also because we won't and can't for security considerations, go beyond a certain period in cryptologic history. Nevertheless, I hope that you 

won't be disappointed and that you'll learn certain things of great interest and importance, 

things to remember if you wish to make cryptology your vocation in life. 

CONFIDENTIAL 14 
REF ID:A63860 

Lecture II 

As I said at the close of the preceding lecture, a bit of history is always useful in introducing 

a subject belonging to a special and not too well known field; therefore, I'll proceed with some 

historical information about cryptology, which, as you learned before, comprises two closely 

related sciences, namely, cryptography and cryptanalysis. I will repeat and emphasize that 

they are but opposite faces of the same valuable coin; progress in one inevitably leads to progress in the other, and to be efficient in cryptology you must know something about each of 

them. 

Cryptography and cryptanalysis probably go back to the dawn of the invention and development of the art of writing itself. In fact, there is reason for speculating as to which came :firstthe invention of writing or the invention of cryptography; it's somewhat like the question as to 

which came first-the hen or the egg. It is possible that some phases of cryptography came 

before the art of writing had advanced very far. 

I've mentioned the art of writing. As in the case of other seemingly simple questions, such 

as, "why is grass green?," when we are asked to define writing we can't find a very simple 

answer, just because the answer isn't at all simple. Yet, Breasted, the famous University of 

Chicago historian and Orientalist, once said: "The invention of writing and of a convenient 

system of records on paper has had a greater influence in uplifting the human race than any 

other intellectual achievement in the career of man." There has been, in my humble opinion, 

no greater invention in all history. The invention of writing formed the real beginning of 

civilization. As language distinguishes man from other animals, so writing distinguishes civilized man from barbarian. To put the matter briefly, writing exists only in a civilization and 

a civilization cannot exist without writing. Let me remind you that animals and insects do 

communicate-there's no question about that; but writing is a thing peculiar to and found only 

as a phenomenon in which man and no animal or insect engages, and let's never forget this 

fact. Mankind lived and functioned for an enormous number of centuries before writing was 

discovered and there is no doubt that writing was preceded by articulate speech for eons-but 

civilization began only when men got the idea of and invented the art of writing. So far as 

concerns Western or Occidental civilization, writing is, in essence, a means of representing the 

sounds of what we call speech or spoken language. Other systems of writing were and some 

still are handicapped by trying to represent things and ideas by pictures. I'm being a bit solemn about this great invention because I want to impress upon you what our studies in cryptology are really intended to do, namely, to defeat the basic or intended purpose of that great 

invention: instead of recording things and ideas for the dissemination of knowledge, we want 

and strive our utmost to pervent this aim from being realized, except among our own brethren 

and under cerlain special circumstances, for the purpose of our mutual security, our self-preservation. And that's important. 

Writing is a comparatively new thing in the history of mankind. No complete system of 

writing was used before about 3500 B.C. 

Ordinary writing, the sort of writing you and I use, is perhaps an outgrowth or development 

of picture writing or rebus writing, which I'm sure most of you enjoyed as children. A rebus 

contains features of both ordinary and cryptographic writing; you have to "decrypt" the significance of some of the symbols, combine single letters with syllables, pronounce the word that 

is represented by pictures, and so on. Fig. 10 is an example which I have through the courtesy 

of the Bell Telephone Laboratories. See how much of it you can make out in half a minute. 

15 OONPIBHN'f'IAL 
REF ID:A63860 

CONPIBBN't'IAL 

Good E/;;I: as u lhler ~· ull t1i-.:.~ now 

u I ~ kno~.--t&P every~ pre ;:r:. ~':~ 2 u_aD or 

9-f""2# 2. go tli I~~}; a.II of oppor \14' wliich u J! 

must fe-nd _t~e 4g. S th<i>os df N-~. 1~-<d' ~ 

spacious ~~~!_~have Iii 2 e

0

a.. here thef§sil a~in ~~#/1d./thoo9 whoNterhere 

maY. c Then"~ as t~lliill come 2. B. They c the k~ll of £.fl khey could~ Mjcome, {IJ. they ~-?fe 

kind of m whose~-~ th~gentle~ :1 "frl~ness; who know the =:JI!.. ....!:~ 0£ ib.e of !!J- ~ fri~; who~ J'T new /pe, new !ii'11ge & nu 

ch~a f 2. whom they [!] come n~. 

This~as soon. no dJli.iil[_. ult c) is o[ @?la b~ a magic/>:- a tit1 ~.fl' bard :i £ind,~t 2. ~ 

m-i~ L l! &, never V.-never reach: the ~en f of 

gracious s~. 

Th \diiTfj ./\,. ·th ~ by r _:'Piil e ~} we s~ W'l .mm~ '2 near 1~; 

the .... ir t.11. we i-C)~wave @ !llJ ~I ~i'{l a. t- fr- .'1:.. DNr. ..& hEEE. '~ 4 m h ~ 'I ..,.,,.,,_., ~ w-- t E'J/" !fiJ ~&&-'us 2 t est o ~ t~ 

Iii~~ l;Q. '@1y !fl ueme. g ~- - f<O!>Dd '"'-i 

Figure 10. 

From rebus writing there came in due course alphabetic writing and let me eay right now that 

the invention of the alphabet, which apparently happened only once in the history of mankind, 

in some Middle East Semitic region, in or near the Palestine-Syria area, then spread throughout the whole of the European continent, and finally throughout most of the world, is Western 

man's greatest, most important, and most far-reaching invention because it forms the foundation of practically all our written and printed knowledge, except that in Chinese. The great 

achievement of the invention of the alphabet was certainly not the creation of the signs or 

symbols. It involved two brilliant ideas. The :first was the idea of representing merely the 

sounds of speech by symbols, that is, the idea of what we may call phoneticization; the second 

was the idea of adopting a system in which, roughly speaking, each speech sound is denoted or 

represented by one and only one symbol. Simple as these two ideas seem to us now, the invention was apparently made, as I've said, only once and the inventor or inventors of the 

alphabet deserve to be ranked among the greatest benefactors of mankind. It made possible 

the recording of the memory of mankind in our libraries, and from that single invention have 

come all past and present alphabets. Some of the greatest of men's achievements we are now 

apt to take for granted; we seldom give them any thought. The invention of the art of writing 

and the invention of the alphabet are two such achievements and they are worth pondering 

upon. Where would we be without them? Note that among living languages Chinese pre16 
REF ID:A63860 

sents special problems not only for the cryptologist but also for the Chinese themselves. No 

Sinologist knows all the 80,000 or so Chinese symbols, and it is also far from easy to master 

:riierely the 9,000 or so symbols actually employed by Chinese scholars. How far more simple 

it is to use only 20 to 26 symbols! Being a monosyllabic language, it seems almost hopeless to 

try to write Chinese by the sort of mechanism used in an alphabetic polysyllabic language; 

attempts along these lines have been unsuccessful and the difficulties in memorizing a great 

many Chinese characters account for the fact that even now only about 10% of the Chinese 

people can read or write to any significant degree. The spread of knowledge in China is thereby much hampered. 

We find instances of ciphers in the Bible. In Jeremiah Chapter 25, Verse 26 occurs this 

expression: "And the King of Sheshakh shall drink after them." Also, again in Jeremiah 51: 

41: "How is Sheshakh taken!" Well, for perhaps many years that name "Sheshakh" remained 

Jeremiah 25 : 26 " ••• and the king of Sheshakh shall drink after 

them." 

Jeremiah 51 : 41 . "Ho• is Sheshakh taken! ••• how is Babylon become 

an astonishment among the nations~" 

11 10 g 8 7 6 5 4 3 2 1 

I<tl I TChZVHDGBA 

~ -. ~n" 'i tt'"r ~::i~ 

~ l? '6'1! Jli)? ~¥{~ 12 13 14 15 16 17 18 19 20 21 22 

Sh(e)Sh(a)Kh = BBL= Babel= Babyl.On 

L:= A,l C :.D,4 l:_ = I,10 C::::: = M,40 

Figure 11. 

\=.:. =. Q,100 

E.=Th,400 

a mystery, because no such place was known to geographers or historians. But then it was 

discovered that if you write the twenty-two letters of the Hebrew alphabet in two rows, eleven 

in one row and eleven in the other, as in Fig. 11, you set up a substitution alphabet whereby 

you can replace letters by those standing opposite them. For example, "shin," is represented 

by "beth" or vice versa, so that "Sheshakh" translates "Babel," which is the old name of 

"Babylon." Hebrew then did not have and still doesn't have vowels; they must be supplied. 

This is an example of what is called ATHBASH writing, that is, where Aleph, the first letter is 

replaced by Teth, the last letter; Beth, the second letter, by Shin, the next-to-the-last, etc. 

By sliding the second row of letters one letter each time there are eleven different cipher alphabets available for use. The old Talmudists went in for cryptography to a considerable extent. 

17 
REF ID:A63860 

CQNPIBEN'f'IAL 

Incidentally, in mentioning the Bible, I will add that Daniel, who, after Joseph in Genesis, was 

an early interpreter of dreams and therefore one of the first psychoanalysts, was also the first 

cryptanalyst. I say that he was an early psychoanalyst, because you will remember that he 

interpreted Nebuchadnezzar's dreams. In the Bible's own words, "Nebuchadnezzar dreamed 

dreams, wherewith his spirit was troubled, and sleep brake from him." But, unfortunately, 

when he woke up he just. couldn't remember those t.roublesome dreams. One morning he 

called for his wise men, magicians, astrologers, and Chaldean sorcerers and asked them to interpret the dream he'd had during the preceding night. "Well, now, tell us the dream and 

we'll try to interpret it," they said. To which King Nebuchadnezzar exclaimed, "The thing 

is gone from me. I don't remember it. But it's part of your job to find that out, too, and 

interpret it. And if you can't tell me what the dream was, and interpret it, things will happen 

to you." What the king asked was a pretty stiff assignment, of course, and it's no wonder 

they failed to make good, which irked Nebuchadnezzar no end. Kings had a nasty habit of 

chopping your head off in those days if you failed or made a mistake, just as certain arbitrary 

and cruel despots are apt to do even in modern times for more minor infractions, such as not 

following the Party Line. So in this case it comes as no surprise to learn that Nebuchadnezzar 

passed the word along to destroy all the wise men of Babylon, among whom was one of the 

wise men of Israel, named Daniel. Well, when the King's guard came to fetch him, Daniel 

begged that he be given just a bit more time. Then, by some act of divination,-the Bible 

simply says that the secret was revealed to Daniel in a night vision-Daniel was able to reconstruct the dream and then to interpret it. Daniel's reputation was made. Some years later, 

Nebuchadnezzar's son Belshazzar was giving a feast, and, during the course of the feast, in the 

words of the Bible, "came forth fingers of a man's hand and wrote over against the candlestick 

upon the plaster of the wall." The hand wrote a secret message. You can imagine the spinechilling scene. Belshazzar was very much upset, and just as his father did, he called for his 

wise men, soothsayers, Chaldean sorcerers, magicians and so on, but they couldn't read the 

message. Apparently they couldn't even read the cipher characters! Well, Belshazzar's 

Queen fortunately remembered what that Israelite Daniel had done years before, and she suggested that Daniel be called in as a consultant. Daniel was called in by Belshazzar, and he 

succeeded in doing two things. He succeeded not only in reading the writing on the wall: 

"MENE, MENE, TEKEL, UPHARSIN," but also he was successful in deciphering the meaning of those strange words. His interpretation: "Mene" - "God hath numbered thy kingdom 

and finished it." "Tekel" - "Thou are weighed in the balances and found wanting." "Upharsin" - "Thy kingdom shall be divided and given to the Medes and Persians." Apparently 

the chap who did the handwriting on the wall knew a thing or two about cryptography, because 

he used what we call "variants," or different values, for in one case the last word in the secret 

writing on the wall is "Upharsin" and in the other it is "Peres";' the commentators are a bit 

vague as to why there are these two versions of the word in the Bible. At any rate, Babylon 

was finished, just as the inscription prophesied; it died with Belshazzar. I think this curious 

Biblical case of the use of cryptography is interesting because I don't think anybody has really 

found the true meaning of the sentence in secret writing, or explained why the writing on the 

wall was unintelligible to all of Belshazzar's wise men. 

Probably the earliest reliable information on the use of cryptography in connection with an 

alphabetic language dates from about 900 B.C., Plutarch mentioning that from the time of 

Lycurgus there was in use among the Lacedemonians, or ancient Spartans, a device called the 

scytale. This device, which I'll explain in a moment, was definitely known to have been used 

in the time of Lysander, which would place it about 400 B.C. This is about the time that 

Aeneas Tacticus wrote his large treatise on the defense of fortification, in which there is a chapter devoted specifically to cryptography. In addition to mentioning ways of physically concealing messages, a peculiar sort of cipher disk is described. Also a method of replacing words 

and letters by dots is mentioned. 

Figure 12 is a picture of the scytale, one of the earliest cipher devices history records. The 

scytale was a wooden cylinder of specific dimensions around which they wrapped spirally a 

C<»J.i!IBEN'f'fAL 18 
• 

REF ID:A63860 

piece of parchment or leather; they then wrote the message on the parchment, unwound it, and 

sent it to its destination by a safe courier, who handed it over to the commander for whom it 

was intended and who, having been provided with an identically dimensioned cylinder, would 

wind the strip of leather or parchment around his cylinder and thus bring together properly the 

letters representing the message. This diagram may not be accurate. I don't think anyone 

really underRtands the scheme. The writing was done across the edges of the parchment, according to some accounts, and not between the edges, as shown here. Incidentally, you may 

be interested to learn that the baton which the European field marshal still carries as one of 

the insignia of his high office derives from this very instrument . 

Figure 12. 

We don't know much about the use of cryptography by the Romans, but it is well known 

that Caesar used an obviously simple method; all he did was to replace each letter by the one 

that was fourth from it in the alphabet. For example, A would be represented by D, B by E 

and so on. Augustus Caesar is said to have used the same sort of thing, only even more simple: 

each letter was replaced by the one that followed it in the alphabet. Cicero was one of the 

inventors of what is now called shorthand. He had a slave by the name of Tiro, who wrote 

Cicero's records in what are called Tironian notes. Modern shorthand is a development of 

Tiro's notation system. 

In Fig. 13 we see some cipher alphabets of olden times, alphabets used by certain historical 

figures you'll all remember. The :first cipher alphabet in this :figure was employed by Charlemagne, who reigned from 768 to 814 A.D. The second one was used in England during the reign 

of Alfred the Great, 871 to 899. The third alphabet is called ogam writing and was used in 

ancient Ireland. The alphabets below that were used much later in England: the fourth one 

by Charles the First, in 1646; the :fifth, the so-called "clock cipher," was used by the Marquis 

of Worcester in the 17th Century; :finally, the last one was used by Cardinal Wolsey in about 

1524. 

--

ZI + .JI 11 co Hi p A m ~ .x rn T I!, v A y 1P 7 <r ? fJ 111 tp 

... 6 r " e ./ 9 " I " I "' " " p , r .. t u " 3C r ~ 

J< ~ ~ :p * ~ 1tt g l t :J A '+- ~ 'f (i 5). < "'1 /\ *' ~ :t: 

ii z f .. " lz ,,, 

.~. 1fo 11f11 NI. .9 II§ y ,. ... .. 8 t» Gii DI rd ;::i Z. I II ,.,s•mHA•~~ I II Ill 1111 I II 1111111 11111 11111 :llf e "- =e 

"6 e d e /. .9 Ir • ... I ,,.,.. " " I/ ,. ,, t " w"' y >: 

' , ~ :lo I , / I I I I ' _, I I I 7 ~ '-/ <.7 - ""<;. . - ,.: . " 6 " d e .f 9 • k i m "' 0 p " ,. <I t ... ..- "' y z 

G0©080~QG0©080QQG0©000QQ 

.Jt..,~-.,,,.J.,.l/.,t'lllNl"'?~/w-:1~"-"'~-"'..M.•... .... .... ~d .JJ-,.,.,r11,.r,,,.,,_,,1, E.,..._,,;t1,,,.""""'-1..1i1~'" +"6•i 11.-~-~ 

le ;;""°5)11 ~I? J--:-~.-;!'_,..,A -,_,..,.,,.~.,.,..,=ti #-J~ rr-:/# ..,.. ... _,_,_~-'iz+p 

--""" 7' - ..... __ ,... i~ ~ .... ,,.=JI\;~ dd'"#,...u '= z ';114 .... ~ ... =.r= ""'""'" ... ..,.. = - z '1 "1 ~;,==Ii k'h') ,.,._ J~,,.Ao~S =,.Nii-Ji Z"_,...A.,..'1 T--. ~ 

--- -

Figure 13. 

19 OONFIBElN'l'IA:l:i 
REF ID:A63860 

C6NFIBEN'f'l2\L 

In the Middle Ages cryptography appears first as a method of concealing proper names, usually by the simple substitution of each letter by the next one in the alphabet, just about as 

Augustus Caesar did hundreds of years before. At other times the vowels were replaced by 

dots, without changing the consonants-a method that was used throughout Europe to about 

1000 A.D., when letters began to be replaced by various signs, by other letters, by letters from 

another language, by runes which are found in abundance in Scandinavia, and by arbitrary 

symbols. Figure 14 is an example of a runic inscription on a stone that stands before Gripsholm 

Castle near Stockholm, Sweden. The word rune means "secret." 

Within a couple of hundred years the outlines of modern cryptography began to be formed by 

the secret correspondence systems employed by the small Papal States in Italy. In fact, the 

real beginnings of systematic, modern cryptology can be traced back to the days of the early 

years of the 13th Century, when the science began to be extensively employed by the princes 

and chanceries of the Papal States in their diplomatic relations amongst themselves and with 

other countries in Europe. The necessity for secret communication was first met by attempts 

inspired by or derived from ancient cryptography, as I've outlined so far. There was a special 

predilection for vowel substitution but there appeared about this time one of the elements which 

was later to play a very prominent role in all cipher systems, an element we now call a syllabary, 

or a reperlory. These were lists of letters, syllables, frequently used parts of speech and words, 

with additions of arbitrary equivalents for the names of persons and places. There is still in 

existence one such-syllabary and list of arbitrary equivalents which was used about 1236 A.D., 

and there are other examples that were used in Venice in 1350. 

Figure 14.-A Couple of Old Ruins. 

20 
REF ID:A63860 

Among examples of ciphers in medieval cryptography is a collection of letters of the Archbishop of Naples, written between 1363 and 1365, in which he begins merely with symbol substitutions for the vowels and uses the letters that are actually vowels to serve as nulls or nonsignificant letters to throw the would-be-cryptanalyst off the right track. As a final development, the high-frequency consonants L, M, N, R, and S, and all the vowels, are replaced not 

only by arbitrary symbols hut also by other letters. 

About 1378 an experienced cryptologist named Gabriele Lavinde of Parma was employed as 

a professional by Clement VII and in the Vatican Library there is a collection of ciphers devised 

and used by Lavinde about 1379. It consists of repertories in which every letter is replaced 

by an arbitrary symbol. Some of these ciphers also have nulls and arbitrary equivalents or 

signs for the names of persons and places. There is a court cipher of Mantua, dated 1395, that 

used this system. 

At the beginning of the 15th Century the necessity of having variants for the high-frequency 

letters, especially the vowels, became obvious. Figure 15 is an alphabet of that period which 

is interesting because it shows that even in those early days of cryptology there was already a 

Figure 16. 

recognition of the basic weakness of what we call single or monoalphabetic substitution, that 

is, where every letter in the plaintext message is represented by another and always the same 

letter. Solution of this type of cipher, as many of you may know, is accomplished by taking 

advantage of the fact that the letters of an alphabetic language are used with greatly differing 

frequencies. I don't have to go into that now because many of you, at some time or other, 

have read Edgar Allan Poe's "Gold Bug," and understand the principles of that sort of analysis. 

It is clearly shown in the figure that the early Italian cryptographers understood the fact of 

varying frequencies and introduced stumbling blocks to quick and easy solution by having the 

high-frequency letters represented by more than a single character, or by several characters, 

as you can see. I will add that the earliest tract that the world possesses on the subject of 

cryptography, or for that matter, cryptanalysis, is that which was written in 1474 by a Neapolitan, whose name was Sicco Simonetta. He set forth the basic principles and methods of 

solving ciphers, simple ciphers no doubt, but he describes them and their solution in a very clear 

and concise form. 

Cipher systems of the type I've described continued to be improved. In Fig. 16 is shown 

what we may call the first complete cipher system of this sort. There are substitution symbols 

21 
REF ID:A63860 

OONFIBEN"f'IAL 

for each letter; the vowels have several equivalents; there are nulls; and there is a small list 

of arbitrary symbols, such as those for "the Pope," the word "and,'' the conjunction "with,'' 

and so on. This cipher, dated 1411, was used in Venice, and is typical of the ciphers used by 

the Papal chanceries of those days. 

A B c D•E F G H I .L M N!O'P Q·R s T u v NULLE t;I = Paoa 

1'9 7 'it 2 ~ ,, J.. \:') -+ 14 9 G '1 :1~ 5,5 b ca I.fl :. =et 

0: * x -¢- f" H'H '1'<!1(£ ~ =c:on 

¥, ' + T :r. :c tll 0 p '2f <f' =quo I i 

Figure 16. 

The step remaining to be taken in the development of these ciphers was to expand the "vocabulary,'' that is, the list of equivalents for frequently used words and syllables, the names 

of persons and places, parts of speech, and so on. This step was reached in Italy during the 

first half of the 15th Century and became the prototype of diplomatic ciphers used in practically all the states of Europe for several centuries. One of 70 ciphers collected in a Vatican 

codex and used from about 1440 to 1469 is shown in Fig. 17. Note that the equivalents of the 

plaintext items are Latin words and combinations of two and three letters, and that they are 

listed in an order that is somewhat alphabetical but not strictly so. I suppose that by constant use the cipher clerks would learn the equivalents almost by heart, so that an adherence 

to a strict alphabetic sequence either for the plaintext items or for their cipher equivalents 

didn't hamper their operations too much. In Fig. 18 there is much the same sort of arrangement, except that now the cipher equivalents seem to be digraphs, and these are arranged in 

a rather systematic order for ease in enciphering and deciphering. Now we have the real beginnings of what we call a one-part code, that is, the same list will serve both for encoding and 

decoding. These systems, as I've said, remained the prototypes of the cryptography employed 

throughout the whole of Europe for some centuries. The Papal States used them, and as late 

as 1793 we find them used in France. I wish here to mention specifically the so-called King's 

General Cipher used in 1562 by the Spanish Court. It is shown in Fig. 19. 

But there were two exceptional cases which show that the rigidity of cryptographic thought 

was now and then broken during the four centuries we have been talking about in this brief 

historical survey. Some of the Papal ciphers of the 16th Century and those of the French 

GON.FIBBH'l'IA:L 22 
.. 

REF ID:A63860 

00~1rPIBf1N'f'l2tL 

Court under Kings Louis XIII and XIV exemplify these exceptions. In the case of these 

French Court ciphers we find that a French cryptologist named Antonio Rossignol, who was 

employed by Cardinal Richelieu, understood quite well the weaknesses of the one-part code and 

syllabaries. It was he who, in about 1640, introduced a new and important improvement, the 

idea of the two-part code or syllabary, in which for encoding a message the items in the vocabulary are listed in some systematic order, nearly always alphabetical; the code equivalents, 

whatever they may be, are assigned to the alphabetically listed items in random order. This 

means that there must be another arrangement or book for ease in decoding, in which the code 

-·~--.......... a 7~=-~ '-'--; "" , ~-C...,•t~ '\J!u-a;...,,4 

• L c \ <t f ~ !. 1 i" •n ':- n o }' r ( t- u ~ v ~ · 7 " 1.[... 

1 :f f ~ ~ ~ 'f . o ., -.,. ')' {> lr J, ~ i, _:- °* ~ ~f, A ,~. 'I' , • ":I. ~ n t: tt .,,, l-" 

~ l r,'"· ~ c-i,P-t 

-- llu!k ~ rt" 11 a ·111-1 quc 'P' If'" .ii. 

• ""' - 11' • • · \;,,~ 

~·-·- .. :....I' . '" .-b <"(' .... b 

- -.: tlWf~\ ff ff i'.'t'.; Ji "\''" nn rt ~ !I ,.,,., .tti J:f • .. 

..... ! . 

''"''"'" {."'-u~ . 

~ ... ~. 

{""i,.]lf;,,. 

C....~CV•' 

bcn1U1 

~ ........ 

Figure 17. 

23 

$c 

... , ... ,. tr 

'-::uL1n l..i 

$ct.. b1l ,,,tp1 l .. ! 

~ ... ~ • .i ~ l...-, 

d-c .... -::J·'cl..: <:C 

:t-"'no n 

........ .,,~. "" ..;-..-!..: ... f , •• i..r.:. 

I 1.\ ....... ~ .... ~ff .,. ~~ ..... : -}' nt.l 

--i:'nY\1hn 1t'1 J!ececu.. .:'J!C 

i..... .,,. fn1:atC\01 ~ ~:. 

-\,:'k'-l'U'l~ ~.2 

--..-ct~ nan 

~ \," . cwn 

, r ... ~ '""'~ 

:--~z- = 

·7"«ft0 

i;-~ '""" tt/: 

~ ....... · ... .; 

•• ,~ • !- •• ..,!It I 

I 

·~ I .... 

~ 
REF ID:A63860 

equivalents are listed in systematic order, numerically or alphabetically as the case may be, 

and alongside each appears its meaning in the encoding arrangement, or book. The significance 

of this improvement you'll find out sooner or later. Codes of this sort also had variantsRossignol was clever, indeed. One such code, found in the 1691 correspondence of Louis XIV 

had about 600 it.ems, with code groups of two and three digits. Not at all bad, for those days! 

Now this sort of system would appear to be quite secure, and I suppose it was indeed so, 

for those early days of cryptographic development-but it wasn't proof against the cleverness 

Figure 18. 

24 
11r. &1& 11.0& .. 

a. p c:. d. e.. J 

,, If elf "" Ji. E 

'Y CIC. 

....... 0 

lo p ct 'f" s t. 

I~ )(' ':I '3E ~ 'V' 

? of; 

l 20 

J,a. 'be bl J,o iu I u "" -u ~ v+ 

J.a. de di J.o J.u I 

4.-c.. .a.c,. """' """ o£c.fo 

S'~ f'e t'..z° S'b f'U. .&. "!'- 4 er.. a+ 

]a Je ]~ Jo Ju. 

!!.' ~ ,,,, 2.e. :t.+ 

'ncii HM! :171.Z ""'° l:f'>W 

4 ; 't 4e. 4+ 

r:- pe. 1-?i po pu. 

' ~ ' ,_ '+ i-q fee ~i '1"0 1'"U 

r. ; ~ "It-

' t:a. te. ti. to tu. '+ 9 9- '· ,, 

REF ID:A63860 

J,. l I 

g .:z. 2tt.. n. 

1: ~ 4 8 '1 1 ~ &, 

~ 

y x y ~ 

" A Xt- V-e tJ' 

10 ' cp9 

CG. c:e c.z co cu. 

1'+ .y 'Y ":' .y 

fo fe fi. Jo fu :..t.. /l. A.. 4 A! 

:he .IQ. J..o 

Oto 0 0-

Figure 19. 

VONF:l.BBNT'blL 

lJUjilicre.s se;ra..n toJ.a-1 Zo.r Zetnu,.n&Ufrenu 

o COU"a.c.teres, j_W! tUNie-rew. ZU&c 

""-'la Za.rr11.&l.Zac yllc&-e.n.C..:-

e~ - ,_ - 9 1'«.le fl07" 'ft.z& 0 2'1. J Cj» toP ~ J'9 , 

~ 1- ss. 

of British brains, for the eminent mathematician John Wallis solved messages in it in 1689. 

Never underestimate the British in this science-as we'll have reason to note in another lecture 

in this series.* 

French cryptography under Kings Louis XV and XVI declined, reaching perhaps its lowest 

level under Napoleon the Great. It is a fact that in Napoleon's Russian enterprise the whole 

of his army used but a single code book of only 200 groups, practically without variants, even 

for the high-frequency letters. Furthermore, not all the words in a message were encodedonly those which the code clerk or the writer of the message thought were important. It's 

: pretty clear that the Russians intercepted and read many of Napoleon's messages-this com.es 

from categorical statements to this effect by Czar Alexander I himself. We won't be far wrong 

in believing that the weaknesses of Napoleon's crypto-communications formed an important 

factor in Napoleon's disaster. A hundred and twenty-five years later, Russian ineptitude in 

cryptographic communications lost them the Battle of Tannenberg and eventually knocked 

them out of World War I. 

The other 16th Century Papal ciphers that constituted the second exception to the general 

similarity of cryptographic systems of those days were quite different from those I've shown 

you. In this exception the ciphers were monoalphabetic, but some letters had the same equivalent, so that on decipherment the context had to be used to decide which of two or more possible plaintext values was the one meant by each cipher letter. One such cipher used by the 

Maltese Inquisitor in 1585 is shown below: You'll note that the digit fJ has two values, A and 

• Official deciphering of foreign communications by British cryptanalysts can be traced back to about the 

year 1525, if not earlier. 

25 
REF ID:A63860 

CONFIBBN'f'IAL 

Plain: A,T 

Cipher: ¢ 

Nulls: 1,8 

Plain: qua 

Cipher: 7 

CIPHER OF THE INQUISITOR OF MALTA (1585) 

(From SACCO, MANUALE DI CRITTOGRAFIA, 1947) 

E,F I,G O,D U,V,B C,L,N M,R P,S,Z 

3 5 4 2 6 9 7 

que qui quo che chi non quando percha et 

9 6 2 4 5 3 ¢ 1,8 

per 

T; the digit 2 has three values, U, V, and B, and so on. There were two digits used as nulls, 

1 and 8; digits with dots above them stood for words such as qua, que, qui, and so on. 

Below is shown a message and its encipherment: A bit tricky, isn't it? Many, many years 

later Edgar Allan Poe describes a cipher of this same general type, where the decipherer must 

choose between two or more possible plaintext equivalents in building up his plain text, the 

latter guiding the choice of the right equivalent. The trouble with this sort of cipher is that 

you have to have pretty smart cipher clerks to operate it and even then I imagine that in many 

places there would be doubtful decipherments of words. It wasn't really a practical system 

even in those days, but it could, if used skillfully and with only a small amount of text, give a 

cryptanalyst plenty of headaches. But such systems didn't last very long because of the practical difficulties in using them. 

Cipher: 4 5 1 ¢ 2 ¢ 4 1 4 ¢ 9 4 8 9 5 6 2 ¢ 4 1 ¢ 2 5 7 4 

"Plain": {° I 

AU A 0 0 A M 0 M I C U A 0 A U I P 0 

D G TB TD D TR D RGLBTD TB GS D 

v NV v z 

Plain: D I T U T 0 D A R 0 M I N U T 0 A V I S 0 

Cipher: 1 4 5 6 5 1 6 4 9 5 3 9 3 8 

"Plain": t 0 I C I C 0 M I E M E 

PER D G LG NDRGFRF 

PER CHE N L 

Plain: PER 0 G N I C 0 R I E R E 

The first regular or official cipher bureau in the Vatican was established in about 1540 and 

in Venice at about the same time, about one hundred years before a regular cipher bureau was 

established in France by Cardinal Richelieu. It is interesting to observe that no new or remarkable ideas for cryptosystems were developed for a couple of hundred years after the complex ones I've described as having been developed by the various Papal cryptologists. Onepart and two-part syllabaries and simple or complex ones with variants were in use for many 

decades, but later on, in a few cases, the code equivalents were superenciphered, that is, the 

code groups formed the text for the application of a cipher, generally by rather simple systems 

of additives. Governmental codes were of the two-part type and were superenciphered by the 

more sophisticated countries. 

The first book or extensive treatise on cryptography is that by a German abbot named 

Trithemius, who published in 1531 the first volume of a planned monumental 4-volume work. 

I said that he planned to publish four volumes; but he gave up after the third one, because he 

wrote so obscurely and made such fantastic claims that he was charged with being in league 

with the Devil, which was a rather dangerous association in those or even in these days. They 

didn't burn Trithemius but they did burn his books. Figure 20 illustrates that the necessity 

for secrecy in this business was recognized from the very earliest days of cryptology, and cerCONli'IBBN'f'fAL 26 
REF ID:A63860 

tainly by Trithemius. Here is the sort of oath that Trithemius recommended be administ.ered 

to students in the science of cryptology. All of you have subscribed to a somewhat similar 

oath, but we now go further and back up the oath with a rather strict law. You've all read it, 

I'm sure. 

~~ ~i:t~lan (l)ath ~-, J]ib.en br!J ,.,, 

~lohtmtte15 ~ ltiym.iuss ._, 1tt 

follkll,«f)apttr XXl~J1f ¥s"~te~a110~!JI"J3~la: 

Figure 20. 

We come now to some examples from more recent history. In Fig. 21 we see a cipher alphabet used by Mary, Queen of Scots, who reigned from 1542 to 1567 and was beheaded in 1587. 

In this connection it may interest you to learn that question has been raised as to whether the 

Queen was "framed" by means of this forged postscript (Fig. 22) in a cipher that was known 

to have been used by her. 

27 CON-FIBBN'.HAL 
REF ID:A63860 

The Spanish Court under Philip II, in the years 1555-1598, used a great many ciphers and 

here's one of them (Fig. 23). You see that it is quite complex for those early days and yet 

ciphers of this sort were solved by an eminent French mathematician named Vieta, the father 

of modern algebra. In 1589 he became a Councelor of Parliament at Tours and then Privy 

Councillor. While in that job he solved a Spanish cipher system using more than 500 characters, so that all the Spanish dispatches falling into French hands were easily read. Philip was 

so convinced of the security of his ciphers that when he found the French were aware of the contents of his cipher dispatches to the Netherlands, he complained to the Pope that the French 

were using sorcery against him. Vieta was called on the carpet and forced J;o explain how 

he'd solved the ciphers in order to avoid being convicted of sorcery, a serious offense. 

Figure 21. 

,,l°Jj,..i;r-'4 ;.1._. ..... ,.vlf..-C-6 p•f'Ao~ ~ u ... , 1. 6 ... ~.111 • ..._,7 _..,_,,, ., ... , ... ti 

-#~fa.•V•A-V""~.,,~-~-r--va-•/f_...,·"f(f 1¥11.P•f.f:AJ. .. •••F1'"-•••-.6il•, 

-vJfl/y,.,.. ...... 1_s~s•/t1•.&.'vP'-~""-l#flaae/•l••c•.1L ... fA,.;,._._ I 

.,/,-.,.,_f:,._,,,, • ._,..c .. A-.,,, .. r.a;I.'- c·f.# · 1 s s t'z a , g • -. 

::z~;: '::::: :::·· -;;~;.,,. •<••• ~-1.,.~~.!I._,,_.. : J ' r n • •-;P-X 11,.- I 'ff' f 'I" f • / £ I A C ,. • l-•1-..•.; . , . e-"''f T"A••~ ....... 2.!!-#'f .... • 4'•11tll ..S•~ .. 1r,.1 ''.A.." e-•vJa.-• .,~ .. 

"'*I'"._., .,•-P•/-- ... ~ ... It v_J',.,f f 1e b.-...-.. /, ... ,f f.'1' r.1~ /'/'" 

111• H•IU.l ll I'"' I •l IUl' I, \\ 1111 1'1111111''' I 'lllllt•I '\U' I 

Pial• 11 K.1 •r1l I Uh1L 

Figure 22. 

28 

' . 
REF ID:A63860 

; x.e X."<. ,..,, IC.~ 'Y"' 'f• yi yo yu. 

8'"+ i $'-6'" :f-e. fr.' kt r: fa., li.-e 

:ta- , x.e ~ ... x..o lC.U. pl.o. Jle p~i b'IP jl.u. 

I I+ I fr l"f 11- !!! 11- tP' ~ 

~ 'Pre bri PPO ;ru c7LC11 che c'IU. CM clr.u. "l'1F fl:. TU TV e>' (» Ii ()6- Oe 

cloc c:Ze. cZi clo du e~ ere c:~i cro CPU 

1 ~ ~ ~ 9-c So ~ :1- s. 9...o 

c:1.- clre J..-C d.:ro d.n. fl;ot. p.e f.li. flo !f._iu ,; Ht- % .g.. -8-e 1 'I!- 1 .,.. "]:. 

If':'" foe ftr;L fN> lfru S'l"" 1°Le :r-ti. g'lo ~lu. 

..,. 7+ '1- .,.,. ff. ~ Gr f;" ~ G-e 

~ ~ ¥- ~ ~· j6~ ,l.e 't'_li 'f>UJ !plu. 

1¥-e g, ~ ci g.. ~ 

mo ~- fr;'" 'fa?O ~ tttJt. .. ~ 'tr~ z:..., bu. 

-et:. ett- -a: -Pl ~ -& -er ~ 

1 el il oZ. u.l <=141. 11!.11. t;n OM. ............ _ 

r+ ~ lfr ~ a- a+ a- ~ cS'"'f. 

a..- er ir or ur 0'4 e1 i-s or ~ 

4- +.. + ~ +e " . 1)+ u 1.16'" ve 

!lcu ;Je,. 'bir r.01"' kt~ Ja.,s /Je1 '1ir Por '1U4 

g ~ J" ~ 6-e ? ?+ ? ?"' re 

ccr cer t co,.. Co.Ir cr:u ces C'L4 c.os CU4 

:;J. ~ ~ ~ D' .D+ n D.c The 

r. -

b d f (I• h fTlf1n1 I a c c IA B 0 

I n 0 "P q "[' s t v x;y z! 

!en a b c d e 1' g- h ]. 1 m: 

I 7. n 0 "P q r s t v x yl 

EF a 1> c a. e £ g 11 i 1 Im 

y z n 0 "'P q r s lv .x 

·GH a b c Id e f 8' lh i 1 m1 

x y z n 0 "P q r s t v 

IL a b c Id e f 8' lh 1. I ~ 

v x y z n 0 l> IQ r s l 

l\rN a b c 'd e f g-!h "1 1 iill 

t v x IY z n 0 1> Q r s 

OP a t> c d e -r g- n i l lJl 

'~ l v x IY z n 0 11> q r 

2R a b c d e .f g' b i l m 

]) s t v x y z n 0 11> Q 

ST a l> c d e f g b i I 1-Dl 

q "P s t. v .x IY z n 0 p 

vx a b c a. e f 8' b i l m 

p lq r s t v :x y z n 0 

yz a 0 c d e r g n i 1 m 

0 p q 1' s t v :x IY z TI 

Figure 23. Figure 24. 

The next cryptologist I want you to know something about is another Italian savant who 

wrote a book, published in 1563, in which he showed certain types of cipher alphabets that 

have come down in history and are famous as Porta's Alphabets. Figure 24 is an example of 

the Porta Table, showing one alphabet with key letters A or B, another alphabet with key 

letters C or D, and so on. I don't want to go into exactly how the key letters are used; it is 

sufficient to say that even to this day cryptograms using the Porta alphabets are occasionally 

encountered. 

That Porta's table was actually used in official correspondence is shown by Fig. 25, which is 

a picture of a table found among the state papers of Queen Elizabeth's time; it was used for 

communicating with the English Ambassador to Spain. Porta was, in my opinion, the greatest 

of the old writers on cryptology. I also think he was one of the early, but by no means the 

first, cryptanalyst able to solve a system of keyed substitution, that is, where the key is changing 

consistently as the message undergoes encipherment. Incidentally, Porta also was the inventor 

of the photographic camera, the progenitor of which was known as the camera obscura. 

Figure 26 is a picture of what cryptographers usually call the Vigenere Square, the Vigenere 

Table, or the Vigenere Tableau. It consists of a set of twenty-six alphabets successively displaced one letter per row, with the plaint.ext letters at the top of the square, the key letters at 

the side, and the cipher letters inside. The method of using the table is to agree upon a key 

word, which causes the equivalents of the plaint.ext letters to change as the key changes. Vigenere is commonly credited with having invented that square and cipher, but he really didn't 

and, what's more, never said he did. His table, as it appears in his book, the first edition of 

which was published in 1586, is shown in Fig. 27. It is more complicated than as described in 

ordinary books on cryptology. 

Figure 28 is one more example of another old official cipher. In it we can see the alphabets 

which could be slid up and down, as a means of changing the key. Another early official cipher 

is shown in Fig. 29. It is a facsimile of a state cipher used in Charles the First's time, in 1627, 

29 
REF ID:A63860 

CONPl1'EN"f'IAL 

Figure 26. 

for communicating with France and Flanders. It involves coordinates, and I want you to notice that there are two complete alphabets inside it, intended to smooth out frequencies. The 

letters of the key words OPTIMUS and DOMINUS serve as the coordinates used to represent 

the letters inside the square. A third old cipher, one used by George III in 1799, is shown in 

Fig. 30. 

One writer deserving special attention as a knowledgeable cryptologist in the 17th Century, 

and the one with whose cipher I'll close this lecture, is Sir Francis Bacon, who invented a very 

useful cipher and mentioned it for the first time in his Advancement of Learning, published in 

1604, in London. The description is so brief that I doubt whether many persons understood 

what he was driving at. But Bacon described it in full detail, with examples, in his great book 

De Augmentis Scientiarum, which was published ahnost 20 years later, in 1623, and which first 

appeard in an English translation by Gilbert Wats in 1640 under the title The Advancement of 

Learning. Bacon called his invention the Bilit;eral Cipher, and it is so ingenious that I think 

you should be told about it so that you will all fully understand it. 

In his De Augmentis Bacon writes brie:fty about ciphers in general and says that the virtues 

required in them are three: "that they be easy and not laborious to write; that they be safe, 

and impossible to be deciphered without the key; and lastly, that they be, if possible, such as 

not to raise suspicion or to elude inquiry." He then goes on to say: "But for avoiding suspicion 

altogether, I will add another contrivance, which I devised myself when I was at Paris in my 

early youth, and which I still think worthy of preservation." Mind you, this was 40 years 

later! Let's consult Bacon for further details. In Fig. 31 we see a couple of pages of the 

Gilbert Wat's translation of Bacon's De Augmentis Scientiarum. Bacon shows what he calls 

CONFIBBN'HAL 30 
REF ID:A63860 

OONPIBfi1N'f'f2tl; 

A B CD EF GB I J KL MN OP 0 R ST u v w x YZ 

A ab c d e f ~ h i .i k 1 m no p l1 rs t u v \V x y 1. 

B b c de f 1t h i .i k 1 m 11 Oip Q r. s t \I v w x v z a 

c c d e r $! h l j k lm no p q :r s t u vw x y z a b 

D de r 1!' h l .i k 1 !JD. no p q p s t u vw x y z a b Cl 

E e r g h l J k 1 Im no p 1q "P s tu vw XIY z a b c d 

F f ft h l J k l 1m no p q :r s tu vtw .x y z a b c d e 

G <§ h 1 J k I tm no 11> qp s t u v IW xy z a b c d e f 

H h ilj k 1 Im n OIP q p s t u VIW xy z a b c d c f 8 

I i j k I tm no 11> IQ rs l u vw xy z a 0 C;d e f g n 

J J k I Im no p q PS t UV w xy z a b c d e f g h i 

K k 1 m no ID qr s l UV 1W X .Y z a b cd e f g' b i j 

L I lDl D 0 p IQ r s l u v IW x y z a t> c let. e r g h i J 

M m n 0 1> a r s t u v IW x y z ab c d e f !f h l j k ~~ N n 0 11> q r s t u v ~ x IY z a b c d e r g n i J k 1 ml 

0 IP IQ t IW .V b c d r g" h j k 1 -I 0 p s u v x z a c 1 ~ ..!.~ p p q p s l u v IW x y z a b c de f 1': h i j ]( .~:n n ~l 0 q r s l u v w x IY z a b c d e r j?' h i J k r rm n 0 IP' 

R PS tu vlw XIY z a b c d c r f h 1 .i k l 1111 no It> q 

s s l UV \1\1 xy z a lb c a e r gn l J k 1 m no pq 1' 

T t u v l\IY x .y z a b c Id e r g lh 1. J k l [1Il no l> q r 

u u v IW x y z a b c a c f lg b l j k 1 rm n OIP q 1' s ~ v tv w x y z a t> c d c f 1! h 1 J k I 1111 n 0 11> q r s ( \11 

w IW x y z a b c d e f g b 1 J "k 1 rm n 0 p i q l' s l u vi 

x x l.V z a b c d. e r g n l J k 1 m n 0 IP q r s l u v wl 

y IY z a b c d e f g h I j k 1 ID1 n 0 IP 1q r s l u V !W xi :.i z z a :b c Id e f' 1( h J lj lk l IIll n 0 'P lq I' s l 1U v 'WJX YJ 

Figure 26. 

'= ;01PIQ:R 1s IT 1v1x IA IBICIDIE IF IG IH II ILIMIN - f.elFIGl.1:1[1ILIMIN!olP IQ.In ls Ir lvlxl.Ajslc ID ,_ '= j.i. lb le Id le If lg lh 11 0 L II Im l•l lo IP lq Ir IL" It Iv Ix 

i> J: lb le Id le If lg lh 11 \l lmln lo \p \~~J:Jv Ix la 

<i. .<.l.. c Id le If lg \h Ii IL Im In lo IP jq Ir If It \v Ix la lb 

R- (! /d le If lg lhLl!_ Im In J.~Jr_ltl_l~v Ix la lb le 5·· L j:J! . .Jg; lh 11 II Im In lo IP lq Ir If [t Iv Ix in lb le Id 

·r .1_ :f lg lh 11 11 lmln lo IP Ill Ir If le 1~~1 jb le~ 1\,-

I~ lg p1 Ii 11 !min lo IP lq 11 If le :v Ix l.1 ~b le Id Ir.: It 1_ 

.h. h 11 11 Im In lo Ip l·l Ir IC le Iv .x l:t lb le Id le If lg 

,t\ 11 II !min lo Ip 1·1 Ir II It Iv Ix l.1 ji;-j~-FI le If lg ;h 

B- ,.p I Im In lo IP lq Ir If It Iv \x l.i lb le Id le If lg lh 11 

c 'min [o Ip lq Ir If It Iv Ix l:t lb le Id le If lg [h Ir II 

l) 1: 11 lo IP lq Ir 1r It Iv Ix 1.1 lb le Id le If lg lh Ii 11 l'n 

E 1~J.~._Lq Ir If It Iv Ix la lb le Id le If lg I h 11 II_ !min 

F I~ P 111 Ir If It Iv Ix la lb !e Id le If lg lh !• ii I~~ 

G 1·1 Ir If le Iv Ix la ltl le Id le If lg \h !1 II l1n [n lo \p 

H 

"~ r \C It Iv Ix la lb le Id ;e If \g jh 11 [I lm!n lo Ip lq 

r r It Iv Ix 1.1 lb je Id.le If I~ lh 11 11 In In lo Ip lq Ir 

L B t Iv jx l.1 lb le Id le If lg ih Ii fl Im 111 lo 1p lq Ir IC -

M c v Ix la lb le Id le If lg lh 11 II !min lo IP lq jr II It 

N !) x [a lb le Id le If lg lh !1 II jm!n jo Ip lq Ir jf TtT 

Figure 27. 

31 OONMBHN'f'IAL 
REF ID:A63860 

"An Example of a Bi-literaire Alphabet," that is, one com.posed of two elements which, taken 

in groupings of fives, yields 32 permutations. You can use these permutations to represent the 

letters of the alphabet, says Bacon, but you need only 24 of them [because I and J, U and V, 

were then used interchangeably]. These permutations of two different things-they may be 

"a's" and "b's", "l's" and "2's", plusses and minuses, apples and oranges, anything you pleasecan be used to express or signify messages. Bacon was, in fact, the inventor of the binary code 

which forms the basis of modern electronic digital computers. Bacon gives a brief example in 

the word "FUGE"-the Latin equivalent for our modern "SCRAM"-as can be seen in Fig. 

31. Figure 32 is another example, which quite obviously isn't what it appears to be-a crude 

picture of a castle, in which there are shaded and unshaded stones. It was drawn by a friend 

who was a physician and the message conveyed by it is: 

My business is to write prescriptions 

And then to see my doses taken; 

But now I find I spend my time 

Endeavoring to out-Bacon Bacon. 

Figure 28. 

32 

Figure 29. 
.,. 

REF ID:A63860 

So far all this is simple enough-too much so, Bacon says, for the example he used in the 

case of the word FUGE is patently cryptic and would not avoid suspicion under examination. 

So Bacon goes on to describe the next step, which is to have at hand a "Bi-formed Alphabet," 

that is, one in which all the letters of the alphabet, both capital and small, are represented by 

two slightly different forms of letters (Fig. 33). Having these two different forms at hand, 

when you want to encipher your secret message, you write another external and innocuous message five times as long as your secret message, using the appropriate two forms of lett.ers to 

correspond to the "a's" and "b's" representing your secret message. Here's FUGE (Fig. 34), 

enciphered within an external message saying "Manere te volo donec veniam," meaning "Stay 

where you are until I come." In other words, whereas the real message says "SCRAM," the 

phoney one says "Stick around awhile; wait for me." Bacon gives a much longer example, the 

SPARTAN DISPATCH; here it is, and here's the secret message which it contains (Fig. 35). 

Bacon's biliteral cipher is an extremely ingenious contrivance. Th.ere can be no question 

whatsoever about its authenticity and utility as a valid cipher. Thousands of people have 

checked his long example and they all :find the same answer-the one that Bacon gives. 

Figure 36 is a modern example which uses two slightly different fonts of type called Garamond 

and Imprint, and which are so nearly alike that it takes good eyes to differentiate them. 

The fact that Bacon invented this cipher and described it in such detail lends plausibility to 

a theory entertained by many persons that Bacon wrote the Shakespeare Plays and that he inserted secret messages in those plays by using his cipher. If you'd like to learn more about 

this theory I suggel3t with some diffidence that you read a book entitled The Shakespearean 

Ciphers Examined. I use the word diffidence because my wife and I wrote the book which was 

published in late 1957 by the Cambridge University Press. 

In the next lecture we'll take up cryptology as used during the period of the American Revolution by both the Colonial and the British Forces in America. 

Figure 30. 

33 
CONFIBBN'f'IAL 

OONFIBl!lH':Fll.:L 

REF ID:A63860 

01! THE ADV AN CEMENT 

Ncithcr 1s it a fmall matter theft Cypbtr-Cb4raEltrs have,and 

may pcrformc: For by dus Art a way is opened, \Vhcrcby a 

man may cxprdfe and ligmfie the mtcnnons of his mmdc1 at 

any ddlance of place, by ob1cB:s which may be prcfcnccct co 

ihccyc, and aa:ommodated co chc care : provided chofc ob. 

jcfts be capable of a twofold d1ffi:rcncc onely 1 as by Bells, by 

Trumpets, by L1ghcs and Torches, by chc report ofM11skcb, 

and any mRrumcncs of like nature. But to purfuc our cnccrpnf c, when you addrclfc your felfc co write, rcfolvc your inward-intoldcd Lcctcr mco this qj1-httr.irir .Alp1111btt. Say the 111• 

,,,_ Lrttrrbc 

F11gr. 

E.xamplr ofSJutirm. 

31. §. £ 

G"'Jf. uffa. ad"u. 

Togcdvz 

Figure 31. 

Figure 32. 

34 
.. 

.. 

REF ID:A63860 

0 F LE ARN l NG. LIB. v I. 167 --- Togctherwith this,you mull have ready at hand a13i{ormtJ. 

.Alpbabtt, which may reprcfent all the Letters of the Common &. 

pbabet, as well Cap1call Letters as the Smaller CharaC\:ers in a 

oouble forme, as may fit every mans occation • 

.An Examplt of a 13iformtJ Alpbabtt. 

{ 

~. (.a. I. d,. t: LA 4 t: a.f. 4. b. IL. 6. 

vi ff a:a.:B.~ lf. C. cf.v.c.~m£t: 

5 "' {. ,,..( "'· t. J. "'· .t. It. t. d.. £'.a.. t. 

l~ e.e.c.7. ~ §. g' tf$!£.f1£Xf'. 

.f~ fJ. "'· f. a.1:11.I. a.f. a. b.a.f. 

iff $£.i.J(ff(U.{:f:./ f'..ftGf:m.m. 

r': ~.a.Li. f.4.t. 4.1.4.f. a. . .r. a..r. a,. 

~a 8.o.~P.fl.J·Q~.f j·~ 

~ t:. (/,.(.fl,,.(.,£ 4. { J. a.. t. a..f. 4. f. 

l~S.S..u-.T.q_""r. ~4?21.~.tt.-1h 

5 ¢. t. ""I. tt. (. 4.{ 4. t. a.b. ~.a..f. 

iw.tfP..,.1).re.. ~=-oeY~.rJ~ 

Lis Now 

Figure 33. 

35 
REF ID:A63860 

CONPIBBfffML 

o. T•I! ADTAMCl!MllKT ~· Lau.x1xa. L1a.vr. 

Figure 34. Figure 31. 

In ali duty or rather piev towards you I satisfy every body except 

myself. M;yself I never satisfy. For so great are the services which J'OU 

have rendered me, that seeing you did not rest in your endeavours on my 

behalf till the thing was done, I feel as if life had lost all its sweetness, 

because I cannot do as much in this cause of yours. The occasions are 

these: Ammonius the King's ambassador open!J besieges us with money: 

the business is carried on through the same creditors who were employed 

in it when vou were here, &c. 

Figure 36. 

CONPIBHN'l'IA:L 36 
.,. 

REF ID:A63860 

Lecture Ill 

Continuing with our survey of cryptologic history, the period of the American Revolution, 

in U. S. history, is naturally of considerable interest to us and warrants more than cursory 

treatment. Information regarding the codes and ciphers employed during that period has been 

rather sparse until quite recently, when a book entitled Turncoaf:s, Trait.ors and Heroes by Col. 

John Bakeless, AUS, was published in 1959 by Lippincott. Aft.er a good many years of research Col. Bakeless brought together for the first time a considerable amount of authentic information on the subject, and some of it is incorporated in this lecture. 

According to Col. Bakeless-and believe it or not-in early 1775 the British commander-inchief in America, General Gage, had no code or cipher at all, nor even a staff officer who knew 

how to compile or devise one; he had to appeal to the commanding general in Canada, from 

whom he probably obtained the single substitution cipher which was used in 1776 by a British 

secret agent who-again, believe it or not-was General Washington's own director-general of 

hospitals, Dr. Benjamin Church. General Washington had means for secret communication 

from the very beginning of hostilities, probably even before the fighting began at Lexington 

and Concord. If the British under General Gage were poorly provided in this respect, by the 

time Sir Henry Clinton took over from General Howe, who succeeded Gage, they were much 

bett.er off-they had adequate or apparently adequate means for secret communication. 

Are you astonished to learn that the systems used by the American colonial forces and by 

the British regulars were almost identical? You shouldn't be, because the language and backgrounds of both were identical. In one case, in fact, they used the same dictionary as a code 

book, something which was almost inevitable because there were so few English dictionaries 

available. Here's a list of the systems they used: 

a. Simple, monoalphabetic substitution-easy to use and to change. 

b. Monoalphabetic substitution with variants, by the use of a long key sentence. I'll show 

you presently an interesting example in Benjamin Franklin's system of correspondence with 

the elder Dumas. 

c. The Vigenere cipher with repeating key. 

d. Transposition ciphers of simple sorts. 

e. Dictionaries employed as codebooks, with and without added encipherment. Two were 

specially favored, Entick's New Spelling Dictionary, and Bailey's English Dictionary. A couple 

of pages from the former are shown in Fig. 37. To represent a word by code equivalent you 

simply indicated the page number, then whether column 1 or column 2 contained the word you 

wanted, and then the number of the word in the column. Thus: The word "jacket" would be 

represented by 178--2-2. 

f. Small, specially compiled, alphabetic one-part codes of 600-700 items and code namesour old friend the syllabary, or repertory, of hoary old age, but in new dress. In some cases 

these were of the "one-part" or "alphabetic" type. 

g. Ordinary books, such as Blackstone's Commentaires on the Laws of England, giving the 

page number, the line number and the letter number in the line, to build up, letter-by-letter, 

the word to be represented. Thus: 125-12-16 would indicate the 17th letter in the 12th line 

on page 125; it might be the letter T. 

h. Secret inks. Both the British and the Americans made extensive use of this method. 

i. Special designs or geometric figures, such as one I'll show you presently. 

j. Various concealment methods, such as using hollow quills of large feathers or hollowing 

out a bullet and inserting messages written on very thin paper. Strictly speaking, however, 

this sort of stratagem doesn't belong to the field of cryptology. But it's a good dodge, to be 

used in special cases. 

37 C~EN'l'IAL 
REF ID:A63860 

CON.FIBEl~IAL 

JAC JAU 

Hyp, v. •· te make mela•cholJ, to dlfpfrit Jack'daw,f. • chateaing bi ... Hypallage,f. • daange of cafes, td~. J•ck'ct, (. • wa1ftcoar .. a lhort Colt 

Hyper'bole,/. aa u1111ention, a dimieation Jaclr.'padding,f. 1111errJ anclrew, a hull'Mll 

Hyperbol1

1cal, •· nlftel'lling orcstenuaring J•c!omte1/. a parliHa of James II. 

Hyperll6rcan, •· non•ern (red'nn Jaftitbian,f. 1 tnlliDg motion, reftleffhel't 

• '~ y'per, Hypercri1'ie, J. 1 aitic ewa& !Morand !acul6tion, ~ the .a of throwing llr d1rti•1 

Hypercrit'ie1l, •· critical lieJOlld afe, fcwere .. de,f. a bd womaa, a worthier. horfa 

Hyper'mcter.j. what i1 abn"e rile ltaad1rd •de, "''a. to rire, ,,,..,,, ride dbwa, fidl& 

H) per(a1'"1i•, • a 1rowth of proud llelh .idith, •· anrul1, "icioas, uachale 

H>'phen,J. (· {•tween wordr or fyllablet •Fl• v .•• to norch;J.ade•dculatios,unneaMli 

H• pnot'11:,£: a med;cine cauliag llecp •&'11io1, J. 1 cutting ia utchu 

Hypochon dri111J. oae affcfted witbmeJaa~nl7 •r!F'/• •· unewn, notclaed 

Hypochon'driac•I, a. melancholy ail,/ a prifon, a1..S 

Ht'poc'rrfy,f. diaimutation, a ptetence ai'/er,[ the keeper of a prilotio • 

Hrp'o.rite,J. a d•lf•mbl•r ia reli1ion, &f~. akes,J. a houfe of olice, a bog\6ull 

H ypoc1 u'1cal, •· d1fl'cmbli11g, ialiacere, f11(e am, f. a coafene ol &uit, a cllild"1 lrodt Hypocrit'1~all:r1 till. ••tli"•' llr.cerity, falfe'y am,•·•· tn cnldlae lietweer, to wedp ia 

H) pug••'rric, & ia the lower put of the llelly am&, f. the apript pol of a door ' 

Hvp111'••li•,.f. a d1ftinft fabftarce, perlbnality 1m'bic,f. ver*a compoW of a Iona aMaltelt 

Hyp1.oftaf1c,1, .. conftitutin, daftin&, perfoaa• f•llable alternat.iJ 

Hypoth 16•,J. a l'Jftcm upon fu~politioa Jan'gle, v • ._ to -•qle, to he oatoftaaa 

Hy,iL•thet11c1I, "· fuppored, conditional f:a11'1aary,f. • Turllilt foldter, 11uard 

Hvo thet'.c11Jy, atl. up1111 turpofitioa •n'ry, .: llaowy, Autteria111 i;:ay, &iddy 

Hyrll, Hurll.,. Hcrft,J. a wood 3111111ry, r. the firll: month o( the year 

Hy,'f•r.,J. a plant t•pi.n,f. ·• nrnilla to wo1k lncalon 

H •'' 1 •c, •· troubled with lift •pan, "'· •· to va••illr, i. lll1ck •on 

H, !ler'ic., f. 11. liM of wome• apaw11er,-f 1 lhnebtacli:, one •ho j•rJUIW l. •r, v. 11 ,;, clalli, dif11A•, diWc., ~I 

/''°"• m)felf u,f. d1fcord, a badh found, an earthen Td'cl J, Jab'ber, .,. "'ta hllk idly, to chatter ""lo''gl~, v. ti· to conRiuall, perplex, panert 

J•b'be1er,/. one who hlk1 amntellig1blf Jar1gon,f.1ibberit11, gabb'e,nollfea• 

J1cinth,f. a g'911, the h7ac1a•h ••'per, 1: a precious pa ltoae 

Jack,f. Jnhn, an e.ngine, fill!, leathern eann n'•lin,/ a fpetr or half plb 

Jicent, "" lying at len11h, e11tended !"''•nine, Jo·f•m•n•,f. I A>lwrr 

J1ck'al,f. a be•ft tkat ltaru the lion'• prlJ •un'dic:e,J. a diftetnper • Jackallfnto/.' iniple tteepilh fellnw au111

d1ced, "· atre&ed with lhe jaandltl 

Jack.'a~MpU• ' a moalr.ey, a coircnmb aunt, v, •· to walk or lrorl •"ut 

j.&dt.bo{,ts9;-: bo• f11Y1t11 lw lllllor aunt,f. a r•llle, tac•llla, ftUJ 

laum'ilr. 

Figure 37. 

In the way of ciphers a bit more complex than simple monoalphabetic substitution ciphers, 

the British under Clinton's command used a system described by Bakeless in the following 

terms: 

" ... a substitution cipher .in which the alphabet was reversed, 'z' becoming 'a' and 'a' becoming 'z'. To destroy frequency clues, the cipher changed in each line of the message, using 'y' 

for 'a' in the second line, 'x' for 'a' in the third, and so on. When the cipher clerk reached 'o' 

in the middle of the alphabet, he started over again. A spy using this cipher did not have to 

carry incriminating papers, since the system was so easy to remember." 

The alphabets of this scheme are simple reversed standard alphabets: 

A B C D E F G H I J K L M N 0 P Q R S T U V W X Y Z 

Z Y X W V U T S R Q P 0 N M L K J I H G F E D C B A 

Y X W V U T S R Q P 0 N M L K J I H G F E D C B A Z 

X W V U T S R Q P 0 N M L K J I H G F E D C B A Z Y 

W V U T S R Q P 0 N M L K J I H G F E D C B A Z Y X 

V U T S R Q P 0 N M L K J I H G F E D C B A Z Y X W 

U T S R Q P 0 N M L K J I H G F E D C B A Z Y X W V 

T S R Q P 0 N M L K J I H G F E D C B A Z Y X W V U 

SRQPONMLKJIHGFEDCBAZYXWVUT 

RQPONMLKJIHGFEDCBAZYXWVUTS 

Q P 0 N M L K J I H G F E D C B A Z Y X W V U T S R 

PONMLKJIHGFEDCBAZYXWVUTSRQ 

0 N M L K J I H G F E D C B A Z Y X W V U T S R Q P 

OONFIBElNCJ?IMJ 38 
.,. 

REF ID:A63860 

COI\'"PfBEJN'FliY. 

Bakeless doesn't explain why the cipher sequences are only 12 in number- nor does the 

source from which he obtained the information, a note found among the Clinton Papers in the 

Clements Library at the University of Michigan. 

Bakeless continues: 

"Clinton also used anoLher subsLiLuLion cipher, wiLh diJl'erenL alphabets for the ilrst, second 

and third paragraphs. Even if an American cryptanalyst should break the cipher in one paragraph, he would have to start all over in the next. As late as 1781, however, Sir Henry was 

using one extremely clumsy substitution cipher, in which 'a' was 51, 'd' was 54, 'e', 55. Finding 

that 'a' was 51 and 'd' was 54, anyone could guess (correctly) that 'b' was 52, 'c' 53. Somewhat 

more complex was his 'pigpen' cipher, in which twenty-five letters of the alphabet were placed 

in squares. Then an angle alone would represent a letter, the same angle with a dot another 

letter, the same angle with two dots still another. In some cases, cryptography was used only 

for a few crucial words in an otherwise 'clear' message, a method also favored by certain American officials." 

Of the :first cipher mentioned in the preceding extract, there is much more to be said. Perhaps Bakeless was limited by space considerations. In any case, I will leave that story for 

another time and place. As for the second cipher Bakeless mentions in the extract, I can give 

you the whole alphabet, for it exists among the Clinton Papers. 

A B C D E F G H I K L M N 0 P Q R S T U W X Y Z 

51 52 53 54 55 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 

There is no explanation why the sequence beginning with 50 stops with E-55 and then, 

starting with F-60 goes straight on without any break to Z-78. (Remember that in those 

days I and J were used interchangeably, as were U and V.) 

Finally, as to what Bakeless (and others) call the "pigpen" cipher, this is nothing but the 

hoary old so-called "Masonic" cipher based upon the 4-cross :figure 

=t==t= a- _j ...J c- .:_J 

which can accommodate 27 characters, not 25, as Bakeless indicates. Letters cari be inserted 

in the design in many different arrangements. 

I've mentioned that code or conventional names were used to represent the names of important persons and places in these American colonial and British cryptograms of the Revolution. Here are examples selected from a list of code names prepared by the famous British 

spy, Major Andre, chief of intelligence under General Clinton: 

For American Generals-the names of the Apostles, for instance: 

Names of Forts: 

Names of Cities: 

Names of Rivers and Bays: 

Miscellaneous: 

General Washington was James 

General Sullivan was Matthew 

Fort Wyoming-Sodom 

Fort Pitt-Gomorrha 

Philadelphia-Jerusalem 

Detroit-Alexandria 

Susquehanna-Jordan 

Delaware-Red Sea 

Indians-Pharisees 

Congress-Synagogue 

39 OONfi'fDENTIAL 
REF ID:A63860 

I'm sure you've learned as school children all about the treasonable conduct of Benedict 

Arnold when he was in command of the American Forces at West Point; but you probably 

don't know that practically all his exchanges of communications with Sir Henry Clinton, Commander of the British Forces in America, were in cipher or in invisible inks. One of Arnold's 

cipher messages, in which he offers to give up West Point for £20,000 is shown below, Fig. 

38a being the secret version, Fig. 386, the plain t.ext. Arnold left a few words en clair, the ones 

Figure 38a. Figure 386. 

he considered unimportant; for the important ones he used a dictionary as a codebook, indicating the page number, column number and line number corresponding to the position in the 

dictionary of the plaint.ext word which the code group represents. Arnold added 7 to these 

numbers, which accounts for the fact that the :first number in a code group is never less than 8, 

the central number is always either 8 or 9, and the third number is never less than 8 or more 

than 36. The significant sentence appears near the middle of the message: "If I 198-9-34, 

185-8-31 a 197-8-8 ... " yields the plain text: "If I point out a plan of cooperation by which 

S. H. (Sir Henry Clinton) shall possess himself of West Point, the Garrison, etc., etc., etc., 

twenty thousands pound Sterling I think will be a cheap purchase for an object of so much 

importance." The signature 172-9-19 probably stands for the word "Moor"; Arnold's code 

name in these communications was "John Moore." He had also another name, "Gustavus." 

I 

nl f•U, U~? n__,..,.._ 'f"'f'V'" ,fJ I 

.., ,,, ,. ,, ,,. • .,,, '"'" ~ ~qi ••• 

_,,,.,,. ....... 7.~,. .. ,.,~·S4~ 

l.lfl''·.L##r,,,,,, ~7•d:.td.'/-U 

,...,.,,. _...., '""·?·'"' ._;;,., •. ,.1.7 i IHo/•Po'·- I~" d',IL In 1 ~'4f~ 

Figure 39. 

40 
REF ID:A63860 

09NFEB1!1Nl'EAL 

Figure 39 is a message in which he gave the British information which might have led to the 

capture of his commander-in-chief, General Washington; the top shows the code message, the 

bottom the plain text. Arnold used the same additive as in the preceding example. Washington, however, was too smart to be ambushed-he went by a route other than the one he 

said he'd take. 

Figure 40. 

Sir 

W.Howe 

is gone to the 

Cheasapeak bay with 

the great.est part of the 

army. I hear he is DOW 

landed but am not 

certain. I am 

left to command 

here with a 

too small force 

to make any effectual 

divemion in your favor 

I shall try something cer 

At any rate It may be of use 

to you. I own to you I think. 

S! W's move just at this time 

the worst he could take 

much joy on your success 

You may find Fig. 40 int.eresting as an example of the special sort of mask or grille used by 

Arnold and by the British in their negotiations with him. The real or significant text is written in lines outlined by an hourglass figure and then dummy words are supplied to fill up the 

lines so that the entire letter apparently makes good sense. To read the secret message, you're 

supposed to have the same !ilize hourglass figure that was used to conceal the secret message. 

In Fig. 40 the left-hand portion shows the "phoney" message. Masks having small rectangular apertures were also used, the significant words being written so that they were disclosed 

when the mask was placed on the written message so as to isolate them from the non significant words. The significant text in this example is shown in printed form to the right of the 

original hourglass design. 

An int.eresting episode involving concealment of this sort is recorded by Bakeless. An urgent message from Sir Henry Clinton, dated 8 October 1777, and written on thin silk, was concealed in an oval silver ball, about the size of a ritle bullet, which was handed to Daniel Taylor, 

a young officer who had been promised promotion if he got through alive. The bullet was 

made of silver, so that the spy could swallow it without injury from corrosion ... Almost as 

soon as he started, Taylor was captured . . . Realizing his peril too late, the spy fell into a 

paroxysm of terror and, crying, "I am lost,'' swallowed the silver bullet. Administration of a 

strong emetic soon produced the bullet with fatal results, for Taylor was executed. "A rather 

heartless American joke went around,'' adds Bakeless, "that Taylor had been condemned 'out 

of his own mouth'." 

We next see (Fig. 41) one Benedict Arnold message that never was deciphered. It is often 

referred. to as "Benedict Arnold's Treasonable Cow Letter." Only one example is extant; 

certain words have purely arbitrary meanings, as prearranged. The letter was written just 

two weeks before the capture of Major Andre. 

In Fig. 42, we see a British cipher message of the vintage 1781. It was deciphered before 

finding the key, always a neat trick when or if you can do it. The key-the title page of the 

then current British Army List-is shown in Fig. 43. The numbers in the cipher text obvi41 
REF ID:A63860 

GQN¥HlBNHAL 

a .. ~ 

.l'..1"- /-~ -- ~-- -.J .:.-/ 

"-~.;::;::::,, ·'-" """'~' .~. ,,r.;..,, 

~;"•°"· ",./.,,:..,_,_A 41;,..:.:,,_. .. ..At 

"~/ ~+·" llf.,4._ ,. .. .J-e_,,./~Att. 

tt ..... "',JI,,,_ - ""'-"'7 ,. S(._..J? ;',r •• / 

r-.. :z-./,._ 'l--· ~- ,,,r,.. ""',,_,,.,. - ,(, '" 

~~.fl,.,..,,?,_.,~./~._.,,,,/~ 

.-7 ~.;·- ~ 7 :'-;...,..,"'?-· ') --r ~ c 1 • ,< • -"7,,,, ~.;... ,,,,. ,,..,..;._ .<: • .:. A.<-

. ~ ... .;, 4-?,... ... ~ .. ,,t:. • .) .... ,,,~ .:'_. 

~~ ~ --· Ho 7 ,~_.., .t/..-r-11 "°~4 

~ ,,,.,_,,tf.? ~¥~,­

./.._ 

~~~ "' ~ r-~·::.df'.t"~ .... · 

~ 

t/ld-..l'il 

Figure 41. 

........ ,1,11,, Sep. 11 

Figure 42. 

ously refer to line numbers and letter numbers in the line of a key text, the :first series of numbers, viz., 22.6.7.39.5.9.17, indicating line number 22, letter numbers 6.7.39.5.9.17 in that line. 

Because of so many repetitions, the plain text was obtained by straightforward analysis by an 

officer recently on duty in NSA, Captain Edward W. Knepper, USN, to whom I am indebted 

Ir Pii;u1u110" cl1M K1c11T Ho•uaa.a•S.• 

The S E c R r. T A ll Y at W A R. 

A 

L I s T Of THE 

GENERAL and HELD OFFICERS, 

As tl1cy rank 1n the Anny. 

OP T 11 E 

orrlCERS 1n the rcvcr'1 REGIMENTS 

or 

HORSE, DRAGOONS, and FOOT, IHI TRB 

BRITISH .. d IRl>H ESTABLISHMENTS. 

(Te.t.1•11 ....... 

A• Al.PHAllTICA• hD•X) 

'l'9 llepl &1c.1111wT el An11.L .. r. •• L .... -6 ••••••••It ... kU• AITll.l.HI' ........... .. 

A .. 61 MAKI oES m Pl.LL ... llAU' PAI' 

WITH 

TIK'Dmsof theirCOM:MllHOICI, ulhey rank 111eack 

ltlDllPe and'" the llll!ltJ. 

Tiii On••••••· Lt•vl'l•••T G•11••••· ac. et •11 llAJllTY'a G11•11••111tl ... u• A....,,wHdllr A1o,••••c11 • 

.1n*Orr1cH••H1uP1T1 A•• 

A SUCCEllSION of COLONELS, Wi ..... u ..................... ._ ...... o .... ... c ........... .... MDCCLXXYIU. 

l.ON00•1 

.~ ...... 1.11 ...... ., .... ~---.,..,in..w. 

Figure 43. 

42 

... 
.. 

REF ID:A63860 

CQHPIBENTIA£ 

for this interesting example. The plain text, once obtained, gave him clues as to what the key 

text might be, simply by placing the plaintext letters in their numerical-equivalent order in 

the putative key text. This done, Captain Knepper was quick to realize what the key text 

was-a British Army List. The date of the message enabled him to find the list without much 

difficulty in the Library of Congress (Fig. 43). 

There was an American who seems to have been the Revolution's one-man National Security 

Agency, for he was the one and only cryptologic expert Congress had, and, it is claimed, he 

managed to decipher nearly all, if not all, of the British code messages obtained in one way or 

another by the Americans. Of course, the chief way in which enemy messages could be obtained in those days was to capture couriers, knock them out or knock them off, and take the 

messages from them. This was very rough stuff, compared to getting the material by radio 

intercept, as we do nowadays. 

I think you'll be interested to hear a bit more about that one-man NSA. His name was 

James Lovell and besides being a self-trained cryptologist, he was also a member of the Continental Congress. There's on record a very interesting letter which he wrote to General 

Nathaniel Greene, with a copy to General Washington. Here it is. 

Philadelphia, Sept. 21, 1781 

Sir: 

You once sent some papers to Congress which no one about you could decyP.her. Should such 

be the Case with some you have lately forwarded I presume that the Result of my pains, here 

sent, will be useful to you. I took the Papers out of Congress, and I do not think it necessary 

to let it be known here what my success has been in the attempt. For it appears to me that 

the Enemy make only such Changes in their Cypher, when they meet with misfortune, as makes 

a difference of Position only to the same Alphabet, and therefore if no talk of Discovery is made 

by us here or by your Family, you may be in Chance to draw Benefit this Campaign from my 

last Night's Watching. 

I am Sir with much respect, 

Maj. Genl. Greene 

(With copy to Genl. Washington) 

Your Friend, 

JAMES LOVELL 

In telling you about Lovell I should add to my account of that interesting era in cryptologic 

history an episode I learned about only recently. When a certain message of one of the generals in command of a rather large force of Colonials came into Clinton's possession he sent it 

off posthaste to London for solution. Of course, Clinton knew it was going to take a lot of 

time for the message to get to London, be solved and returned to America-and he was naturally a bit impatient. He felt he couldn't afford to wait that long. Now it happened that in 

his command there were a couple of officers who fancied themselves to be cryptologists and 

they undertook to solve the message, a copy of which had been made before sending the original 

off to London. Well, they gave Sir Henry their solution and he acted upon it. The operation 

turned out to be a dismal failure, because the solution of the would-be cryptanalysts happened 

to be quite wrong! The record doesn't say what Clinton did to those two unfortunate cryptologists when the correct solution arrived from London some weeks later. By the way, you may 

be interested in learning that the British operated a regularly established cryptanalytic bureau as early as in the year 1630 and it continued to operate until the end of July 1844. Then 

there was no such establishment until World War I. I wish there were time to tell you some 

of the details of that fascinating and little known bit of British history. 

There's also an episode I learned about only very recently, which is so amusing I ought to 

share it with you. It seems that a certain British secret agent in America was sent a message 

in plain English, giving him instructions from his superior. But the poor fellow was illiterate 

and there wasn't anything to do but call upon the good offices of a friend to read it to him. 

He found such a friend, who read him his instructions. What he didn't know, however, was 

that the friend who'd helped him was one of General Washington's secret agents! 

43 
REF ID:A63860 

The next illustration (Fig. 44) is a picture of one of several syllabaries used by Thomas 

Jefferson. It is constructed on the so-called two-part principle, which was explained in the 

preceding lecture. Figure 44a is a portion of the encoding section, and Fig. 44b is a portion 

of the decoding section, in which the code equivalents are in numerical order accompanied by 

their meanings as assigned them in the encoding section. This sort of system, which, as I've 

already explained, was quite popular in Colonial times as in the early days of Italian cryptography, is still in extensive use in some parts of the world. 

Figure 44a. Figure 44b. 

A few minutes ago I mentioned Benjamin Franklin's cipher system, which, if used today, 

would be difficult to solve, especially if there were only a small amount of traffic in it. Let 

me show you what it was. Franklin took a rather lengthy passage from some book in French 

and numbered the letters successively. These numbers then became equivalents for the same 

letters in a message to be sent. Because the key passage was in good French, naturally there 

were many variants for the letter E-in fact, there were as many as one would expect in normal plaintext French; the same applied to the other high-frequency letters such as R, N, S, I, 

etc. What this means, of course, is that the high-frequency letters in the plain text of any 

message to be enciphered could be represented by many different numbers and a solution on 

the basis of frequency and repetitions would be very much hanpered by the presence of many 

variant values for the same plaintext letter. In Fig. 45 you can see this very clearly . 

. .,. .6. 'JO" ., IQ II ... s•o ·' 3~!J •' 

.,., .•. , lff .') .,., .., llOU 3M:>.1 

,,. .... ljslC 191 v :!/' 3••,,. 3•1' 

"' .,,. •9' .. 3•• ~ 3h ,. 

,, "°' 13JJ 

111111 •do, 3•.J I 3,J :· 

C% i•·J .... r. 

•11• " di ,. 3•• ,. 31+ I 

'::. f9 • IJI' .,,,z ... '() 311 :r 3M;; I 

... 71/' 13'•' llGJ ~- 3•'' 316 / .t: 137•• ICO 1" 

7+: 1311 •r ... I' 11114 '" 3•7 ,. 38~ 7S ' ,, ~OS IN 1165 3••. 3•K h U.J 76 .. 13g ,, IOJ; !!6ti ,, 32!1 ,, HJ' 77 #' 140 0 =Of~ 1167,.,. 3Hll I 

••• i IJO I .. ,. 39:1 I 71 .. •ts.t IDS l" .,. ,. 331 •• 14JI .,, i soll.:Z: •'11 'I 3!11, 

•• #. to., 143r I07, 1120'" 

3311 ~ 3v: /c 

I~ .... lff~ .. ., s7i 1' 3u', 3ll~ ' 

h~ 141 ~ •1•, I 33+ u i!I.\ • 

~· ~ •4'/ '°'' '· 131" 3115 I 

lit .... 147" ••o II- •73J u6 /11 2911 J,. -

Figure 45. 

44 
REF ID:A63860 

C6NFfBBN'ffAL 

I know of but one case in all our U. S. history in which a resolution of Congress was put out 

in cryptographic form. It is shown in Fig. 46-a resolution of the Revolutionary Congress 

dated 8 February 1782. I have in my collection not only a copy of the resolution but also a 

copy of the syllabary by which it can be deciphered. 

Interest in cryptology in America seems to have died with the passing of Jefferson and 

Franklin. But if interest in cryptology in America wasn't very great, if it existed at all after 

the Revolution, this was not the case in Europe. Books on the subject were written, not by 

professionals, perhaps, but by learned amateurs, and I think you will find some of them in the 

NSA library if you're interested in the history of the science. The next illustration (Fig. 47) 

is the frontispiece of a French book the title of which (translated) is "Counter-espionage, or 

keys for all secret communications." It was published in Paris in 1793. In the picture, we 

see Dr. Cryppy himself, and perhaps a breadboard model of a GS-11 research analyst, or maybe an early model of a WAC. 

,,,_.,,,.._.,~.:.,. 

~~::>4-;;....:l 

:).:h'°'A1nl~ 

J"f 

,,_;L.~a..j. •• 1 Cl < f .......,.. 

~":.-""~-..,- /"'~.¥-"':...-~ - ~~ -

~~-=- ~'t .. ~ - ~ .. :!;'!~~J".:Ju_---=:, 

~~~~~~-=- ~~ -:~::- ,,_ - "/= ..«.. -- 07 - &.6 - ~7- 46',. ow J.a'"' 

--·~ -"l'-.r--;:-- ...-.... :. - s7 __ ,,.., -P."'~"svll.•- -'(Jo- ; A. ., ci:j .,;. ,.,_ -..:>-fo--..C:- ,_,....__ 4.-

~.,, ~--•!I ; ht- .. ,._&l~N'- .I~- _,.,..c _ .--r.,,_ - ___ ,, --

~ :__A:;:-=-!''.:::--.:·-;::.::~~:...:..-

- _, _ 6- .:,:;·~"7 '~-"''" ~- ti!- ..... .:. - '-1'7-- _ .. -

~=- ~::_~;_'":-:.-:k-~~~ -- Y·- dfj..._.y..H- J' A•• "~ 

~ ~- --·· --- - ---,,. -- & 

ii - .,., ... ,_ "';-6 1.-- l'-r..a -/t-- ~ -· - N.J - .,;;;; ,,_ __ ~,.., J .. f - MJ'.- ,~:;_-..z.. - ·- - ,.,,.,..,,....,,_ ;: __ - .. _ -"~ 

.•1.1- .~ - ,,,,., -· ¥ 

,"Ii<• - .... __ _,_ n.a.- .J- -

Figure 46. 

I am now going to tell you something about the early steps in :finding an answer to the ageold mystery presented by Egyptian hieroglyphics, not only because I think that the solution 

represents the next landmark in the history of cryptology, but also because the story is of general interest to any aspiring cryptologist. About 1821 a Frenchman, Champollion, startled 

the world by beginning to publish translations of Egyptian hieroglyphics, although in the 

budding new :field of Egyptology much had already transpired and been published. In Fig. 

48 we see the gentleman and in Fig. 49, a picture of the great Napoleonic :find that certainly 

facilitated and perhaps made possible the solution of the Egyptian hieroglyphic writing-the 

Rosetta Stone. The Rosetta Stone was found in 1799 at Rashid, or, as the Europeans call it, 

Rosetta, a town in northern Egypt on the west bank of the Rosetta branch of the Nile. Rosetta was in the vicinity of Napoleon's operations which ended in disaster. When the peace 

treaty was written, Article 16 of it required that the Rosetta Stone, the significance of which 

45 
REF ID:A63860 

C~FIDENTmL 

was quickly understood by both the conquered French and victorious British commanders, be 

shipped to London, together with certain other large antiquities. The Rosetta Stone still 

occupies a prominent place in the important exhibits at the British Museum. The Rosetta 

Stone is a bilingual inscription, because it is in Egyptian and also Greek. The Egyptian portion consists of two parts, the upper one in hieroglyphic form, the lower one in a sort of cursive 

Figure 4'7. Figure 48. 

script, also Egyptian, but called "Demotic." It was soon realized that all three texts were 

supposed to say the same thing, of course, and since the Greek could easily be read, it served 

as something called in cryptanalysis a "crib." Any time you are lucky enough to find a crib 

it saves you hours of work. It was by means of this bilingual inscription that the Egyptian 

hieroglyphic writing was :finally solved, a feat which represented the successful solution to a 

problem the major part of which was linguistic in character. The cryptanalytic part of the 

task was relatively simple. Nevertheless, I think that anyone who aspires to become a professional cryptologist should have some idea as to what that cryptanalytic feat was, a feat 

which some professor (but not of cryptologic science; I think it was Professor Norbert Wiener, 

of the Massachusetts Institute of Technology) said was the greatest cryptanalytic feat in 

history. We shall see how wrong the good professor was, because I'm going to demonstrate 

just what the feat really amounted to by showing you some simple pictures. 

First, let me remind you that the Greek text served as an excellent crib for the solution of 

both Egyptian texts, the hieroglyphic and the Demotic, the latter merely being the conventional abbreviated and modified form of the Hieratic character or cursive form of hieroglyphic 

writing that was in use in the Ptolemaic Period. 

The initial step was taken by a Reverend Stephen Weston who made a translation of the 

Greek inscription, which he read in a paper delivered before the London Society of Anitquaries, 

in April 1802. 

In 1818 Dr. Thomas Young, the physicist who :first proposed the wave theory of light, compiled for the 4th volume of Encyclopa.edia Bri'tannica, published in 1819, the results of his 

studies on the Rosetta Stone and among them there was a list of several Egyptian characters 

to which, in most cases, he had assigned correct phonetic values. He was f:he first f,o grasp f:he 

idea of a phonetic principle in f:he Egyptian hieroglyphs and he was f:he first w apply it to f:heir decipherment. He also proved something which others had only suspected, namely, that the 

46 
REF ID:A63860 

CONnBl!JN'l'li.•a:L 

hieroglyphs in ovals or cartouches were royal names. But Young's name is not associated in 

the public mind with the decipherment of Egyptian hieroglyphics-that of Champollion is 

very much so. Yet much of what Champollion did was based upon Young's work. Perhaps 

the greatest credit should go to Champollion for recognizing the major importance of an ancient 

language known as Coptic as a bridge that could lead to the decipherment of the Egyptian 

hieroglyphics. As a lad of seven he'd made up his mind that. he'd solve the hieroglyphic 

writing, and in the early years of the 19th Century he began to study Coptic. In his studies 

of the Rosetta Stone his knowledge of Coptic, a language the knowledge of which had never 

been lost, enabled him to deduce the phonetic value of many syllabic signs and to assign correct readings to many pictorial characters, the meanings of which became known to him from 

the Greek text on the Stone. 

Figure 49. 

47 CONflBEN'i'IAL 
REF ID:A63860 

cornr:mEN'f'IAL 

The following step-by-step account of the solution is taken from a little brochure entitled 

The Rosetta Stone, published by the Trustees of the British Museum. It was written in 1922 

by E. A. Wallis Budge and was revised in 1950. I quote: 

"The method by which the greater part of the Egyptian alphabet was recovered is this: It 

was assumed correctly that oval ~ , or "cartouche" as it is called, always contained a 

royal name. There is only one cartouche (repeated six times with slight modifications) on the 

Rosetta Stone, and this was assumed to contain the name of Ptolemy, because it was certain 

from the Greek text that the inscription concerned a Ptolemy. It was also assumed that if 

the cartouche did contain the name of Ptolemy, the characters in it would have the sounds of 

the Greek letters, and that all together they would represent the Greek form of the name of 

Ptolemy. Now on the obelisk which a certain Mr. Banks had brought from Philae there was 

also an inscription in two languages, Egyptian and Greek. In the Greek portion of it two 

royal names are mentioned, that is to say, Ptolemy and Cleopatra, and on the second face of 

the obelisk there are two cartouches, which occur close together, and are filled with hieroglyphs 

which, it was assumed, formed the Egyptian equivalents of these names. When these cartouches were compared with the cartouche on the Rosetta Stone it was found that one of them 

contained hieroglyphic characters that were almost identical with those which filled the cartouche on the Rosetta Stone. Thus there was good reason to believe that the cartouche on 

the Rosetta Stone contained the name of Ptolemy written in hieroglyphic characters. The 

fQPDS of the cartouches are as follows: 

On the Rosetta Stone:- c---~ -.,,-~--:-Q-:--:Q P::--:::T--::-3_-""=--a l-~ ]J 

On the Obelisk from Philae:- ( ~ f1 ~ QQ r f 3 ~ l JE:I) 

In the second of these cartouches a single sign takes the place of three signs at the end of the 

first cartouche. Now it has already been said that the name of Cleopatra was found in Greek 

on the Philae Obelisk, and the cartouche which was assumed to contain the Egyptian equivalent to this name appears in this form: 

c-~-Qf1-a-~-~-~-~J 

Taking the cartouches which were supposed to contain the names of Ptolemy and Cleopatra 

from the Philae Obelisk, and numbering the signs we have: 

Ptolemy, A. d;; afl.ib.~aQQ 1paSf •"'! ~g.:; 1a~ ~) 

Cleopatra, B. ( ~ .k ~Q 4f1 6•1\ c:b. 6 91& :: ~ ) 

Now we see at a glance that No. 1 in A and No. 5 in B are identical, and judging only by their 

position in the names they must represent the letter P. No. 4: in A and No. 2 in Bare identical, and arguing as before from their position, they must represent the letter L. As Lis the 

second letter in the name of Cleopatra, sign No. 1 in B must represent K. In the cartouche of 

Cleopatra, we now know the values of Signs Nos. 1, 2 and 5, so we may write them down thus: 

( K L aq •f1 P 11& cb. ~ u~ :~~) 

In the Greek form of the name of Cleopatra there are two vowels between the L and P, and 

in the hieroglyphic form there are two hieroglyphs, this ~ and this f] , so we may assume 

that the first is E and the other 0. In some forms of the cartouche of Cleopatra, No. 7 (the 

hand) is replaced by a half circle, which is identical with No. 2 in A and No. 10 in B. As T 

follows P in the name Ptolemy, and as there is a T in the Greek form of the name of Cleopatra, 

we may assume that the half circle and the hand have substantially the same sound, and that 

that sound is T. In the Greek form of the name Cleopatra there are two A's, the position of 

which agree with No. 6 and No. 9, and we may assume that the bird has the value of A. Substituting these values for the hieroglyphs in B we may write it thus: 

48 
REF ID:A63860 

CONMBBN't'fAL 

CK L B 0 p A T ~A ~ ~] 

Thomas Young noticed that the two signs o and C) always followed the name of a goddess, or 

queen, or princess. Other early decipherers regarded the two signs as a mere feminine termination. The only sign for which we have no phonetic equivalent is No. 8, the lens, and it is obvious 

that this must represent R. Inserting this value in the cartouche we have the name Cleopatra deciphered. Applying now the values which we have learned from the cartouche of Cleopatra to the cartouche of Ptolemy, we may write it thus: 

(r T 0 L ~ 6 ~~ 1 r Hf- 9~ 1::. P T n l ~] 

We now see that the cartouche must be that of Ptolemy, but it is also clear that there must be 

contained in it many other hieroglyphs which do not form part of his name. Other forms of 

the cartouche of Ptolemy are found, even on the stone, the simplest of them written thus: 

c ~fL~ ~~ r) .Q_ :i- tn 11,12 8 II 

It was therefore evident that these other signs 8 I u r ~a o 13 JI. •-• were royal titles corresponding to those found in the Greek text on the Rosetta Stone meaning "ever-living, beloved 

of Ptah." Now the Greek form of the name Ptolemy, i.e. Ptolemaios, ends with S. We may 

assume therefore that the last sign r in the simplest form of the cartouche given above has the 

phonetic value of S. The only hieroglyphs now doubtful are c:::::. and 9 9. , and their position in the name of Ptolemy suggests that their phonetic values must be M and some vowel 

sound in which the I sound predominates. These values, which were arrived at by guessing 

and deduction, were applied by the early decipherers to other cartouches, e.g.: 

1( a~~~~·=<~) 2(~~r~=~J Now in No. 1, we can at once write down the values of all the signs, viz., P. I. L. A. T. R. 

A., which is obviously the Greek name Philotera. In No. 2 we know only some of the hieroglyphs, and we write the cartouche thus: c..-A-L-~--S-~-. ___ T_R ___ )

It was known that the running-water sign IVVWIA occurs in the name Berenice, and that it represents N, and that this sign--++-- is the last word of the transcript of the Greek title "Kaisaros," and therefore represent some S sound. Some of the forms of the cartouche of Cleopatra begin with ( ~), and it is clear that its phonetic value must be K. Inserting these 

values in the cartouche above we have: c A_L_K_S---:~-N-T_R_S) 

which is clearly meant to represent the name "Alexandros," or Alexander. The position of 

this sign cq ) shows that it represented some sound of E or A. 

Well, I've showed you enough to make fairly clear what the problem was and how it was 

solved. As you may already have gathered, the cryptanalysis was of a very simple variety. 

The grammar?-Well, that's an entirely different story: There's where the difficult part 

lay. It was very fortunate that the first attacks on Egyptian hieroglyphics didn't have to 

deal with enciphered writing. Yes, the Egyptians also used cryptography; yes, there are 

"cryptographic hieroglyphics!" We'll get to these later, but at this point it may be of interest 

to many of you to learn something about what the Rosetta Stone had to say, as set forth by 

Dr. Budge: 

"The opening lines are filled with a list of the titles of Ptolemy V, and a series of epithets which 

proclaim the king's piety towards the gods, and his love for the Egyptians and his country. In 

the second section of the inscription the priests enumerate the benefits which he had conferred 

upon Egypt, and which may be thus summarized: 

1. Gifts of money and corn to the temples. 

2. Gifts of endowments to temples. 

49 
REF ID:A63860 

GOHPIBBlffIAL 

3. Remission of taxes due to the Crown. 

4. Forgiveness of debts owed by the people to the Crown. 

7. Reduction of fees payable by candidates for the priesthood. 

8. Reduction of the dues payable by the temples to the Crown. 

13. Forgiveness of the debts owed by the priests to the Crown. 

14. Reduction of the tax on byssus (a kind of flax or cotton fibre). 

15. Reduction of the tax on com lands. 

I t '~ •• ~ _, - .... 

\. 

..., . ( . . ,· .... "'.I 

Figure 50a. 

50 
REF ID:A63860 

GONFIBBN I 12\'.L 

Figure oOb. 

Could it be that installment-plan buying was rampant in Ancient Egypt too, so that people 

didn't have enough left to pay their taxes? 

Now, let's go back to those cryptographic hieroglyphics mentioned a moment ago. Here, 

in Fig. 50a for instance, is a picture of an inscription on a stela now in the Louvre, in Paris. 

Lines 6-10, inclusive, below the seated :figures under the arch, contain secret writing in hieroglyphics; in Fig. 50b, these lines are seen enlarged. I won't attempt to explain the nature-of 

the cryptography involved. It's pretty simple-something like the sort of cryptography involved in our own type of rebuses, and in our modern acronymic abbreviations, such as CARE, 

which stands for Cooperative (for) American Relief Everywhere, or NASA, for the National 

Aeronautics (and) Space Administration. 

The following extracts, translated from a long article by Prof. Etienne Drioton in "Revue 

D'Egyptologie,'' Paris, 1933, will be of int.erest (p. 1): 

"From the time of the Middle Empire onwards, Egypt had, alongside the official and normal 

system of writing, a tradition of cryptographic writing, the oldest known examples of which are 

to be found in the tombs of Beni-Hassan, and the most recent in the inscriptions of the temples 

of the Greco-Roman epoch. 

* • * * * • * 

(p. 32): 

It ie necessary to add to the enumeration of the cryptographic procedures the variation in the 

appearance of the cryptographic signs themselves . . . . Thie variation, without however affecting their value, can (1) modify the appearance of the signs; (2) affect their position in various 

ways; and (3) combine these signs with others. . .. Finally, to note a last peculiarity of these 

inscriptions which, because of their :fine form, deserve to be considered the classics of the cryptography of this 'period, the scribe has several times successfully carried out in them what was 

doubtless considered to be the triumph of the genre: the grouping of signs which offer a possible 

but fallacious meaning in clear, alongside a cryptographic meaning which ie the only true one." 

• * * * * * * 

And now for the most intriguing explanation offered by Drioton as to why cryptography was 

incorporated in these inscriptions. You know quit.e well why cryptography is employed in 

military, diplomatic, banking, and industrial affairs; you also know perhaps that it is used for 

other purposes, in love affairs, for example, and in illicit ent.erprises of all sorts; and you probably also know that it is oft.en used for purposes of amusement and diversion, in tales of myst.ery, in the sorts of things published in newspapers and lit.erary journals-they are called 

"crypts." But none of these explanations will do for the employment of cryptography in 

Egyptian hieroglyphics. Here's what Drioton thinks: 

51 
REF ID:A63860 

CONFf:Bl!JN'l'IAI. 

(p. 50): 

"There remains, therefore, the supposition that, far from seeking to prevent reading, the 

cryptography in certain passages of these inscriptions was intended to encourage their reading. 

The appeals which often introduce formulae of this type, and which are addressed to all visitors to the tombs, show in fact how much the Egyptians desired to have them read, but also, by 

the very fact of their existence, what an obstacle they encountered in the indifference, not to say 

satiety, produced by the repetition and the monotony of these formulae. To attempt to overcome this indifference by offering a text whose appearance would pique curiosity, based on the 

love, traditional in Egypt, for puzzles, to get people to decipher, with great difficulty, what was 

desired they should read, such is perhaps, in last analysis, the reason why the three monuments 

of the period of Amenophis III here considered present certain passages in cryptography. 

One must suppose, in this case, that the goal was not attained and that it was very quickly 

seen that the expedient produced, on the apathy of the visitors, an effect opposite to that intended: it removed even the slightest desire to read the inscriptions presented in this form. The 

new procedure was therefore---the monuments seem to prove it-abandoned as soon as it had 

been tried." 

• * * • • * • 

Before leaving the story of Champollion's mastery of Egyptian hieroglyphic writing, I think 

I should re-enact for you as best I can in words what he did when he felt he'd really reached 

the solution to the mystery. I'll preface it by recalling to you what Archimedes is alleged to 

have done when he solved a problem he'd been struggling with for some time. Archimedes 

was enjoying the pleasures of his bath and was just stepping out of the pool when the solution 

of the problem came to him like a :flash. He was so overjoyed that he ran, naked, through the 

streets shouting "Eureka! I've found it, I've found it." Well, likewise, when young Champollion one day had concluded he'd solved the mystery of the Egyptian heiroglyphics, he set 

out on a quick mile-run to the building where his lawyer brother worked, stumbled into his 

brother's office, shouting "Eugene, I did it!", and flopped down to the floor in a trance where 

he is said to have remained immobile and completely out for five days. "Champollion died 

on 4 March 1832, leaving behind the manuscript of an Egyptian Grammar and of a Hieroglyphic Dictionary which, except for some errors of details inevitable in a gigantic work of decipherment and easily correctable, form the basis of the entire science of Egyptology." 1 

I shouldn't leave this brief story of the cryptanalytic phases of the solution of the Egyptian 

hieroglyphic writing without telling you that there remain plenty of other sorts of writings 

which some of you may want to try your hand at deciphering when you've learned some of the 

principles and procedures of the science of cryptology. A list of thus-far undeciphered writings was drawn up for me by Professor Alan C. Ross, of London University, in 1945, and had 

19 of them. Since 1945 only two have been deciphered, Minoan Linear A and Linear B writing. The Easter Island writing is said to have very recently been solved, but I'm not sure of 

that. There are some, maybe just a very few, who think the hieroglyphic writing of the 

ancient Maya Indians of Central America may fall soon, but don't be too sanguine about that 

either. 

Should any of you be persuaded to tackle any of the still undeciphered writings in the list 

drawn up by Professor Ross, be sure you have an authentic case of an undeciphered language 

before you. Figure 16 is one that was written on a parchment known as the Michigan Papyrus. It had ba:fB.ed certain savants who had a knowledge of Egyptology and attempted to 

read it on the theory that it was some sort of variation-a much later modification-of Egyptian hieroglyphic writing. These old chaps gave it up as a bad job. Not too many years ago, 

it came to the attention of a young man who knew very little about Egyptian hieroglyphics. 

He saw it only as a simple substitution cipher on some old language. He tackled the Michigan Papyrus on that basis and .solved it. He found the language to be early Greek. And 

what was the purport of the writing? Well, it was a wonderful old Greek beautician's secret 

formula for further beautifying lovely Greek young women-maybe the bathing beauties of 

those days, among whom possibly were "Miss Greece of 500 B. C." and "Miss Universe" of 

those days! 

1 Drioton, "Decipherment of Egyptian Hiooglyphics," La Science Modeme, August 1924, pp. 423-432. 

52 
$ f<- -,,.._... - - ..J# .- --

••>----- ¥=" --· 

~ --

~--- --

--~ __ :.--

REF ID:A63860 

C6N.FfBfiN'l'I1Y:. 

Figure 51. 

The next period of importance in this brief account of the history of cryptology is the one 

which deals with the codes and ciphers used by the contestants in our Civil War, the period 

1861-65. It is significant and important because, for the first time in history, rapid and secure 

communications on a large scale became practicable in the conduct of organized warfare and 

world-wide diplomacy. They became practicable when cryptology and telegraphy were joined 

in happy, sometimes contentious, but long-lasting wedlock. 

There is one person I should mention, however, before coming to the period of the Civil War 

in U.S. history. I refer here to Edgar Allan Poe, who in 1842 or thereabouts, kindled an interest in cryptography in newspapers and journals of the period, both at home and abroad. 

For his day he was certainly the best informed person in this country on cryptologic matters 

outside of the regular employees of Government departments interested in the subject. 

In regard to Poe, one of our early columnists, there's an incident I'd like to tell you about 

in connection with a challenge he printed in one of his columns, in which he offered to solve any 

cipher submitted by his readers. He placed some limitations on his challenge, which amounted 

to this-that the challenge messages should involve but a single alphabet. In a later article 

Poe tells about the numerous challenge messages sent him and says: "Out of perhaps 100 

ciphers altogether received, there was only one which we did not immediately succeed in resolving. This one we demonstrated to be an imposition-that is to say, we fully proved it a 

jargon of random characters, having no meaning whatever." I wish that cipher had been 

preserved for posterity, because it would be interesting to see what there was about it that 

warranted Poe to state that "we fully proved it a jargon of random characters." Maybe I'm 

not warranted in saying of this episode that Poe reminds me of a ditty sung by a character in 

a play put on by some undergraduates of one of the colleges of Cambridge University, in England. At a certain point in the play, this character steps to the front of the stage and sings: 

"I am the Master of the College, 

What I don't know ain't knowledge." 

53 
REF ID:A63860 

OON.PIBBN'ffAL 

Thus, Poe. What he couldn't solve, he assumed wasn't a real cipher-a very easy out for any 

cryptologist up against something tough. 

If any of you are interested sufficiently to wish to learn something about Poe's contributions 

to cryptology, I refer you to a very fine article by Professor W. K. Wimsatt, Jr., entitled "What 

Poe Knew About Cryptography," Publications of the Modern Language Association of America, New York, Vol. LVIII, No. 3, September 1943, pp 754-79. In it you'll find references to 

what I have published on the same subject. 

This completes the third lecture in this series. In the next one we shall come to that interesting period in cryptologic history in which codes and ciphers were used in this country in the 

War of the Rebellion, the War Between the States, the Civil War-you use your own pet 

designation for that terrible and costly struggle. 

54 
REF ID:A63860 

Lecture IV 

A detailed account of the codes and ciphers of the Civil War in the United States of America 

can hardly be told without beginning with a bit of biography about the man who became the 

:first signal officer in history and the :first Chief Signal Officer of the United States Army, Albert 

J. Myer, the man in whose memory that lovely little U.S. Army post adjacent to Arlington 

BRffiAf\TF.H GC::-.U:,\L Al.131.ffl' .I '.\l'i I· n 

Figure 52. 

Cemetery was named. Myer was born on 20 September 1827, and after an apprenticeship in 

the then quite new science of electric telegraphy he entered Hobart College, Geneva, New York, 

from which he was graduated in 1847. From early youth he had exhibited a predilection for 

artistic and scientific studies, and upon leaving Hobart he entered Buffalo Medical College, receiving the M.D. de~ree four years later. His graduation thesis, "A Sign Language for Deaf 

Mutes," contained the germ of the idea he was to develop several years later, when, in 1854, 

he was commissioned a 1st Lieutenant in the Regular Army, made an Assistant Surgeon, and 

ordered to New Mexico for duty. He had plenty of time at this far away outpost to think 

about developing an efficient system of military "aerial telegraphy," which was what visual 

signaling was then called. I emphasize the word "system" because, strange to say, although 

instances of the use of lights and other visual signals can be found throughout the history of 

warfare, and their use between ships at sea had been practiced by mariners for centuries, yet 

down to the middle of the 19th Century surprisingly little progress had been made in developing methods and instruments for the syst,ematic exchange of military information and instructions by means of signals of any kind. Morse's practical system of electric telegraphy, developed in the years 1832-35, served to focus attention within the military upon systems and 

methods of intercommunication by means of both visual and electrical signals. In the years 

55 
REF ID:A63860 

immediately preceding the Civil War, the U.S. Army took steps to introduce and to develop 

a system of visual signaling for general use in the :field. It was Assistant Surgeon Myer who 

furnished the initiative in this matter. 

In 1856, two years after he was commissioned assistant surgeon, Myer drafted a memorandum on a new system of visual signaling and obtained a patent on it. Two years later, a 

board was appointed by the War Department to study Myer's system. It is int.eresting to 

note that one of the officers who served as an assistant to Myer in demonstrating his system 

before the board was a Lieutenant E. P. Alexander, Corps of Engineers. We shall hear more 

about him presently, but at the moment I will say that on the outbreak of war, Alexander 

organized the Confederate Signal Corps. After some successful demonstrations by Myer and 

his assistants, the War Department fost.ered a bill in Congress, which gave its approval to his 

ideas. But what is more to the point, Congress appropriated an initial amount of $2,000 to 

enable the Army and the War Department to develop the system. The money, as stated in 

the Act was to be used "for manufacture or purchase of apparatus and equipment for :field 

signaling." The act also contained another important provision: it authorized the appointment, 

on the Army staff, of one Signal Officer with the rank, pay, and allowances of a major of cavalry. On 2 July 1860, "Assistant Surgeon Albert J. Myer (was appointed) to be Signal Officer, with the rank of Major, 27 June 1860, to fill an original vacancy," and two weeks later 

Major Myer was ordeied to report to the Commanding General of the Department of New 

Mexico for signaling duty. The War Department also directed that two officers be detailed 

as his assistants. During a several months' campaign against hostile Navajos, an extensive 

test of Myer's new system, using both :flags and torches, was conducted with much success. 

In October 1860, a Lieutenant J.E. B. Stuart, later to become famous as a Confederate cavalry leader, tendered his services to aid in signal instruction. 

Less than a year after Major Myer was appointed as the first and, at that time, the only 

Signal Officer of the U. S. Army, Fort Sumter was attacked and, after a 36-hour bombardment, 

surrendered. The bloody four-year war between the North and the South began. The date 

was 14 April 1861. Myer's system of aerial telegraphy was soon to undergo its real baptism 

under fire, rather than by fire. But with the outbreak of war, another new system of military 

signal communication, signaling by the electric telegraph, began to undergo its first thorough 

test in combat operations. This in itself is very important in the history of cryptology. But 

far more significant in that history is a fact that I mentioned at the close of the last lecture, 

uiz, that for the :first time in the conduct of organized warfare, rapid and secret milita.ry communications on a large scale became practicable, because cryptology and electric telegraphy were 

now to be joined in a lasting wedlock. For when the war began, the electric telegraph had 

been in use for less than a quarter of a century. Although the :first use of electric telegraphy in 

military operations was in the Crimean War in Europe (1854-56), its employment was restricted to communications exchanged among headquarters of the Allies, and some observers 

were very doubtful about its utility even for this limited usage. It may also be noted that in 

the annals of that war there is no record of the employment of electric telegraphy together with 

means for protecting the messages against their interception and solution by the enemy. 

On the Union side in the Civil War, military signal operations began with Major Myer's 

arrival in Washington on 3 June 1861. His basic equipment consisted of kits containing a 

white :flag with a red square in the center for use against a dark background; a red :flag with a 

white square for use against a light background; and torches for night use. It is interesting 

to note that these are the elements which make up the familiar insignia of our Army Signal 

Corps. The most pressing need which faced Major Myer was to get officers and men detailed 

to him wherever signals might be required, and to train them in what had come to be called 

the "wigwag system," 1 the motions of which are depicted in Fig. 53. This training included 

learning something about codes and ciphers and gaining experience in their usages. 

1 And, of course, the G. I.'s of those days had a pet name for the users of the system. They called them 

'':flag :floppers.'' 

CONPIBRN'f'IAL 56 
• 

REF ID:A63860 

But there was still no such separate entity as a Signal Corps of the Army. Officers and enlisted men were merely detailed for service with Major Myer for signaling duty. It was not 

until two years after the war started that the Signal Corps was officially established and organized as a separate branch of the Army, by appropriate Congressional action. 

In the meantime, another signaling organization was coming into being-an organization 

which was an outgrowth of the government's taking over control of the commercial telegraph 

companies in the United States on 25 February 1862. There were then only three in number: 

First Position First l.fotion - "One·· - "l"' 

Second Motion -·Two ·2 "One Two"- ·12·· 

·---~ . . . --~ ., 

·Two - One -Two - One" - "2121" "Three·-··3· or"Fron1·· 

Figure 53. 

57 
REF ID:A63860 

CONflBHN'flAL 

the American, the Western Union, and the Southwestern. The telegraph lines generally followed the right-of-way of the railroads. The then Secretary of War, Simon Cameron, sought 

the aid of Thomas A. Scott, of the Pennsylvania Railroad, who brought some of his men to 

Washington for railroad and telegraphic duties with tpe Federal Government. From a nucleus 

of four young telegraph operators grew a rather large military telegraph organization which 

was not given formal status until on 28 October 1861 President Lincoln gave Secretary Cameron authority to set up a "U. S. Military Telegraph Department" under a man named Anson 

Stager, who, as general superintendent of the Western Union, was called to Washington, commissioned a captain (later a colonel) in the Quartermaster Corps, and made superintendent of 

the Military Telegraph Department. Only about a dozen of the members of the Department 

became commissioned officers, and they were made officers so that they could receive and disburse funds and property; all the rest were civilians. The U.S. Military Telegraph "Corps," 

as it soon came to be designated, without warrant, was technically under Quartermaster General Meigs, but for all practical purposes it was under the immediate and direct control of the 

Secretary of War, a situation admittedly acceptable to Meigs. There were now two organizations for signaling in the Army, and it was hardly to be expected that no difficulties would 

ensue from the duality. In fact, the difficulties began very soon, as can be noted in the following extract from a lecture before the Washington Civil War Round Table, early in 1954, 

by Dr. George R. Thompson, Chief of the Historical Division of the Office of the Chief Signal 

Officer of the U.S. Army: 

The first need for military signals arose at the important Federal fortress in the lower Chesapeake Bay at Fort Monroe. Early in June, Myer arrived there, obtained a detail of officers and 

men and began schooling them. Soon his pupils were wig-wagging messages from a small boat, 

directing fire of Union batteries located on an islet in Hampton Roads against Confederate fortifications near Norfolk. Very soon, too, Myer began encountering trouble with commercial 

wire telegraphers in the area. General Ben Butler, commanding the Federal Department in 

southeast Virginia, ordered that wire telegraph facilities and their civilian workers be placed under the signal officer. The civilians, proud and jealous of their skills in electrical magic, objected 

in no uncertain terms and shortly an order arrived from the Secretary of War himself who countermanded Butler's instructions. The A:rmy signal officer was to keep hands off the civilian telegraph even when it served the Army. 

I have purposely selected this extract from Dr. Thompson's presentation because in it we 

can clearly hear the first rumblings of that lengthy and acrimonious feud between two signaling 

organizations whose uncoordinated operations and rivalry greatly reduced the efficiency of all 

signaling operations of the Federal Army. As already indicated, one of these organizations 

was the U.S. Military Telegraph "Corps," hereinafter abbreviated as the USMTC, a civilian 

organization which operated the existing commercial telegraph systems for the War Department, under the direct supervision of the Secretary of War, Edwin M. Stanton. The other 

organization was, of course, the infant Signal Corps of the United States Army, which was not 

yet even established as a separate Branch, whereas the USMTC had been established in October 

1861, as noted above. Indeed, the Signal Corps had to wait until March 1863, two years after 

the outbreak of war, before being established officially. In this connection it should be noted 

that the Confederate Signal Corps had been established a full year earlier, in April 1862. Until then, as I've said before, for signaling duty on both sides, there were only officers who were 

individually and specifically detailed for such duty from other branches of the respective 

Armies of the North and the South. Trouble between the USMTC and the Signal Corps of 

the Union Army began when the Signal Corps became interested in signaling by electric telegraphy and began to acquire facilities therefor. 

As early as in June 1861, Chief Signal Officer Myer had initiated action toward acquiring or 

obtaining electrical telegraph facilities for use in the field, but with one exception nothing 

happened. The exception was in the case of the episode in the military department in southeast Virginia, commanded by General Benjamin Butler, an episode that clearly foreshadowed 

the future road for the Signal Corps in regard to electrical signaling: the road was to be closed 

and barred. In August 1861, Colonel Myer tried again and in November of the same year he 

58 
REF ID:A63860 

e6NHBEN'f'IA:Ei 

recommended in his annual report that $30,000 be appropriated to establish an electric signaling branch in the Signal Corps. The proposal failed to meet the approval of the Secretary of 

Wa:r. One telegraph train, however, which had been ordered by Myer many months before, 

was delivered in January 1862. The train was tried out in an experimental fashion, and under 

considerable difficulties, the most disheartening of which was the active opposition of persons 

in Washington, particularly the Secretary of War. So, for practically the whole of the first 

two years of the war, signal officers on the Northern side had neither electrical telegraph facilities nor Morse operators-they had to rely entirely on the wig-wag system. However, by 

the middle of 1863 there were thirty ":flying telegraph" trains in use in the Federal Army. 

Here's a picture of such a train. The normal length of :field telegraph lines was five to eight 

miles, though in some cases the instruments had worked at distances as great as twenty miles. 

But even before the Signal Corps began to acquire these facilities, there had been agitation to 

have them, as well as their Signal Corps operating personnel, all turned over to the USMTC, 

which had grown into a tightly knit organization of over 1,000 men and had become very influential in Washington, especially by virtue of its support from Secretary of War Stanton. 

As a consequence, the USMTC had its way. In the fall of 1863, it took over all the electric 

telegraph facilities and telegraph operators of the Signal Corps. Colonel Myer sadly wrote: 

"With the loss of its electric lines the Signal Corps was crippled." 

A drawing from Myer's Manual of Signals illustrating the field, or B.ying, telegraph. It shows 

the wagon with batteries and instruments. The wire (in this case presumably bare copper, 

since it is being strung on insulators on poles) is being run out from a reel carried by two men. 

The linesmen are using a crowbar to open holes to receive the lance poles. Myer estimated that 2~ miles of such wire line could be put up in an hour. 

Figure 54. 

So now there were two competing signal organizations on the Northern side: The U. S. 

Army's Signal Corps, which was composed entirely of military personnel with no electric telegraph facilities (but was equipped with means for visual signaling), and the USMTC, which 

was not a part of the Army, being staffed almost entirely with civilians, and which had electric 

telegraph facilities and skilled Morse operators (but no means or responsibilj.ties for visual signaling or "aerial telegraphy" which, of course, was old stuff). "Electric telegraphy" was now 

the thing. The USMTC had no desire to share electric telegraphy with the Signal Corps, a 

determination in which it was most ably assisted by Secretary of War Stanton, for reasons that 

fall outside the scope of the present lecture. 

59 
REF ID:A63860 

CONWDEN 112\L 

However, from a technical point of view it is worth going into this rivalry just a bit, if only 

to note that the personnel of both organizations, the military and the civilian, were not merely 

signalmen and telegraph operators: they served also as cryptographers and were therefore entrusted with the necessary cipher books and cipher keys. Because of this, they naturally 

became privy to the important secrets conveyed in cryptographic communications and they 

therefore enjoyed status as VIP's. This was particularly true of members of the USMTC, 

because they, and only they, were authorized to be custodians and user8 of the cipher books. 

Not even the commanders of the units they served had access to them. For instance, on the 

one and only occasion when General Grant forced his cipher operator, a civilian named Beckwith, to turn over the current cipher book to a colonel on Grant's staff, Beckwith was immediately discharged by the Secretary of War and Grant was reprimanded. A few days later, 

Grant apologized and Beckwith was restored to his position. But Grant never again demanded the cipher book held by his telegraph operator. 

The Grant-Beckwith affair alone is sufficient to indicate the lengths to which Secretary of 

War Stanton went to retain control over the USMTC, including its cipher operators, and its 

cipher books. In fact, so strong a position did he take that on 10 November 1863, following a 

disagreement over who should operate and control all the military telegraph lines, Myer, by 

then full Colonel, and bearing the imposing title "Chief Signal Officer of the United States 

Army," a title he had enjoyed for only two months, was peremptorily relieved from that position and put on the shelf. Not long afterward, and for a similar reason, Myer's successor, 

Lieutenant Colonel Nicodemus, was likewise summarily relieved as Chief Signal Officer by 

Secretary Stanton; indeed, he was not only removed from that position-he was "dismissed from 

the Service." Stanton gave "phoney" reasons for dismissing Colonel Nicodemus, but I am 

glad to say that the latter was restored his commission in March 1865, by direction of the 

President; also by direction of the President, Colonel Myer was restored to his position as 

Chief Signal Officer of the U. S. Army on 25 February 1867. 

When Colonel Myer was relieved from duty as Chief Signal Officer in November 1863, he 

was ordered to Cairo, Illinois, to await orders for a new assignment. Very soon thereafter he 

was either designated (or he may have himself decided) to prepare a field manual on signaling 

and there soon appeared, with a prefatory note dated January 1864, a pamphlet of 148 pages, 

a copy of which is now in the Rare Book Room of the Library of Congress. The title page reads 

as follows: 

"A Manual of Signals: for the use of signal officers in the field. By Col. Albert J. Myer, Signal 

Officer of the Army, Washington, D. C., 1864." 

Even in this first edition, printed on an Army press, Myer devoted nine pages to a reprint of 

an article from Harper's Weekly entitled "Curiosities of Cipher," and in the second edition, 

1866, he expanded the section on cryptography to sixty pages. More editions followed and I 

think we may well say that Myer's Manual, in its several editions, was the pioneer American 

text on military signaling. But I'm sorry to say that as regards cryptology it was rather a 

poor thing. Poe had done better twenty years before that in his essay entitled "A few words 

on secret writing." 

Because of its historic nature, you may like to see what Myer's original "wig-wag code" was 

like. It was called "a two-element code" because it employed only two digits, 1 and 2, in 

permutations of 1, 2, 3 and 4 groups. For example, A was represented by the permutation 

22; B, by 2122; and C, by 121, etc. In :flag signaling, a "l" was indicated by a motion to the 

left, and a "2" by a motion to the right. Later these motions were reversed, for reasons which 

must have been good but are now not obvious. 2 Here is Myer's two-element code which continued to be used until 1912: 

1 This reversal can be seen in Fig. 53. 

OONflBBN'f'lltL 60 
A - 22 

B - 2122 

c - 121 

D- 222 

E - 12 

F - 2221 

G - 2211 

H - 122 

I - 1 

J - 1122 

K - 2121 

L - 221 

REF ID:A63860 

M - 1221 

N - 11 

0 - 21 

p - 1212 

Q - 1211 

R - 211 

s - 212 

T - 2 

u - 112 

v - 1222 

w - 1121 

x - 2122 

y - 111 

z - 2222 

& - 1111 

ing - 2212 

tion - 1112 

End of word - 3 

End of sentence - 33 

End of message - 333 

C6NPfMN'flAL 

Affirmative - 22.22.22.3 

Repeat - 121.121.121 

Error - 212121 

Note: No. 3 (end of word) was made by a forward downward motion, called "front." 

There were about a dozen more signals, for numerals, for frequently used short 

sentences, etc. 

We must turn our attention now to the situation as regards the organization for signaling 

in the Confederate Army. It is of considerable interest to note that in the first great engagement of the War, that of the first Bull Run battle, the Confederate Signal Officer was that 

young Lieutenant, E. P. Alexander, who had assisted in demonstrating the wig-wag system 

before a board appointed by the War Department to study Myer's system. Alexander, now 

a Captain in grey, used Myer's system during the battle, which ended in disaster for the Union 

forces; and it is said that Alexander's contribution by effective signaling was an important 

factor in the Confederate victory. Dr. Thompson, whom I have quoted before, says of this 

battle: 

"Thus the fortunes of war in this battle saw Myer's system of signals succeed, ironically, on the 

side hostile to Myer. Because of general unpreparedness and also some disinterest and ignorance, the North had neither wig-wag signals nor balloon observations." 

The only communication system which succeeded in signal work for the Union Army was 

the infant USMTC. But the Confederate system under Alexander, off to a good start at 

Bull Run, throughout the war operated with both visual and electric telegraphy, and the Confederates thought highly enough of their signal service to establish it on an official basis, on 19 

April 1862, less than a year after that battle. Thus, although the Confederate Signal Corps 

never became a distinct and independent branch of the Army as did the Union Signal Corps, 

it received much earlier recognition from the Confederate Government than did the Signal 

Corps of the Federal Government. Again quoting Dr. Thompson: 

"The Confederate Signal Corps was thus established nearly a year earlier than its Federal counterpart. It was nearly as large, numbering some 1,500, most of the number, however, serving 

on detail. The Confederate Signal Corps used Myer's system of flags and torches. The men 

were trained in wire telegraph, too, and impressed wire facilities as needed. But there was nothing in Richmond or in the field comparable to the extensive and tightly controlled civilian military telegraph organization which Secretary Stanton ruled with an iron hand from Washington." 

We come now to the codes and ciphers used by both sides in the war, and in doing so we must 

take into consideration the fact that on the Union side, there were, as I have indicated, two 

separate organizations for signal communications; one for visual signaling, the other for electric. 

We should therefore not be too astonished to :find that the cryptosystems used by the two 

competing organizations were different. On the other hand, on the Confederate side, as just 

noted, there was only one organization for signal communications, the Signal Corps of the 

Confederate States Army, which used both visual and electric telegraphy, the latter facilities 

being taken over and employed when and where they were available. There were reasons for 

this marked difference between the way in which the Union and the Confederate signal operations were organized and administered but I do not wish to go into them now. One reason, 

strange to say, had to do with the difference between the cryptocommunication arrangements 

in the Union and in the Confederate Armies. 

61 OONPIBBN'l'IAL 
REF ID:A63860 

CONflBtlN'flAL 

We will discuss the cryptosystems used by the Federal Signal Corps first and then those of 

the Confederate Signal Corps. Since both corps used visual signals as their primary means, 

we find them em.ploying Myer's visual-signaling code shown above. At :first both sides sent 

unenciphered messages; but soon after learning that their signals were being intercepted and 

were being read by the enemy, each side decided to do something to protect its messages. 

Initially both decided on the same artifice, viz, changing the visual-signaling equivalents for 

the letters of the alphabet, so that, for instance, "22" was not always "A", etc. This sort of 

changing-about of values soon became impractical, since it prevented memorizing the wig-wag 

equivalents once and for all. The difficulty in the Union Army's Signal Corps was solved by 

the introduction into usage of a cipher disk invented by Myer himself. A full description of 

the disk in its various embodiments will be found in Myer's Manual., but here's a picture of 

three forms of it. You can see how readily the visual wig-wag equivalents for letters, :figures, 

etc., can be changed according to some pre-arranged indicator for juxtaposing concentric disks. 

In my Fig. 55 the top left disks (Fig. 1 of Myer's Plate XXVI) show that the letter A is represented by 112, B, by 22, etc. By moving the two circles to a different juxtaposition a new 

set of equivalents will be established. Of course, if the setting is kept fixed for a whole message the encipherment is strictly monoalphabetic; but Myer recommends changing the setting 

in the middle of the message or, more specifically, at the end of each word, thus producing a 

sort of polyalphabetic cipher which would delay solution a bit. An alternative way, Myer 

states, would be to use what he called a "countersign word," but which we call a key woTYl, 

each letter of which would determine the setting of the disk or for a single word or for two consecutive words, etc. Myer apparently did not realize that retaining or showing externally, that 

is, in the cipher text, the lengths of the words of the plain text very seriously impairs the security of the cipher message. A bit later we shall discuss the secmity afforded by the Myer 

disk in actual practice. 

In the Confederate Signal Corps, the system used for encipherment of visual signals was 

apparently the same as that used for enciphering telegraphic messages, and we shall soon see 

what it was. Although Myer's cipher disk was captured a number of times, it was apparently 

disdained by the Confederates, who preferred to use a wholly different type of device, as will 

be described presently, for both visual and electric telegraphy. 

So much for the cryptosystems used in connection with visual signals by the Signal Corps 

of both the North and the South, systems which we may designate as "tactical ciphers." We 

come now to the systems used for what we may call "strategic ciphers," because the latter 

were usually exchanged between the seat of Government and field commanders, or among the 

latter. In the case of these communications the cryptosystems employed by each side were 

quite different. 

On the Northern side the USMTC used a system based upon what we now call transposition 

but in contemporary accounts they were called "route ciphers" and that name has stuck. 

The designation isn't too bad, because the processes of encipherment and decipherment, though 

dealing not with the individual letters of the message but with entire words, involves following 

the prescribed paths or routes in a diagram in which the message is written. I know no simpler 

or more succinct description of the route cipher than that given by one of the USMTC operators, J. E. O'Brien, in an article in Century Magazine, XXXVIII, September 1889, entitled 

"Telegraphing in Battle": 

"The principle of the cipher consisted in writing a message with an equal number of words in each 

line, then copying the words up and down the columns by various routes, throwing in an extra 

word at the end of each column, and substituting other words for important names and verbs." 

A more detailed description in modern technical terms would be as follows: A system in 

which in encipherment the words of the plaint.ext message are inscribed within a matrix of a 

speci:fied number of rows and columns, inscribing the words within the matrix from left to right, 

in successive lines and rows downward as in ordinary writing, and taking the words out of the 

matrix, that is, transcribing them, according to a prearranged route to form the cipher message. 

62 
REF ID:A63860 

The specific routes to be followed were set forth in numbered booklets, each being labeled 

"W a:r Department Cipher" followed by a number. In referring to them hereinafter I shall use 

the term "cipher books," or sometimes, more simply, the term "ciphers," although the cryptosystem involves both cipher and code processes. It is true that the basic principle of the syst.em, that of transposition, makes the system technically a cipher system as defined in our 

modern terminology; but the use of "arbitraries," as they were called, that is, words arbitrarily 

assigned to represent the names of persons, geographic points, important nouns and verbs, 

etc .• makes the system technically a code system as defined in our modern terminology. 

Figure l 

TwoDisci;, 

1911 ... 

Verucal S ecuon 

Figure 3. 

-3& 

Plan for Service Disc!> 

Figure 2. 

Two Discs. 

t•iguT"e !i 

:~E~~::- :f"'~:.-4'!:. am 

VerUcal Secnon exlubitmg plan fbr four Discs. 

Figure 55. 

63 OONFIBRNHAL 
REF ID:A63860 

Th.ere were in all about a dozen cipher books used by the USMTC throughout the war. For 

the most part they were employed consecutively, but, it seems that sometimes two different 

ones were employed concurrently. They contained not only the specific routes to be used but 

also indicators for the routes and for the sizes of the matrices; and, of course, there were lists 

of code words, with their meanings. These rout.e ciphers were supposed to have been the invention of Anson Stager, whom I have mentioned before in connection with the establishment 

of the USMTC, and who is said to have first devised such ciphers for General McClellan's use 

in West Virginia, in the summer of 1861, before McClellan came to Washington to assume command of the Army of the Potomac. 

Anson Stager and many others thought that he was the original inventor of the syst.em, but 

such a belief was quit.e in error because word-transposition methods similar to Stager's were in 

use hundreds of years before his time. For instance, in 1685, in an unsuccessful att.empt to 

invade Scotland, in a conspiracy to set the Duke of Monmouth on the throne, Archibald Campbell, 9th Earl of Argyll, suffered an unfortunat.e "accident." He was taken prisoner and beheaded by order of James the Second. The communications of the poor Earl were not secure, 

and when they fell into government hands they were soon deciphered. The method Argyll 

used was that of word transposition, and if you are int.erest.ed in reading a cont.emporary 

account of how it was solved, look on pages 56-59 of that little book I mentioned before as 

being one of the very first books in English dealing with the subject of cryptology, that by 

James Falconer, ~ntitled Crypt:omenysis Pat,efacta: Or f:he Art of Secret Information Disclosed 

Without a Key, published in London in 1685. There you will find the progenitor of the rout.e 

ciphers employed by the USMTC, 180 years aft.er Argyll's abortive rebellion. 

The rout.e ciphers employed by the USMTC are fully described in a book entitled The Military Telegraph during f:he Civil War, by Colonel William R. Plum, published in Chicago in 1882. 

I think Plum's description of them is of considerable int.erest and I recommend his book to those 

of you who may wish to learn more about them, but they are pretty much all alike. If I show 

you one example of an actual message and explain its encipherment and decipherment I will 

have covered practically the entire gamut of the rout.e ciphers used by the USMTC, so basically 

very simple and uniform were they. And yet, believe it or not, legend has it that the Southern 

signalmen were unable to solve any of the messages transmitt.ed by the USMTC. This longheld legend I find hard to believe. In all the descriptions I have encount.ered in the lit.erature 

not one of them, save the one quot.ad above from O'Brien, tries to make these ciphers as simple 

as they really were; somehow, it seems to me, a subconscious realization on the part of Northern 

writ.ers, usually ex-USMTC operators, of the syst.em's simplicity prevent.ad a presentation 

which would clearly show how utt.erly devoid it was of the degree of sophistication one would 

be warranted in expecting in the secret communications of a great modem army in the decade 

1860--1870, three hundred years aft.er the birth of modern cryptography in the papal states of 

Italy. 

Let us take the plain text of a message which Plum (p. 58) used in an example of the procedure in encipherment. The cipher book involved is No. 4 and I happen to have a copy of it 

so we can easily check Plum's work. Here's the message to be enciphered: 

For Simon Cameron 

Washington, D. C. 

July 15, 1863 

I would give much to be relieved of the impression that Meade, Couch, Smith and all, since 

the battle of Gettysburg, have striven only to get the enemy over the river without another 

:fight. Please tell me if you know who was the one corps commander who was for :fighting, in 

the council of war on Sunday night. 

(Signed) A. Lincoln 

64 
.. 

REF ID:A63860 

CONFIMN'ftAL 

Plum shows the word-for-word encipherment in a matrix of seven columns and eleven rows. 3 

He fails to tell us why a matrix of those dimensions was selected; presumably the selection was 

made at random, which was certainly permissible. (See Fig. 56.) 

Note the seven "nulls" (non significant, or "blind" words) at the tops and bottoms of certain 

columns, these being added to the cipher text in order to confuse a would-be decipherer. At 

least that was the theory, but how effective this subterfuge was can be surmised, once it became 

known that employing nulls was the usual practice. Note also the two nulls (bless and him) 

at the end of the last line to complete that line of the matrix. Words in italics are "arbitraries" 

or code words. 

The cipher message is then copied down following the route prescribed by the indicator 

"BLONDE," as given on page 7 of Cipher Book No. 4 for a message of 11 lines. The indicator could have also been "LINIMENT." 

1 2 3 4 5 6 7 

(heavy (county) (square) 

(null) (null) (null) 

Incubus Stewart Brown Norris Knox Madison 

Wash., D.C. July 15th 18 60 3 for 

sigh man Cammer on :fl.ea I wood 

Simon Cameron (period) I would 

give much Toby trammeled serenade impression that 

give much to be relieved of the impression that 

Bunyan bear ax cat chil,dren and awl 

Meade , (comma) Couch , (comma) Smith and all 

bat since the knit of get ties 

, (comma) since the battle of Gettys 

large ass have striven only to get 

burg , (comma) have striven only to get 

village skeleton turnip without another optic hound 

the enemy over the river without another fight (period) 

Please tell me if you no who 

Please tell me if you know who 

was the Harry Madrid locust who was 

was the one corps commander who was 

for oppressing bit.ch quail counsel of war 

for fighting , (comma) in the council of war 

on Tyl.er Rustle upright Adrian bless him 

on Sunday night Signature A. Lincoln (null) (null) 

(monkey) (silk) (martyr) (suicide) 

(null) (null) (null) (null) 

Figure 56. 

To explain the diagram at the top of Fig. 57 I will show you the "Directions for Use" which 

appear on the reverse side of the title page of "War Department Cipher No. 4," because I'm 

afraid you wouldn't believe me if I merely told you what they say. In Fig. 58 is a picture of 

the title page and I follow it with Fig. 59, a photograph of what's on its reverse. 

Do you imagine that the chap who was responsible for getting this cipher book approved 

ever thought about what he was doing when he caused those "Directions for Use" to be printed? It doesn't seem possible. All he would have had to ask himself was, "Why put this piece of 

information in the book itself? Cipher books before this have been captured. Suppose this 

•Ruled paper was provided to aid in accuracy. In the diagram the upper of each pair of lines of writing 

is the cipher, the lower one, the plain text. Simon Cameron was Lincoln's Secretary of War until Jan. 1862, 

when he was replaced by Edwin M. Stanton. If this message cited by Plum is authentic, and there is no 

reason to doubt this, then Cameron was still in friendly contact with Lincoln, possibly as a special observer. 

65 CONFl:BEN'l'IAI. 
COffli'fBEN'f'IAL 

..._ 

...... 

... 

mn 

mu., 

.. ~ .... 

,.. ... m • .., 

-... 

.... 

..... 

.... 

REF ID:A63860 

/ _,.., .( _,_ 3 , ...... + __ . ..., ,r 

b ·- T 

'? 

~ '" .. ______ 1::: 

_, .. ....... 

~I' -1,l~n& 

/A[ -- --- --""" /p _....,.. 

1-f - ...... /r //, - -------~.'.: 

'){ .... ,;f _,_., ~!"- ____________ .... _ -fk .. .... 1.ua.,. 

Figure 57. 

one falls into enemy hands; can't he read, too, and at once learn about the int.ended deception? 

Why go to all the trouble of including "phoney" routes anyway? If the book doesn't fall 

into enemy hands what good are the "phoney" routes anyway? Why not just indicate the 

routes in a straight-forward manner, as had been done before? Thus: "Up the 6th column 

(since "6" is the first number at the left of the diagram), down the 3rd, up the 5th, down the 

7th, up the 1st, down the 4th and down the 2nd." This matter is so incredibly fatuous that 

it is hard to understand how sensible men-and they were sensible-could be so illogical in 

their thinking processes. But there the "Directions for Use" stand, for all the world to see 

and to judge. 

WAR DEP~\RT1IENT GIPHER XO. -1. 

Figure 58. 

66 

DIRECTIONS FOR USE 

·ru lmJ till' 11111t1•, rC'1ul tlw h,l!'ur1• .. m tlll t.1hh .• 1t l11p 111 p.1J!1 hum 1Pft 

to rlJ!ht m Liii' 1nrh•1 thnt 1111 \ uu•ur .1lh•r11o1t.i..'h in tlu U}ll'l'f ,11111 lmH•r 

llll\'14 Uw t\\u int1•11mch.1h· l11u~ ur lip:Url"" h.l\tng ll11101llll'<hUll \\llh 

tlw w11l1• 1 1.11 mg mtrmlm•1 cl ... 1111pl~ .11" .1 hhncl, the. upp1•r 11111 of hJr1111.J1 

rl1•1111lmJ[ tlw r11ut1• 1/11ri ''till' 1 nlnmn .m•l tl11 ln\\c•r hni "I' 

Jo:'~A)IPI I 

:-.1•1 p.11-rc.· 14, i 111lu111ntc 

R1111l1-rp tlu ac1 I thmn tin- nth I up tlw lt1t I 1111\\U tlw 7th, up tlw 

21\, drl\\ 11 tin• Ith, up thu &th 

(\lllllllt'l\Cl' .1 C'IJ1h111 \\Ith nm ur th1• • hue mchc..lton-,' t.1L.1•11 fn1m 

P.mw fl'lA:<' ns:: 1out1 u .. ~,1. \\Im h \\orcl mn..it m1lu nk till" 11111111"' 1 ut lnwis 

11\ tlh' llll"Sliilft'~ t•.a(• l\\O \\Or1l .. r11r nlCll'\ th,111 t11r11tg lllll'tl 

Figure 59. 
.. 

REF ID:A63860 

CO:tql"lf1EN'flAL 

Now for the transposition step. The indicator "BLONDE" signifies a matrix of seven 

columns and eleven rows, with the route set forth above, viz, up the 6th column, down the 3rd, 

etc., so that the cipher text with a "phoney" address and signature, 4 becomes as follows: 

TO A. HARPER CALDWELL, Washington, D. C. 

Cipher Operator, Army of the Potomac: 

Blonde bless of who no optic to get and impression I Madison square Brown cam.mer Toby 

ax the have turnip me Harry bitch rustle silk Adrian counsel locust you another only of children 

serenade fl.ea Knox County for wood that awl ties get hound who was war him suicide on for was 

please village large bat Bunyan give sigh incubus heavy Norris on trammeled cat knit striven 

without if Madrid quail upright martyr Stewart man much bear since ass skeleton tell the oppressing Tyler monkey. 

(Signed) D. HOMER BATES 

Note that the text begins with the indicator "BLONDE." In decipherment the steps are 

simply reversed. The indicator tells what size matrix to outline; the words beginning "bless 

of who no optic ... " are inscribed within the matrix: up the 6th column; then, omitting the 

"check word" or "null" (which in this case is the word "square") down the 3rd column, etc. 

The final result should correspond to what is shown in Fig. 56. There then follows the step of 

interpreting orthographic deviations, such as interpreting "sigh," "man," "cammer," and "on" 

as Simon Cameron; the word "wood" for "would," etc. The final step reproduces the original 

plain text. 

Save for one exception, all the route ciphers used by the USMTC conformed to this basic 

pattern. The things that changed from one cipher book to the next were the indicators for 

the dimensions of the matrices and for the routes, and the "arbitraries" or code equivalents 

for the various items comprising the "vocabulary," the number of them increasing from one 

edition to the next, just as might be expected. The sole exception to this basic pattern is to 

be seen in Cipher Book No. 9 and on only one page of the book. I will show you that page. 

(See Fig. 60.) 

What we have here is a deviation from the straightforward route transposition, "up the ... 

column, down the ... column," etc. By introducing one diagonal path in the route (the 6th, 

7th, 8th, 9th, 10th words in a message of five columns, and the 1st, 2nd, 3rd, 4th, 5th, and 6th 

words in a message of six columns) the simple up and down route no longer holds true. The 

words on the diagonal interrupt the normal up and down paths and introduce complexities in 

the method. In fact, the complexities seemed to be a bit too much for the USMTC cipher 

operators because, as far as available records show, these complicated routes were never used. 

I now wish to make a number of general and a few specific comments on Plum's description 

of the cryptosystems used by the USMTC. 

First, we have learned that although Anson Stager has been credited with inventing the type 

of cipher under consideration in this study, he was anticipated in the invention by about 200 

years. Also, he is given the lion's share of the credit for devising those ciphers although he 

did have a number of collaborators. Plum names four of them, presumably because he thought 

them worthy of being singled out for particular attention. Plum and others tell us that copies 

of messages handled by the USMTC were sometimes intercepted by the enemy but not solved. 

He cites no authority for this last statement, merely saying that such intercepts were published 

in the newspapers of the Confederacy with the hope that somebody would come up with their 

solution. And it may be noted that none of the Confederate accounts of war activities cite 

instances of the solution of intercepted USMTC messages, although there are plenty of citations 

of instances of interception and solution of enciphered visual transmissions of the Federal 

Army's Signal Corps. 

•It was the usual practice to use for address and signature the names of the USMTC operators concerned. 

67 GOl>fFIBEN'flAL 
REF ID:A63860 

CONPIBElN'f'IKL 

MtaB11gc 1w Dit:umm of .6. Lines 

COMMENCEMENT WORBS 

I.mcoln . . ... :.7...... . lllcC!elllLn .t;J.. ••• Buell . ..•• . .••...• Yates } 1..- I Stanton } k I Halleck} 7 

Chase 001 u:11'R McDowell co1 uxxs Sibley cm.UHNR 

.Sive11- " 2 .t:"" 2. " RouTF -Up the . -~ column, down the ... w . , up the .. ti. , down the.. .. . ; 

up the .• J. .. , down the .Q., up the •.•• 7 .. 

1ivt columns. If 2~ Z6 16 6 

IJ.I. Zt/ 27 7 s 

/J 23 r- /7 ..; 

I:. 'l .ZS !if J 

10 zz 29 I'! ? 

.... 

II ZI 30 zo I ,. 

" )t Six c"lzzmm. 6 17 27 J,., :2t. lb 

7 5 ZS' 3f ZS" If 

f' 1r 4 34 24 I LI -- "I Jq 2q ... :. z~ /j 

10 2. () 30 33 ., f Z 

II 21 J/ 3 2. 22 I 

Figure 60. 

Plum states that 12 different cipher books were employed by the Telegraph Corps, but I 

think there were actually only eleven. The :first one was not numbered, and this is good 

evidence that a long war was not expected. This :first cipher book had 16 printed pages. 

But for some reason, now impossible to fathom, the sequence of numbered books thereafter 

was as follows: Nos. 6 and 7, which were much like the :first (unnumbered) one; then came 

Nos. 12, 9, 10-in that strange order; then came Nos. 1 and 2; :finally came Nos. 3, 4, and 5. 

(Apparently there was no No. 8, or No. 11-at least they are never mentioned.) It would be 

ridiculous to think that the irregularity in numbering the successive books was for the purpose 

of communication security, but there are other things about the books and the cryptosystem 

that appear equally silly. There may have been good reasons for the erratic numbering of the 

books, but if so, what they were is now unknown. Plum states that No. 4, the last one used 

in the war, was placed into effect on 23 March 1865, and that it and all other ciphers were 

discarded on 20 June 1865. However, as noted, there was a No. 5, which Plum says was given 

a limited distribution. I have a copy of it, but whether it was actually put into use I do not 

know. Like No. 4, it had 40 pages. About 20 copies were sent to certain members of the 

USMTC, scattered among 12 states; and, of course, Washington must have had at least one 

copy. 

We may assume with a fair amount of certainty that the first (the unnumbered) cipher book 

used by the USMTC was merely an elaboration of the one Stager produced for the communi68 
.. 

REF ID:A63860 

cations of the governors of Ohio, Indiana and Illinois, and of which a copy is given by only 

one of the writers who have told us about these ciphers, namely, David H. Bat.es. Bates, in 

his series of articles entitled "Lincoln in the Telegraph Office" (The Cent;ury Magazine, Vol. 

LXXIV, Nos. 1-5, May-Sept, 1907) 5 shows a facsimile thereof (p. 292, June 1907 issue), and I 

have had as good a reproduction made of it as is possible from the rather poor photographic 

facsimile. The foregoing cipher is the prototype upon which all subsequent cipher books were 

based, the first of the War Department series being the one shown by Plum. 

Figure 61. 

When these ciphers came into use it was not the practice to misspell certain words intentionally; but as the members of the USMTC (who, as I've told you, not only served as telegraph 

operators but also as cipher clerks) developed expertness, the practice of using nonstandard 

orthography was frequently employed to make solution of messages more difficult. You have 

already seen examples of this practice, and one can find hundreds of other examples of this 

sort of artifice. Then, further to increase security, more and more code equivalents were 

added to represent such things as ordinal and cardinal numbers, months of the year, days of 

the week, hours of the day, punctuation, etc. AB a last step, additional code equivalents for 

frequently used words and phrases were introduced. One good example of two typical pages 

from one of these books will characterize them all. 

You will notice that the code equivalents are printed but their meanings are written in by 

hand. This was usually the case, and the reason is obvious: for economy in printing costs, 

because the printed code equivalents of plaint.ext items in cipher books belonging to the same 

series are identical; only their meanings change from one book to another, and of course, the 

transposition rout.es, their indicators, and other variables change from one book to another. I 

6 The series was then put out in book form under the same title by the Appleton-Century Company, 

New York, 1907, reprinted in 1939. 

69 OONPIBBN'l'IAL 
BJrua.--- - ...... .,.. .,_ • C"1i!ul4. --~'1Wk. _ 

......, b"1fJuni - • _____ ftJ:JtJJ.taM.._ ...... ,__ -- ___ f"1i.cii ..... -- ~ - __ ,Ar&l/l<I - -- __ f'"f)"1:1! 

• Dnall 

-

REF ID:A63860 

12 

.st 11w. 1i.111... - __ 9'1!'flik.£H!f« 

..... ~ '3uu.~ 

... _ --- - --hu~- ...... _ "1"11111't~l11« 

.... l'.m.iCMM._ ,..... htmw.n,1r1n ,.,.. Mat.01'1'tM. ...... _______ Ji'IM~ --

m... N _ LCdf.M4w..u 

...... , UN.!c..&.1o.1t1 

"-• - ---~ 

.... 

Figure 62. 

...... .1 .... .,n1 

·•pl•• 

........ 

..... 

....... 

am fortunate in having six of these cipher books in my private collection, so that comparisons 

among them are readily made. The :first feature to be noted is that the code equivalents are 

all good English dictionary words (or proper nouns), of not less than three nor more than seven 

(rarely eight) letters. A careful scrutiny shows that in the early editions the code equivalents 

are such as are not very likely to appear as words in the plaintext messages; but in the later 

editions, beginning with No. 12, more tko.n 50% of the words used as code equivalents are such as 

might well appear in the plain t,ext of messages. For example, words such as AID, ALL, ARMY, 

ARTILLERY, JUNCTION, CONFEDERATE, etc., baptismal names of persons, and names 

of cities, rivers, bays, etc., appear as code equivalents. Among names used as code equivalents 

are SHERMAN, LINCOLN, THOMAS, STANTON, and those of many other prominent 

officers and officials of the Union Army and the Federal Government, as well as of the Confederate Army and Government; and, even more intriguing, such names were employed as 

indicators for the number of columns and the routes used-the so-called "Commencement 

Words." It would seem that names and words such as those I've mentioned might occasionally 

have brought about instances where difficulty in deciphering messages arose from this source 

of confusion, but the literature doesn't mention them. I think you already realize why such 

commonly used proper names and words were not excluded. There was, indeed, method in 

this madness. 

But what is indeed astonishing to note is that in the later editions of these cipher books, in 

a great majority of cases, the words used as "arbitraries" differ from one another by at least 

two letters (for example, LADY, and LAMB, LARK and LAWN, ALBA and ASIA, LOCK 

and WICK, MILK and MINT), or by more than two (for example MYRTLE and MYSTIC, 

CARBON and CANCER, ANDES and ATLAS). One has to search for cases in which two 

words differ by only one letter, but they can be found if you search long enough for them, as, 

for example, QUINCY and QUINCE, PINE and PIKE, NOSE and ROSE. Often there are 

words with the same initial trigraph or tetragraph, but then the rest of the letters are such 

that errors in transmission or reception would easily manifest themselves, as, for example, in 

the cases of MONSTER and MONARCH, MAGNET and MAGNOLIA. All in all, it is 

important to note that the compiler or compilers of these cipher books had adopted a principle 

known today as the "two-letter differential," a feature found only in codebooks of a much later 

date. In brief, the principle involves the use, in a given codebook, of code groups differing 

OONflB:eN'f'fAL 70 
REF ID:A63860 

from one another by at least two letters. This principle is employed by knowledgeable code 

compilers to this very day, not only because it enables the recipient of a message to detect 

errors in transmission or reception, but also to correct them. This is made possible if the 

permutation tables used in constructing the code words are printed in the codebooks, so that 

most errors can be corrected without calling for a repetition of the transmission. It is clear, 

therefore, that the compilers of these cipher books took into consideration the fact that errors 

are to be expected in Morse telegraphy, and by incorporating, buL only to a limited extent, 

the principle of the two-letter differential, they tried to guard against the possibility that 

errors might go undetected. Had artificial 5-letter groups been used as code equivalents, 

instead of dictionary words, possibly the cipher books would also have contained the permutation tables. But it must be noted that permutation tables made their first appearance only 

tbout a quarter of a century after the Civil War had ended, and then only in the most advanced 

aypes of commercial codes. 

There is, however, another feature about the words the compilers of these books chose as 

code equivalents. It is a feature that manifests real perspicacity on their part, and you probably already have divined it. A few moments ago I said that I would explain why, in the 

later and improved editions of these books, words which might well be words in plaintext 

messages were not excluded from the lists of code equivalents: it involves the fact that the 

basic nature of the cryptosystem in which these code equivalents were to be used was clearly 

recognized by those who compiled the books. Since the cryptosystem was based upon word 

transposition, what could be more confusing to a would-be cryptanalyst, working with messages in such a system, than to find himself unable to decide whether a word in the cipher text 

of a message he is trying to solve is actually in the original plaintext message and has its normal meaning, or is a code word with a secret significance-or even a null, a nonsignificant word, 

a "blind" or a "check word," as those elements were called in those days? That, no doubt, 

is why there are, in these books, so many code equivalents which might well be "good" words 

in the plaintext messages. And in this connection I have already noted an additional interesting 

feature: at the top of each page devoted to indicators for signaling the number of columns or 

rows in the specific matrix for a message are printed the so-called "commencement words," or 

what we now call "indicators." Now there are nine such words, in sets of three, any one of 

which couUl actually be a real word or name in the plaintext message. Such words when used 

as indicators could be very confusing to enemy cryptanalysts, especially after the transposition 

operation. Here, for example, are the "commencement words" on page 5 of cipher book No. 

9: Army, Anson, Action, Astor, Advance, Artillery, Anderson, Ambush, Agree; on page 7 of 

No. 10: Cairo, Curtin, Cavalry, Congress, Childs, Calhoun, Church, Cobb, etc. Moreover, 

in Nos. 1, 3, 4, 5, and 10 the "line indicators," that is, the words indicating the number of horizontal rows in the matrix, are also words such as could easily be words in the plaintext messages. 

For example, in No. 1, page 3, the line indicators are as follows: 

Address 

Adjust 

Answer 

Appear 

Appeal 

1 

2 

3 

4 

5 

Faith 

Favor 

Confine 

Bed 

Beef 

Assume 6 

Awake 7 

Encamp 8 

Enroll 9 

Enough 10 

Bend 

Avail 

Active 

Absent 

Accept 

Note two things in the foregoing list: first, there are variants-there are two indicators for 

each case; and second, the indicators are not in strict alphabetic sequence. This departure 

from strict alphabeticity is even more obvious in the pages devoted to vocabulary, a fact of 

much importance cryptanalytically. Note this feature, for example, in Fig. 62, which shows 

pages 14 and 15 of cipher book No. 12. 

In this respect, therefore, these books partake somewhat of the nature of two-part or "randomized" codes, or, in British terminology, "hatted" codes. In the second lecture of this 

series the physical difference between one-part and two-part codes was briefly explained, but 

71 C~EPA?fAL 
REF ID:A63860 

CONflBBN'f'fAL 

an indication of the technical cryptanalytic difference between these two types of codes may 

be useful at this point. Two-part codes are much more difficult to solve than one-part codes, 

in which both the plaintext elements and their code equivalents progress in parallel sequences. 

In the latter type, determination of the meaning of one code group quickly and rather easily 

leads to the determination of the meanings of other code groups above or below the one that 

has been solved. For example, in the following short but illustrative example, if the meaning 

of code group 1729 has been determined to be "then," the meaning of the code group 1728 

could well be "the" and that of 

1728-the 

1729-then 

1730-there 

7621-the 

0972-then 

1548-there 

the code group 1730, "there." But in a two-part code, determining the meaning of the code 

group 0972 to be "then" gives no clue whatever as to the meaning of the groups 7621 or 1548. 

For ease in decoding messages in such a code there must be a section in which the code groups 

are listed in numerical sequence and are accompanied by their meanings, which, of course, 

will be in a random sequence. The compilers of the USMTC cipher books must have had a 

very clear idea of what I have just explained, but they made a compromise of a practical nature 

between a strictly one-part and a strictly two-part code, because they realized that a code of 

the latter sort is twice as bulky as one of the former sort, besides being much more laborious 

to compile and check the contents for accuracy. The arrangement they chose wasn't too bad, 

so far as cryptosecurity was concerned. As a matter of fact, and speaking from personal 

experience in decoding a rather long message addressed to General Grant, I had a difficult time 

in locating many of the code words in the book, because of the departure from strict alphabeticity. I came across that message in a workbook in my collection, the workbook of one of 

the important members of the USMTC-none other than our friend Plum, from whose book, 

The Milita,ry Telegraph during the Civil War, comes much of the data I've presented in this 

lecture. On the :flyleaf of Plum's workbook there appears, presumably in his own handwriting, 

the legend "W.R. Plum Chf Opr with Gen. G. H. Thomas." Here's one of the messages he 

enciphered in cipher book No. 1, the book in which, he says, more important telegrams were 

sent than in any other: 

~'I I ., , A,."Lt -

.=> k ~-

- - -- ,. 

hi. - "~ ... , .. . • .. ... - ,, ~· . ~ . . I_,_ .,._ ·- " ,_ ..... r_ L , 

... , .... £(_ 6 "ff".. ( ,.,..,.. ........ ~ ~.( '. ..,,_ ,,_ 

-- a fl-9 '""- IA•.T-. "' -•- • 

I r 

r.!-, ..... -- ~ 

1, , a l , 3 ~a 

l'·'-"J7-

I I 

I I 

Figure 63. 

Note how many "arbitraries" appear in the plaintext message, that is before transposition. 

After transposition, the melange of plain text, code words, indicators and nulls makes the cryp72 
,. 

REF ID:A63860 

CoNFEDEKATE STATES CIPHER KEY. 

-~ussnmooWIBflWWMIBHUW987654821 

1 ab c def g hi j k I mn op qr a u v w x y z 

2 b c def g hi j k Im no p qr at u vw x y z a 

3 c d e f g h i j k l m n o p q r a t u v w x y z a b 

4 def g hi j k I mn op qr st u v w x y z ab c 

rs erg hi j kl mn 0 p qr & tu vw x: y z ab c d 

6 r g h i j k 1 m n o p q r s t u v w x y z a b c d e 

7 g h i j k I m n o p q r a t u v w x y z a b c d e r 

8hijklmnopqrstuvwxyzabcdefg 

9 l j k 1 m D 0 p qr St U VW X y Z ab Cd 8 f g h 

10 j k 1 mn op qr st u vw x y z ab c de r g h 

11klmnopqrstuvwxyzabcdefgh j 

12 1 mn op qr st u vw x y z ab c de r g hi j k 

18mnopqrstuvwx:yzabcdefghijkl 

14 no p qr at u vw x y z ab c de r g hi j k 1 m 

15 op qr at u vw x: y z ab c def g hi j k 1 m n 

16 p qr at u vw x y z ab c def g hi j k 1 m no 

17 q r a t u v w x y z a b c d e f g h i j k 1 m n o p 

18ratuvwxyzabcdefgh jklmnopq 

19 a t u v w x y z a b c d e r g h i j k 1 m n o p q r 

20tuvwxyzabcdefghijklmnopqrs 

21 u vw x y z ab c de r g hi j k 1 mn op qr st 

S2vwxyzabcde fghi j k lmnopqr st u 

2Sw x y z ab c de r g hi j k 1 mn op qr st u v 

M x y z ab c de r g hi j k 1 mn op qr at u vw 

Iii y z ab c de r g hi j k 1 mn op qr at u vw x 

Hz ab c de r g hi j k 1 mn op qr st u vw x y 

Figure 64. 

togram mystifying. 6 And yet, was the system as inscrutable as its users apparently thought? 

It is to be remembered, of course, that messages were then transmitted by wire telegraphy, 

not by radio, so that enemy messages could be obtained only by "tapping" telegraph lines or 

capturing couriers or headquart.ers with their files intact. Opportunities for these methods of 

acquiring enemy traffic were not frequent, but they did occur from time to time, and in one 

case a Confederate signalman hid in a swamp for several weeks and tapped a Federal telegraph 

line, obtaining a good many messages. What success, if any, did Confederate cryptanalysts 

have in their attempts to solve such USMTC cryptograms as they did intercept? We shaII 

try to answer this question in due time. 

As indicated earlier, there were no competing signal organizations in the Confederacy as 

there were on the Union side. Th.ere was nothing at the center of government in Richmond or 

in the combat zone comparable to the extensive and tightly controlled civilian military telegraph organization which Secretary Stanton ruled with such an iron hand from Washington. 

Almost as a concomitant, it would seem, there was in the Confederacy, save for two exceptional 

cases, one and only one officially established cryptosystem to serve the need for protecting 

tactical as well as strategic communications, and that was the so-called Vigenere Cipher, which 

apparently was the cipher authorized in an official manual prepared by Captain J. H. Alexander 

as the partial equivalent of Myer's Manual of Signals. You won't find the name Vigenere in 

11 In searching for a good example my eye caught the words "Lincoln shot" at the left of the matrix and I 

immediately thought that the message had to do with Booth's assassination of the President. But after hurriedly translating the message and finding nothing in it having anything to do with the shooting it occurred 

to me to look up the indicators for a matrix of six rows and eight columns. They turned out to be LINCOLN 

(message of 8 columns), SHOT (6 rows). The word SMALL beneath the "Lincoln shot" is a variant for 

SHOT, also meaning "6 rows." 

73 
REF ID:A63860 

GON.FHlB'N'l'li\:l• 

any of the writings of contemporary signal officers of either the North or the South. The 

signalmen of those days called it the "Court Cipher," this term referring to the system in 

common use for diplomatic or "court" secret communications about this period in history. It 

is that cipher which employs the so-called Vigenere Square with a repeating key. 7 Here in 

Fig. 64 is the square which Plum calls the "Confederate States Cipher Key" and which is 

followed by his description of its manner of employment. 

There are certain comments to be made on the two sample messages given by Plum. In the 

first place, in one of the messages certain words are left unenciphered; in the second place, in 

both sample messages, the ciphers retain and clearly show the lengths of the words which have 

been enciphered. Both of these faulty practices greatly weaken the security of ciphers because 

they leave good clues to their contents and can easily result in facilitating solution of the messages. We know today that cipher messages must leave nothing in the clear. Even the 

address and the signature, the date, time and place of origin, etc., should if possible be hidden; 

and the cipher text should be in completely regular groupings, first, so as not to disclose the 

lengths of the plaintext words, and second, to promote accuracy in transmission and reception. 

So far as my studies have gone, I have not found a single example of a Confederate Vigenere 

cipher which shows neither of these two fatal weaknesses. The second of the two examples is 

the only case I have found in which there are no unenciphered words in the text of the message. 

And the only example I have been able to :find in which word lengths are not shown (save for 

one word) is in the case of the following message: 

Vicksburg, Dec. 26, 1862. 

GEN. J.E. JOHNSTON, JACKSON: 

I prefer oaavvr, it has reference to xhvkjqchffabpzelreqpzwnyk to prevent anuzeyxswstpjw at 

that point, raeelpsghvelvtzfautlilaslt lhifnaigtsmmlfgccajd. 

(Signed) J. C. PEMBERTON 

Lt. Gen. Comdg. 

Even in this case there are unenciphered words which afforded a clue which enabled our man 

Plum to :find the key and solve the message. It took some time, however, and the story is 

worth telling. 

According to Plum, the foregoing cipher message was the very first one captured by USMTC 

operators, and it was obtained during the siege of Vicksburg, which surrendered on 4 July 1863. 

But note the date of the message: 26 December 1862. What was done with the captured 

message during the months from the end of December 1862 to July 1863? Apparently nothing. 

Here is what Plum reports: 

"What efforts General Grant caused to be made to unravel this message, we know not. It was 

not until October, 1864, that it and others came into the hands of the telegraph cipherers, at 

New Orleans, for translation .... 

The New Orleans operators who worked out this key (Manchester Bluff) were aided by the 

Pemberton cipher and the original telegram, which was found among that general's papers, after the surrender of Vicksburg; also by the following cipher dispatch, and one other." 

Plum gives the messages involved, their solution, and the keys, the latter being the three 

cited above. It would seem that if the captured Pemberton message had been brought to 

General Grant's attention and he did nothing about it, he was not much interested in intelligence. Secondly, the solution of the Pemberton message and the others apparently took 

some time, even though there was one message with its plain text (the Pemberton message) 

and two messages not only with interspersed plaint.ext words but also with spaces showing word 

lengths. But Plum does not indicate how long it took for solution. Note that he merely 

says that the messages came into the hands of the telegraph cipherers in October 1864; he does 

not tell when solution was reached. 

1 A key word is employed to change the alphabets cyclically, thus making the cipher what is called today a 

periodic polyalphabetic cipher controlled by the individual letters of a key, which may consist of a word, a 

phrase, or even of a sentence, repeated as many times as necessary. 

74 
REF ID:A63860 

CONPIBBN't'lkL 

In the various accounts of these Confederate ciphers there is one and only one writer who 

makes a detailed comment on the two fatal practices to which I refer. A certain Dr. Charles 

E. Taylor, a Confederate veteran (in an article entitled "The Signal and Secret Service of the 

Confederate States," published in the Confederate Veteran, Vol. XL, Aug-Sept 1932), after 

giving an example of encipherment according to the "court cipher," says: 

"It hardly needs to be said that the division between the words of the original message as given 

above was not retained in the cipher. Either the letters were run together continuously or 

breaks, as if for words, were made at random. Until the folly of the method was revealed by 

experience, only a few special words in a message were put into cipher, while the rest was sent 

in plain language. Thus ... I think it may be said that it was impossible for well prepared cipher to be correctly read by any one who did not know the key-word. Sometimes, in fact, we 

~ould not decipher our own messages when they came over telegraph wires. As the operators 

had no meaning to guide them, letters easily became changed and portions, at least, of messages 

rendered unmeaningly (sic) thereby." 

Frankly, I don't believe Dr. Taylor's comments are to be taken as characterizing the practices that were usually followed. No other ex-signalman who has written about the ciphers 

used by the Confederate Signal Corps makes such observations, and I think we must simply 

discount what Dr. Taylor says in this regard. 

It would certainly be an unwarranted exaggeration to say that the two weaknesses in the 

Confederate cryptosystem cost the Confederacy the victory for which it fought so mightily, 

but I do feel warranted at this moment in saying that further research may well show that 

certain battles and campaigns were lost because of insecure cryptocommunications. 

A few moments ago I said that, save for an exception or two, there was in the Confederacy 

one and only one cryptosystem to serve the need for secure tactical as well as strategic communications. One of these exceptions concerned the cipher used by General Beauregard after 

the battle of Shiloh (8 April 1862). This cipher was purely monoalphabetic in nature and was 

discarded as soon as the official cipher system was prescribed in Alexander's manual. It is 

interesting to note that this was done after the deciphered message crune to the attention of 

Confederate authorities in Richmond via a northern newspaper. It is also interesting to note 

that the Federal War Department had begun using the route cipher as the official system for 

USMTC messages very promptly after the outbreak of war, whereas not until 1862 did the 

Confederate States War Department prepare an official cryptosystem, and then it adopted the 

"court cipher." 

The other exception involved a system used at least once before the official system was 

adopted, and it was so different from the latter that it should be mentioned. On 26 March 

1862, the Confederate States President, Jefferson Davis, sent General Johnston by special 

messenger a dictionary, with the following accompanying instruction: 8 

"I send you a dictionary of which I have the duplicate, so that you may communicate with me 

by cipher, telegraphic or written, as follows: First give the page by its number; second, the 

column by the letter L, M or R, as it may be, in the left-hand, middle, or right.hand columns; 

third, the number of the word in the column, counting from the top. Thus, the word junction 

would be designated by 146, L, 20." 

The foregoing, as' you no doubt have already realized, is one of the types of cryptosystems 

used by both sides during the American Revolutionary Period almost a century before, except 

that in this case the dictionary had three columns to the page instead of two. I haven't tried 

to :find the dictionary but it shouldn't take long to locate it, since the code equivalent of the 

word "junction" was given: 146, L, 20. Moreover, there is extant at least one fairly long 

message, with its decode. How many other messages in this system there may be in National 

Archives I don't know. 

Coming back now to the "court cipher," you will probably find it just as hard to believe, as 

I :find it, that according to all accounts three and only three keys were used by the Confederates 

s Battles and Leaders of 'the Ci1Jil War. The Century Co., New York, 1884, Vol. I, p. 581. 

75 CONFIDENTIAL 
REF ID:A63860 

during the three and a half years of warfare from 1862 to mid-1865. It is true that Southern 

signalmen make mention of frequent changes in key but only the following three are specifically 

cited: 

1) COMPLETE VICTORY 

2) MANCHESTER BLUFF 

3) COME RETRIBUTION. 

It seems that all were used concurrently. There may have been a fourth key, IN GOD 

WE TRUST, but I have seen it only once, and that is in a book explaining the "court cipher." 

Note that each of the three keys listed above consists of exactly 15 letters, but why this length 

was chosen is not clear. Had the rule been to make the cipher messages contain only 5-letter 

groups, the explanation would be easy: 15 is a multiple of 5 and this would be of practical 

value in checking the cryptographic work. But, as has been clearly stated, disguising word 

lengths was apparently not the practice even if it was prescribed, so that there was no advantage in choosing keys which contain a multiple of 5 letters. And, by the way, doesn't the key 

COME RETRIBUTION sound rather ominous to you even these days? 

Sooner or later a Confederate signal officer was bound to come up with a device to simplify 

enciphering operations, and a gadget devised by a Captain William N. Barker seemed to meet 

the need. In Myer's Manual there is a picture of one form of the device, shown here in Fig. 

65. I don't think it necessary to explain how it worked, for it is almost self-evident. Several 

of these devices were captured during the war, one of them being among the items in the NSA 

Museum (Fig. 66). This device was captured at Mobile in 1865. All it did was to mechanize, 

in a rather inefficient manner, the use of the Vigenere Cipher. 

Cipher Beel. 

Figure 65. 

How many of these devices were in existence or use is unknown, for their construction was 

an individual matter-apparently it was not an item of regular issue to members of the corps. 

In practically every account of the codes and ciphers of the Civil War you will find references 

to ciphers used by Confederate secret service agents engaged in espionage in the North as well 

as in Canada. In particular, much attention is given to a set of letters in cipher, which were 

intercepted by the New York City Postmaster and which were involved in a plot to print 

Confederate currency and bonds. Much ado was made about the solution of these ciphers by 

cipher operators of the USMTC in Washington and the consequent breaking up of the plot. 

But I won't go into these ciphers for two reasons. First, the alphabets were all of the simple 

monoalphabetic type, a total of six altogether being used. Since they were composed of a different series of symbols for each alphabet, it was possible to compose a cipher word by jumping 

from one series to another without any external indication of the shift. However, good eyesight 

and a bit of patience were all that was required for solution in this case because of the inept 

manner in which the system was used: whole words, sometimes several successive words, were 

CONflMN'ff AL 76 
REF ID:A63860 

enciphered by the same alphabet. But the second reason for my not going into the story is 

that my friend and colleague of my NSA days, Edwin C. Fishel, has done some research among 

the records in our National Archives dealing with this case, and he has found something which 

is of great interest and which I feel bound to leave for him to tell at some future time, as that 

is his story, not mine. 

Figure 66. 

So very fragmentary was the amount of cryptologic information known to the general 

public in these days that when there was found on John Wilkes Booth's body a cipher square 

which was almost identical with the cipher square which had been mounted on the cipher reel 

found in Confederate Secretary of State Judah P. Benjamin's office in Richmond, the Federal 

authorities in Washington attempted to prove that this necessarily meant that the Confederate 

leaders were implicated in the plot to assassinate Lincoln and had been giving Booth instructions in cipher. Fig. 67 is a picture of the cipher square found on Booth, and also in a trunk 

in his hotel room in Washington. 

The following is quoted from Philip Van Doren Stern's book entitled Secret Missions of the 

Civil War (Rand McNally and Co., New York, 1951, p. 320): 

"Everyone in the War Department who was familiar with cryptography knew that the Vigenere 

was the customary Confederate cipher and that for a Confederate agent (which Booth is known 

to have been) to possess a copy of a variation of it meant no more than if a tele,graph operator 

was captured with a copy of the Morse Code. Hundreds--and perhaps thousands--of people were 

using the Vigenere. But the Government was desperately seeking evidence against the Confederate leaders so they took advantage of the atmosphere of mystery which has always surrounded cryptography and used it to confuse the public and the press. This shabby trick gained 

nothing, for the leaders of the Confederacy eventually had to be let go for lack of evidence." 

To the foregoing I will comment that I doubt very much whether "everyone in the War 

Department who was familiar with cryptography knew that the Vigenere was the customary 

Confederate cipher." Probably not one of them had even heard the name Vigenere or had 

even seen a copy of the table, except those captured in operations. I doubt whether anyone 

on either side even knew that the cipher used by the Confederacy had a name; or least of 

all, that a German Army reservist named Kasiski, in a book published in 1863, showed how the 

Vigenere cipher could be solved by a straightforward mathematical method. 

I have devoted a good deal more attention to the methods and means for cryptocommunications in the Civil War than they deserve, because professional cryptologists of 1961 can 

hardly be impressed either by their efficacy from the point of view of ease and rapidity in the 

77 OONFIBH!ft'IM:a 
REF ID:A63860 

cryptographic processing, or by the degree of the technical security they imparted to the messages they were intended to protect. Not much can be said for the security of the visual 

signaling systems used in the combat zone by the Federal Signal Corps for tactical purposes, 

because they were practically all based upon simple monoalphabetic ciphers, or variations 

thereof, as, for instance, when whole words were enciphered by the same alphabet. There is 

plenty of evidence that Confederate signalmen were more or less regularly reading and solving 

those signals. What can be said about the security of the route ciphers used by the USMTC 

for strategic or high command communications in the zone of the interior? It has already 

been indicated that, according to accounts by ex-USMTC men, such ciphers were beyond the 

cryptanalytic capabilities of Confederate cryptanalysts, but can we really believe that this 

, "'- ,, Jc d'. . '/ .' , I , 

---------. . -- -··--------

-- - --- --======-=-----------

·~ \ ne1il.: i::CTI Ir .f K i. M x o I ·ii l"i~f"1 :-v-\\~~,·=--z-' .\Ul'OJ·:l·'Ulll.rn::LllXOl'(}l~::.:·1T\ \\ XYZ.\ I

BCDEFflill.IKUIXOPclH:--'l l \"\\"X\ 'I .. \ B 

'.CDI-TC:IIl.JKLllXOl'IJH:--TI"\ \\"XYZ.\ll<"., 

'!llEl·'fH!l.IKUIXllJ'cJH:--lT\"\\"XYZ \l;c II 

. I•:l·'Hlll.11\: L::\lXOl'IJ Jt ... TI \"\\" X YZ.\ Ill· 111·: 

F<ill r.JKI,ll X( 11'1/l::--'IT\" W X YZ.\ HI 'IJJ:I-' 

fllll,JKDIXOl'(Jll:-:Tl \"\\")\ YZ.\ Ill 'llEl"(i 

. Hf.JI\: DIXOl'lll::--TI \"\\ X YZ.\IU'llFFl.i Ii 

r .11\:DI XOl'•lH:--TI · r w x YZ.\ l'c ·rn·:rc. 11 ; 1

.11\: I.::\lXOl'Q::..:T!- \" \\" X YZ.\ 1!1 'l>t:Fc i JI I.I 

K LllXOl'IJH<l 1 \ \\" X \ Z.\ ll• 'I ll·:l'C Hi I.I K 

I LllXOl'llH:-O:Tl"\"\\"XYZ.\Bc JlEl'lilll.IK L 

'MXOI 'JH:-'Tl"\"\\ ~ YZ.\llf'Ill:l"lilll.Jl\:L'1 '~Ol'l~H~'l l"\"\\ \ YZ.\IWlli:l·'lilll-1 KUI X 

Ol'l!H.:0:1T\"\\" x y /..\ 1:1'llEF1I111.1 K DI x () l'QH~T( \ \\' ~ \ Z.\ IU'l>I:rn 111.1 '' l.ll ~ 111' 

<lH:-O:Tl ·rwx YZ.\ (IC 'Jll:l"GI I [.IK l.ll ~I ll'IJ 

H:O:Tl" \"\\"XYZ.\ IW!I El'I illl.I KI. \I XI I I'll It 

:-: 'IT\"\\" XYZ.\ HI 'JIEF1ill I.I K UIXOl'lit: : Tl"\'\\" XYZABCJIEI·'( m1.1 K u1xo1·c,1.:--·r 

~ ('\'\\'X YZ.\ Bl 'llEFrnll.11\: L~I xo1·c11::--TI. 

, \"\\'X YZ.\ m ·111-:r<; 111.1 K LM xo1·11r:..:n · ,. 

I

WXYZ.\Bl'lll:F1illl.JKUl'.\11( 1IJH:--'l I \ \\" 

XYl':.\Bl.'lll·:l'nlll.Jl\:l.\IXctl'IJl::--'11 \ \\ X 

ll YZ.\Bl'lll·:l·'Olll.Jl..:L'1Xol'c~B:--TI \"\\ XY 

1,.\ Bl 'llEFG II I.I K DI XOl'llH:..: 11 · \" \\'X YZ 

Figure 67. 

78 
REF ID:A63860 

was true? Considering the simplicity of these route ciphers and the undoubted intellectual 

capacities of Confederate officers and soldiers, why should messages in these systems have 

resisted cryptanalytic attack? In many cases the general subject matter of a message and 

perhaps a number of specific items of information could be detected by quick inspection of 

the message. Certainly, if it were not for the so-called "arbitraries," the general sense of the 

message could be found by a few minutes work, since the basic system must have been known 

through the capture of cipher books, a fRct mentioned several times in the literature. Capture of but one book (they were all generally alike) would have told Confederate signalmen 

exactly how the system worked, and this would naturally give away the basic secret of the 

superseding book. So we must see that whatever degree of protection these route ciphers afforded, message security depended almost entirely upon the number of "arbitraries" actually 

used in practice. A review of such messages as are available shows wide divergencies in the 

use of "arbitraries." In any event, the number actually present in these books must have 

fallen far short of the number needed to give the real protection that a well-constructed code 

can give. Thus it seems to me that the application of native intelligence, with some patience, 

should have been sufficient to solve USMTC messages-or so it would be quite logical to assume. That such an assumption is well warranted is readily demonstrable. 

It was, curiously enough, at about this point in preparing this lecture that Mr. Edwin C. 

Fishel, whom I have mentioned before, gave me just the right material for such a demonstration. In June of 1960, Mr. Fishel had given Mr. Phillip Bridges, who is also a member of 

NSA and who knew nothing about the route ciphers of the USMTC, the following authentic 

message sent on 1 July 1863 by General George G. Meade, at Harrisburg, Pennsylvania, to 

General Couch at Washington. (See Fig. 68.) 

It took Mr. Bridges only a few hours, five or six, to solve the cryptogram, and he handed 

the following plain text to Mr. Fishel: 

Figure 68. 

Thomas been it-(Nulls) 

For Parson. I shall try and get to you by tomorrow morning a reliable gentleman and some 

scouts who are acquainted with a country you wish to know of. Rebels this way have all concentrated in direction of Gettysburg and Chambersburg. I occupy Carlisle. Signed Optic. 

Great battle very soon. tree much deal-(Nulls) 

79 
REF ID:A63860 

C6N'PlrJEN'l'IAL 

The foregoing solution is correct, save for one pardonable error: "Thomas" is not a "null" 

but an indicator for the dimensions of the matrix and the route. "Parson" and "Optic" are 

code names, and I imagine that Mr. Bridges recognized them as such but, of course, he had no 

way of interpreting them, except perhaps by making a careful study of the events and commanders involved in the impending action, a study he wasn't called upon to undertake. 

The foregoing message was enciphered by Cipher Book No. 12, in which the indicator 

THOMAS specifies a "Message of 10 lines and 5 columns." The route was quite simple and 

straightforward: "Down the 1st (column), up the 3rd; down the 2nd; up the 5th down the 

4th." 

It is obvious that in this example the absence of many "arbitraries" made solution a relatively easy matter. What Mr. Bridges would have been able to do with the cryptogram. had 

there been many of them is problematical. Judging by his worksheets, it seemed to me that 

Mr. Bridges did not realize when he was solving the message that a transposition matrix was 

involved; and on questioning him on this point his answer was in the negative. He realized 

this only later. 

A minor drama in the fortunes of Major General D. C. Buell, one of the high commanders 

of the Federal Army, is quietly and tersely outlined in two cipher telegrams. The :first one, 

sent on 29 September 1862, from Louisville, Kentucky, was in one of the USMTC cipher 

books and was externally addressed to Colonel Anson Stager, head of the USMTC, but the 

internal addressee wal!! Major General H. W. Halleck, "General-in-Chief" [our present day 

"Chief of Staff"}. The message was externally signed by William H. Drake, Buell's cipher 

operator, but the name of the actual sender, Buell, was indicated internally. Here's the telegram.: 

COLONEL ANSON STAGER, Washington: 

Austria await I in over to requiring orders olden rapture blissful for your instant command 

turned and instructions and rough looking further shall further the Camden me of ocean September poker twenty I the to I command obedience repair orders quickly pretty Indianapolis 

your him accordingly my fourth received 1862 wounded nine have twenty turn have to to to 

alvord hasty. 

WILLIAM H. DRAKE 

Rather than give you the plain text of this message, perhaps you would like to work it out 

for yourselves, for with the information you've already received the solution should not be 

difficult. The message contains one error, which was made in its original preparation: one 

word was omitted. 

The second telegram., only one day later, was also from Major General Buell, to Major 

General Halleck, but it was in another cipher book-apparently the two books involved were 

used concurrently. Here it is: 

GEORGE C. MAYNARD, Washington: 

Regulars ordered of my to public out suspending received 1862 spoiled thirty I dispatch command of continue of best otherwise worst Arabia my command discharge duty of my last for 

Lincoln September period your from sense shall duties the until Seward ability to the I a removal 

evening Adam herald tribune.1 

PHILIP BRUNER 

As before, I will give you the opportunity to solve this message for yourselves. (At the 

end of the next lecture I shall present the plain text of both messages.) 

Figure 69 is a photograph of an important message which you may wish to solve yourself. 

It was sent by President Jefferson Davis to General Johnston, on a very significant date, 11 

1 A curious coincidence--or was it a fortuitous foreshadowing of an event far in the future?--can be seen in the 

sequence of the last two words of the cipher text. The message is dated September 30, 1862; the New York 

Herald and the New York Tribune combined to make the New York Herald-Tribune on March 19, 1924--62 

years later! 

CONPIMN'flAL 80 
--II!':"·-

• 

,_. - --

,,,...--..-. - ,' -

REF ID:A63860 

- -....-;~· ' .... u; - ~. 

.. 

: 

.... 

(" -.\ 

~. 

.. . ,, /' _,.t' "' • ~.:....- •• ' 

..... 

. ~ - " -

~ 

/' 

' ·-

. . 

,

-. 

.. 

!" 

l I 

' 

c~(\l·r"".., ·-·~_,, V ( . , ' -- \. ~ 

.... 

f. t .... .1 

'-' • ~~ A • / 

Figure 69. 

81 
REF ID:A63860 

April 1865. * For ease in working on it I give also a transcription below, since the photograph 

is very old and in a poor state. I believe that this message does not appear in any of the accounts I've read. 

Greensboro N.C. 

April 11 1865 

Benaja 11 Hd Q near R. G. 

Genl J. E. Johnston 

A scout (reports?) that Genl Lee 

u i D v v s w v z F x - m q s - E G A z o x -

H W - P J M - T z A T - near to appomattox Court 

house yesterday No official intelligence of the 

event D i F - x y i k v - q T - F B B H Y G -

F A S D - J H i - L P 0 u B - As to result Gen H. H. 

Walker is ordered Y W F T - W S K T M T - B X z S -

Gq-XAmE-CHT-iu-AKMSAuPuVFLet me hear from you there- I will have need to 

see you to confer as to future action. The above 

is my telegram of yesterday which is repeated as 

requested. 

Jeffn Davis 

Official 

Burton Harrison 

Private Secy 

It is time now to tell you what I can about the success or lack of success which each side 

had with the cryptograms of the other side. I wish there were more information on this interesting subject than what I am about to present. Most of what sound information there 

is comes from a book by a man named J. Willard Brown, who served four full years in the 

Federal Army's Signal Corps. The book is entitled The Signal Corps, U.S.A., in t;he War of 

t;he Rebellion, published in Boston in 1896 by the U.S. Veteran Signal Corps Association. In 

his book Brown deals with the cryptanalytic success of both sides. First, let's see what the 

Union signalmen could do with rebel ciphers. Here are some statements he makes (p. 214): 

"The first deciphering of a rebel signal code of which I find any record was that made by Capt. 

J. S. Hall and Capt. R. A. Taylor, reported Nov. 25, 1862. Four days later, Maj. Myer wrote 

to Capt. Cushing, Chief Signal Officer, Army of the Potomac, not to permit it to become public 

'that we translate the signal messages of the rebel army.' 

April 9, 1863, Capt. Fisher, near Falmouth, reported that one of his officers had read a rebel 

message which proved that the rebels were in possession of our code. The next day he was informed that the rebel code taken (from) a rebel signal officer was identical with one taken previously at Yorktown. 

He received from Maj. Myer the following orders: 

'Send over your lines, from time to time, messages which, if it is in the power of the enemy 

to decipher them, will lead them to believe that we cannot get any clew to their signals.' 

'Send also occasionally messages untrue, in reference to imaginary military movements, as for 

instance--"The SilCth Corps is ordered to reinforce Keyes at Yorktown.'''" 

Undoubtedly, what we have here are references to the general cipher system used by the 

Confederates in their electric-telegraph communications, for note the expression "Send over 

your lines." This could hardly refer to visual communications. Here we also have very 

early instances, in telegraphic communications, of what we call cover and deception, i.e., 

employing certain ruses to try to hide the fact that enemy signals could be read, and to try to 

deceive him by sending spurious messages for him to read, hoping the fraud will not be detected. 

• I should wam you that it contains several errors! 

82 
• 

REF ID:A63860 

OONF'IBfiN:FfAfl 

Brown's account of Union cryptanalytic successes continues (p. 215): 

"In October, 1863, Capt. Merrill's party deciphered a code, and in November of the same year 

Capt. Thickstun and Capt. Marston deciphered another in Virginia. 

Lieut. Howgate and Lieut. Flook, in March, 1864, deciphered a code in the Western A:r:my, 

and at the same time Lieut. Benner found one at Alexandria, Virginia . 

Capt. Paul Babcock, ,Jr., then Chief Signal Officer, Department of the Cumberland, in a letter 

dated Chattanooga, Tennessee, April 26, 1864, transmitting a copy of the rebel signal code, says: 

'Capt. Cole and Lieut. Howgate, acting Signal Officers, occupy a station of communication and observation on White Oak Ridge at Ringgold, Ga .... On the 22nd inst. the 

rebels changed their code to the one enclosed, and on the same day the above-mentioned 

officers by untiring zeal and energy succeeded in translating the new code, and these 

officers have been ever since reading every message sent over the rebel lines. Many 

of these messages have furnished valuable information to the general commanding the 

department.' " 

The following is also from Brown (p. 279): 

"About the first of June (1864), Sergt. Colvin was stationed at Fort Strong, on Morris Island, 

with the several codes heretofore used by the rebels, for the purpose of reading the enemy 

signals if possible. For nearly two weeks nothing could be made out of their signals, but by 

persevering he finally succeeded in learning their codes. Messages were read by him from 

Beach Inlet, Battery Bee, and Fort Johnson. Gen. J. G. Foster, who had assumed command 

of the Department of the South, May 26th, was so much pleased with Sergt. Colvin's work, 

that in a letter addressed to Gen. Halleck, he recommended 'that he be rewarded by promotion to Lieutenant in the Signal Corps, or by a brevet or medal of honor.' This recommendation was subsequently acted upon, but, through congressional and official wrangling over appointments in the Corps, he was not commissioned until May 13, 1865, his commission dating 

from Feb. 14, 1865.'' 

(p. 281): 

"During the month, Sergt. Colvin added additional laurels to the fame he had earned as a successful interpreter of rebel signals. The enemy had adopted a new cipher for the transmission of important messages, and the labor of deciphering it devolved upon the sergeant. Continued watchfulness at last secured the desired result, and he was again able to translate the important dispatches of the enemy for the benefit of our commandants. The information thus gained 

was frequently of special value in our operations, and the peculiar ability exhibited by the sergeant led Gen. Foster once more to recommend his promotion." 

(p. 286) 

"About the same time an expedition under Gen. Potter was organized to act in conjunction 

with the navy in the vicinity of Bull's Bay. Lieut. Fisher was with this command, and by 

maintaining communications between the land and naval forces facilitated greatly the conjoined 

action of the command. Meanwhile every means was employed to intercept rebel messages. 

Sergt. Colvin, assigned to this particular duty, read all the messages within sight, and when the 

evacuation of Charleston was determined upon by the enemy, the first notification of the fact 

came in this way before the retreat had actually commenced. As a reward for conspicuous services rendered in this capacity, Capt. Merrill recommended that the sergeant be allowed a medal, 

his zeal, energy and labors fully warranting the honor. 

After the occupation of Charleston, communications was established by signals with Fort 

Strong, on Morris Island, Fort Johnson and James Island, Mount Pleasant, and Steynmeyer's 

Mills. A line was also opened with the position occupied by the troops on the south side of the 

Ashley river." 

With regard to Confederate reading of Union visual signals, Brown makes the following observations of considerable interest (p. 274): 

"The absolute necessity of using a cipher when signalling in the presence of the enemy was 

demonstrated during these autumn months by the ease with which the rebels read our messages. 

This led to the issuing of an order that all important messages should be sent in cipher. Among 

the multitude of messages intercepted by the enemy, the following were some of the more important ... " 

83 
REF ID:A63860 

CONF'IBEN'f'IAL 

Brown thereupon cites 25 such messages but he gives no indication whatever as to the source 

from which he obtained these examples or how he knew they had been intercepted. They all 

appear to be tactical messages sent by visual signals. 

In many of the cases cited by Brown it is difficult to tell whether wig-wag or electric telegraph messages were involved. But in one case (evacuation of Charleston), it is perfectly 

clear that visual messages were involved, when Brown says that Sgt. Colvin "read all the messages within sight." 

Further with regard to rebel cryptanalytic success with Union messages, Brown has this to 

say (p. 213): 

"The reports of Lieut. Frank Markoe, Signal Officer at Charleston, show that during the siege 

thousands of messages were sent from one post to another, and from outposts to headquarters, 

most of which could have been sent in no other way, and many were of great importance to the 

Confederate authorities. 

Lieut. Markoe says that he read nearly every message we sent. He was forewarned of our 

attack on the 18th of July, 1863. He adds regretfully, however, that through carelessness of 

the staff officers at headquarters it leaked out that he was reading our messages. Our officers 

then began to use the cipher disk. In August he intercepted the following message: 'Send me a 

copy of rebel code immediately, if you have one in your possession.' He therefore changed his 

code. . .. A little later our officers used a cipher which Lieut. Markoe says he was utterly unable to unravel.'' 

It is unfortunate that neither Lieutenant Markoe, the Confederate cryptanalyst, nor Brown, 

the Union signalman, tell us what sort of cipher this was that couldn't be unravelled. I assume that it was the Myer disk used properly, with a key phrase of some length and with successive letters, not whole words, being enciphered by successive letters of the key. But this 

is only an assumption and may be entirely erroneous. 

In the foregoing citations of cryptanalytic successes it is significant to note that visual messages were intercepted and read by both sides; second, that Confederate telegraphic messages 

protected by the Vigenere cipher were read by Union personnel whenever such messages were 

intercepted; and third, that USMTC telegraph messages protected by the route cipher, apparently intercepted occasionally, were never solved. Later I shall make some comments on 

this last statement, but at the moment let us note that technically the Vigenere cipher is theoretically much stronger than the route cipher, so that we have here an interesting situation, 

viz, the users of a technically inferior cryptosyst.em were able to read enemy messages protected 

by a technically superior one, but the users of a technically superior cryptosystem were not 

able to read enemy messages protected by a technically inferior one-a curious situation indeed. 

I can hardly close this lecture without citing a couple of messages which appear in nearly 

every account I've seen of the codes and ciphers of the Civil War. These are messages which 

were sent by President Lincoln under circumstances in which, allegedly, the usual cipher could 

not be or, at least was not, employed. The first of the two was sent on 25 November 1862 

from the White House to Major General Burnside, Falmouth, Virginia. The circumstances 

are so bizarre that if I merely presented the cipher message to you without some background I 

doubt if you would- believe me. And even after I've presented the background, I'm sure you 

won't know what to think. I, myself, don't really know whether to take the incident seriously 

or not. Let me quote from an account of it in the book by David Homer Bates, one of the 

first members of the USMTC, in his Lincoln in f:he Telegraph Office (Appleton-Century Co., 

New York, 1939, pp. 58-61): 

"During Burnside's Fredericksburg campaign at the end of 1862, the War Department operators discovered indications of an interloper on the wire leading to his headquarters at Aquia 

Creek. These indications consisted of an occasional irregular opening and closing of the circuit 

and once in a while strange signals, evidently not made by our own operators. It is proper to 

note that the characteristics of each Morse operator's sending are just as pronounced and as 

easily recognized as those of ordinary handwriting, so that when a message is transmitted over 

00NFIBEN'l'IAL 84 
,. 

.. 

REF ID:A63860 

-et>NPIB~IA.1. 

a wire, the identity of the sender may readily be known to any other operator within hearing 

who has ever worked with him. A somewhat similar means of personal identification occurs 

every day in the use of the telephone. 

"At the time referred to, therefore, we were certain that our wire had been tapped. In some way 

or other the Confederate operator learned that we were aware of his presence, and he then informed 

us that he was from Lee's army and had been on our wire for several days, and that, having 

learned all that he wanted to know, he was I.hen about to cut out and run. We gossiped with 

him for a while and then ceased to hear his signals and believed that he had gone. 

"We had taken measures, however, to discover his whereabouts by sending out linemen to patrol the line; but his tracks were well concealed, and it was only after the intruder had left that 

we found the place where our wire had been tapped. He had made the secret connection by 

means of fine silk-covered magnet wire, in such a manner as to conceal the joint almost entirely. 

Meantime, Burnside's cipher-operator was temporarily absent from his post, and we had recourse 

to a crude plan for concealing the text of telegrams to the Army of the Potomac, which we had 

followed on other somewhat similar occasions when we believed the addressee or operator at the 

distant point (not provided with the cipher-key) was particularly keen and alert. This plan consisted primarily of sending the message backward, the individual words being misspelled and 

otherwise garbled. We had practised on one or two dispatches to Burnside before the Confederate operator was discovered to be on the wire, and were pleased to get his prompt answers, 

couched also in similar outlandish language, which was, however, intelligible to us after a short 

study of the text in each case. Burnside and ourselves soon became quite expert in this homemade cipher game, as we all strove hard to clothe the dispatches in strange, uncouth garb. 

"In order to deceive the Confederate operator, however, we sent to Burnside a number of cipher messages, easy of translation, and which contained all sorts of bogus information for the 

purpose of misleading the enemy. Burnside or his operator at once surmised our purpose, and 

the general thereupon sent us in reply a lot of balderdash also calculated to deceive the uninitiated. 

"It was about this time that the following specially important despatch from Lincoln was filed 

for transmission: 

Executive Mansion, Washington, 

November 25, 1862. 11:30 AM. 

MAJOR-GENERAL BURNSIDE, Falmouth, Virginia: If I should be in boat off Aquia 

Creek at dark to-morrow (Wednesday) evening, could you, without inconvenience, meet me and 

pass an hour or two with me? 

A. Lincoln. 

"Although the Confederate operator had said good-by several days before, we were not sure 

he had actually left. We therefore put Lincoln's telegram in our home-made cipher, so that if 

the foreign operator were still on our wire, the message might not be readily made out by the 

enemy. At the same time extra precautions were taken by the Washington authorities to guard 

against any accident to the President while on his visit to Burnside. No record is now found 

of the actual text of this cipher-despatch, as finally prepared for transmission, but going back 

over it word for word, I believe the following is so nearly like it as to be called a true copy: 

Washington, D. C., November 25, 1862 

BURNSIDE, Falmouth, Virginia: Can Inn Ale me withe 2 oar our Ann pas Ann me :flesh ends 

N. V. Corn Inn out with U cud Inn heaven day nest Wed roe Moore Tom darkey hat Greek 

Why Hawk of Abbott Inn B chewed I if. BATES." 

This sort of subterfuge is hardly worthy of becoming embalmed in the official records of the 

war-and apparently it wasn't. But several years later, one of identical nature did become so 

embalmed, for the message appears on page 236, Vol. 45, of "Telegrams received by the Secretary of War": 

Hq. Armies of the U. S., City Point, Va., 

8:30 a. m., April 3, 1865 

TINKER, War Department: A. Lincoln its in fume a in hymn to start I army treating there 

possible if of cut too forward pushing is He is so all Richmond aunt confide is Andy evacuated 

Petersburg reports Grant morning this Washington Secretary War. BECKWITH. 

Both Plum and Bates cite the foregoing telegram. and their comments are interesting if not 

very illuminating. Plum says merely: "By reading the above backward with regard to the 

phonetics rather than the orthography, the meaning will be apparent." Bates says: 

85 CON.lt'IBBN't'IAL 
REF ID:A63860 

CONPIBBN'flAL 

"The probable reason for adopting this crude form was to insure its reaching its destination 

without attracting the special attention of watchful operators on the route of the City PointWashington wire, because at that crisis every one was on the Qui 1Jive for news from Grant's advancing army, and if the message had been sent in plain language, the important information 

it conveyed might have been overheard in its transmission and perhaps would have reached the 

general public in advance of its receipt by the War Department. 

"It is not necessary to give the translation of this cipher-message. To use a homely term, 

'.Any one can read it with his eyes shut.' In fact, the easiest way would be for one to shut the 

eyes and let some one else read it backward, not too slowly. The real wording then becomes 

plain." 

Can you imagine for one moment that a "cryptogram" of such simplicity could not be read 

at sight by any USMTC operator, even without having someone read it to him backward? 

Such a "cryptogram" is hardly worthy of a schoolboy's initial effort at preparing a secret message. But I assure you that I did not make this story up, nor did I compose the cryptogram. 

Ruminating upon what I have shown and told you about the cryptosystems used by both 

sides in the Civil War, do you get the feeling, as I do, that the cryptologic achievements of 

neither side can be said to add lustre to undoubt.edly great accomplishments on the battlefield? 

Perhaps this is a good place to make an appraisal of the cryptologic efficiency of each side. 

First, it is fair to say that we can hardly be impressed with the cryptosystems used by either 

side. The respective Signal Corps at first transmitt.ed by visual signals messages wholly in 

plain language; such messages were often intercepted and read straight away. Then both sides 

began enciphering such messages, the Signal Corps of the Federal Army using a cipher disk invented by the Chief Signal Officer, the Signal Corps of the Confederate Army using the Vigenere 

cipher. In both cases the use of cryptography for tactical messages was quite inept, although 

it seems that from time to time the Federal signalmen had better success with the Vigenereenciphered visual messages of the Confederate signalmen that the latter had with the disk.-

enciphered messages of the Union signalmen. 

With regard to the cryptosystem used by the Confederate Signal Corps, although there may 

initially have been cases in which monoalphabetic substitution alphabets were used, such 

alphabets were probably drawn up by agreement with the signal officers concerned and changed 

from time to time. Nowhere have I come across a statement that the Myer disk or something 

similar was used. In any event, messages transmitted by visual signals were read from time 

to time by Union signalmen, the record showing a number of cases in which the latter "worked 

out the rebel signal code"-meaning, of course, that the substitution alphabet involved was 

solved. When did the Confederate Signal Corps begin using the Vigenere cipher? The 

answer seems to be quite clear. In a letter dated 6 June 1888 from General J. H. Alexander 

(brother of General E. P.) to J. Willard Brown11 we find the following statements: 

"At the :first inauguration of the Signal Service in the Confederacy, I, having received in the 

first place the primary instruction from my brother, Gen. E. P.A., then a colonel on Beauregard's staff near the Stone Bridge at Manassas, was assigned the duty of preparing a confidential circular of instruction for the initiation of officers and men, in this branch. I did prepare 

it, in Richmond, in early spring, 1862, and surrendered the copy to Hon. James A. Seddon, the 

then Secretary of War at Richmond. It was issued in form of a small pamphlet. I had attached a table for compiling cipher dispatches-whU:h was printed with the rest of the matter-and 

the whok was issued confidentially t.o the officers newly appointed for signal duty. 12 

I have italicized the last sentence because I think that the "table for compiling cipher dispatches" can refer only to the Vigenere square table, for that and only that sort of table is 

even mentioned in accounts of the ciphers used by the Confederacy. One could, of course, 

wish that the writer had given some further details, but there are none. However, the statement about the table is sufficiently explicit to warrant the belief that it was General J. H. 

Alexander who officially introduced the Vigenere square into Confederate cryptography, al11 Op. cit., p. 206. 

12 My emphasis.-W.F.F. 

CONflBtlN'flA:L 86 
• 

REF ID:A63860 

GON.PIBBN'f'IAh 

though he may have obtained the idea from his brother, since he states that he "received in 

the first place the primary instruction from my brother." 

In the Federal Signal Corps it is quite possible that the polyalphabetic methods Myer cites 

in his Manual for using his cipher disk (changing the setting with successive words of a message) were used in some cases, because there are found in the record several instances in which 

the Confederate signalmen, successful with monoalphabetic encipherments, were completely 

baffted. One is warranted in the belief that it was not so much the complexities introduced by 

using a key word to encipher successive words of the plain text as it was the lack of training and 

experience in cryptanalysis which hampered Confederate signalmen who tried to solve such 

messages. In World War I a German Army system of somewhat similar nature was regularly 

solved by Allied cryptanalysts, but it must be remembered, in the first place, that by 1914 

the use of radio made it possible to intercept volumes of traffic entirely impossible to obtain 

before the advent of radiotelegraphy; and, in the second place, would-be cryptanalysts of both 

sides in the Civil War had nothing but native wit and intelligence to guide them in their work 

on intercepted messages, for there were, so far as the record goes, no training courses in cryptanalysis on either side, though there were courses in cryptography and signaling. It would 

seem to cryptanalysts of 1961, a century later, that native wit and intelligence nevertheless 

should have been sufficient to solve practically every message intercepted by either side, so 

simple and inefficient in usage do the cryptosystems employed by both sides appear today. 

No system employed by the Federals, either for tactical messages (Signal Corps transmissions) 

or strategic messages (USMTC transmissions) would long resist solution today, provided, of 

course, that a modicum of traffic were available for study. Although technically far less secure 

in actual practice than properly enciphered Vigenere messages, the route ciphers of the USMTC 

seem to have eluded the efforts of inexpert Confederate cryptanalysts. Ex-USMTC operators 

make the statement that none of their messages was ever solved and that the Confederates 

published intercepted messages in Southern newspapers in the hope that somebody would 

come forward with a solution; yet it must be remembered that those operators were Northerners 

who were very naturally interested in making the achievements of the Union operators, both in 

cryptography and in cryptanalysis, appear more spectacular than they really were. And it is 

probable that they wrote without having made a real effort to ascertain whether the Confederates did have any success. A "real effort" would have been a rather imposing undertaking then-as it still is, I fear. Now it must be presumed that if Confederate operators had 

succeeded in solving intercepted traffic of the USMTC they would have recorded the facts to 

their own credit. But in his seven volumes on the campaigns of Lee and his lieutenants, 

Douglas S. Freeman does not mention a single instance of interception and solution of telegraphic messages of the Union. Perhaps Freeman was seeking 100% confirmation, which is 

too much to expect in a field of such great secrecy. This failure of the Confederate cryptanalysts is the more astonishing when we know that copies of the USMTC cipher books were 

captured and that, therefore, they must have become aware of the nature of the route ciphers 

used by the USMTC, unless there was a lack of appreciation of the value of such captures and 

a failure to forward the books to the proper authorities, who could hand them over to their 

experts. In those books the USMTC route ciphers would have been seen in their naive simplicity, complicated only by the use of "arbitraries" or code equivalents, but hardly to the degree 

where all messages would be impossible to solve. It seems to me that there can be only four 

possible explanations for this failure to solve the USMTC route ciphers. Let us examine them 

in turn. 

First, it is possible that there was not enough intercept traffic to permit solution. But this 

is inadequate as an explanation. The route cipher is of such simplicity that "depth" is hardly 

an absolute requirement-a single message can be solved, and its intelligibility will be determined to a large degree by the number of "arbitraries" it contains. Where there are many, 

only the dim outlines of what is being conveyed by the message may become visible; where 

there are few or even none, the meaning of the messages becomes fairly evident. But the abundant records, although they contain many references to intercepts, fail to disclose even one 

87 
REF ID:A63860 

CONPlf>Ji!N't'IAL 

instance of solution of a USMTC message. Thus we are forced to conclude that it was not 

the lack of intercept traffic which accounts for lack of success by the Confederates with USMTC 

messages, but some other factor. 

Second, the lack of training in cryptanalysis of Confederate cryptanalysts might have been 

the reason why Confederate signalmen failed to solve the messages. This sounds plausible until 

we look into the matter with a critical spirit. Solution of route ciphers requires little training; 

native wit and intelligence should have been sufficient. The degree of intelligence possessed 

by Confederate officers and men was certainly as high as that of their Union counterparts who 

were up against a technically far superior cryptosystem, the Vigenere. We may safely conclude that it was not lack of native wit and intelligence that prevented them from solving 

messages enciphered by the USMTC route ciphers. 

Third, it is possible that Confederate high commanders were not interested in communication-intelligence operators or in gathering the fruits of such operations. Such an explanation 

seems on its face fatuous and wholely unacceptable. We know of the high estimate of value 

:field commanders placed upon the interception and solution of tactical messages transmitted by 

visual signaling; but an appreciation of the extraordinary advantages of learning the contents 

of enemy communications on the strategic level may have been lacking. My colleague, Mr. 

Fishel, thinks that "intelligence consciousness" and "intelligence sophistication" were of a very 

low order in the Union Army, and of a markedly lower order in the Confederate Anny. But to 

us, in 1961, to disregard the advantages of a possible reading of strategic messages seems almost incredible, and I am inclined to discount this sort of explanation. 

Fourth, it is possible that Confederate cryptanalysts were far more successful in their efforts 

to solve USMTC transmissions than present publicly available records indicate; that Confederate commanders obtained great advantages from their communication-intelligence operations; that they fully recognized the supreme necessity of keeping this fact and these advantages 

secret; and that the Confederate States Government adopted and enforced strict communication-intelligence security regulations, so that the truth concerning these matters has not yet 

emerged. Let it be noted in this connection that very little information can be found in the 

public domain today about Allied cryptanalytic successes during World War I; and were it not 

for the very intensive and extensive investigations in the matter of the Japanese attack on Pearl 

Harbor on 7 December 1941, very little, if any, information would be known to the public about 

British and American successes in communication intelligence during World War II. Immediately following the capture of Richmond and before Confederate records could be removed 

to a safe place, a great fire broke out and practically all those records were destroyed. It is 

possible that this is one of the reasons why the records of their communication-intelligence 

successes have never come to light. But it is also possible that Confederate cryptanalysts kept 

their secrets to themselves. We know that the records possessed or taken by certain Confederate leaders have been gone over with great care and attention, but what happened to those 

retained by other Confederate leaders such as the Secretary of War Seddon, or his predecessor 

Judah P. Benjamin, who later became Secretary of State, and others? Here is a fascinating 

speculation and one which might well repay careful, painstaking research in the voluminous 

records of our National Archives. I shall leave the delving into those records to some of you 

young and aspiring professional cryptanalysts who may be interested in undertaking such a 

piece of research. With this thought I bring this lecture to its close. 

88 
REF ID:A63860 

Lecture V 

For a half century following the close of the Civil War, cryptology in the United States 

enjoyed a period of hibernation from which it awoke at long last about 1914, not refreshed, 

as did Rip Van Winkle, but weaker. This is perhaps understandable if we take into account 

the fact that the United States was able to enjoy a long era of peace, broken only briefly by 

the short war with Spain in 1898. For over three decades there was little or no need for cryptography in the United States Government, except for the communications of the Department 

of State. The military and naval services apparently felt that in time of peace there was no 

need for either cryptography or cryptanalysis, and since it looked as though the U.S. was 

going to enjoy peace for a long, an indefinitely long time, those services did not think it necessary or desirable even to engage in theoretical cryptologic studies. Of course, the War Department and the Army still had those route ciphers and cipher disks described in the preceding 

lecture; the Navy Department and the Navy had cipher disks for producing simple monoalphabetic ciphers; and the Department of State had a code more-or-less specifically designed 

for its communications. Separated from Europe by the broad Atlantic, and mindful of General 

Washington's policy of noninvolvement in the problems of European diplomacy, America 

followed the traditional and easy course of isolationism. The quarrels among the countries in 

Europe were none of our business, and America turned its back to them for a half century, uninterested and unconcerned. 

There was, however, in this long hibernating period in U.S. cryptology one episode of particular interest. It concerned a Presidential election in which the circumstances paralleled the 

election of 1960, when the very small popular-vote majority of the Democratic candidate suggested a possible upset in the electoral college voting. The episode to which I refer here occurred nearly a century ago, in the Presidential election of 1876, in which Democratic candidate Samuel J. Tilden was pitted against Republican candidate Rutherford B. Hayes. On the 

basis of early evening election returns Tilden seemed to be easily the winner. Indeed, just before going to bed on election night, 8 November 1876, Hayes conceded the election to Tilden, 

and the newspapers next morning followed this lead and reported a Tilden victory. But when 

:final tallies began coming in they showed that the closeness of the popular vote made Tilden's 

victory not so sure as his supporters had calculated, and they therefore began to become apprehensive about their candidate's victory. Their apprehensions were valid because of our 

peculiar system of electing a president, peculiar because it is the electoral and not the popular 

vote which det.erroines who is to be the next occupant of the White House as President. Two 

days after the people had voted, it became clear that Tilden would have 184 electoral votes, 

just one vote short of insuring victory, whereas Hayes would have only 163, thus needing 22 

more. The TildE•n supporters began a frantic campaign to get tiiat one additional vote they 

needed, and they didn't hesitate to try every possible ruse to obtain it, including bribery, a 

rather serious piece of business and one obviously requiring a good deal of secrecy, especially 

in communicatio:c.s. Of course, many telegrams had to be exchanged between the Tilden headquarters in New York City and confidential agents who had to be sent to certain states where 

one or more electoral votes could perhaps be purchased; telegrams also had to be exchanged 

among those secl'l~t agents in the :field. About 400 telegrams were exchanged and some 200 of 

these were in cr:rptographic form. Communication difficulties caused two almost consummated bribery deals to fall through; and a third deal failed because the electors proved to be 

honest Republica1s not susceptible to monetary temptation. The existence of these telegrams, 

however, remained unknown to the public for months. We shall come to them later. 

Despite the efforts of the Tilden supporters, the outcome of the election remained in doubt 

because four stahs, Florida, South Carolina, Louisiana and Oregon, each sent two groups of 

89 OON.PIBBffflAL 
REF ID:A63860 

electors, an event not foreseen or provided for in the Constitution. A crisis arose and the 

country seemed to be on the verge of another civil war. By an Act of 29 January 1877, Congress 

created a special electoral commission to investigate and decide upon the matter of the disputed electoral votes in the four states. Recounts of votes in certain election precincts were 

made, sometimes aided by soldiers of the Federal Army. The commission voted in favor of 

the Hayes electors in each case, and having obtained the needed 22 electoral votes, Hayes 

entered the White House. 

It was only some months afterward that the telegrams to which I have referred were brought 

to light, and a situation arose which Congress felt it had to look into. Somehow or other, in 

the summer of 1878, copies of those telegrams had come into the possession of a Republican 

newspaper in New York, The Tribune. Interested only in ascertaining the truth, the editor 

put two members of his staff on the job, and they succeeded in solving those telegrams which 

were in cipher. 

Various books dealing with the political aspects of his intriguing story are available in 

public libraries, but those of you who are interested only in its cryptologic aspects will :find 

excellent material in the following four documents: 

(1) "The Cipher Dispatches", The New York Tribune, Extra No. 44, New York, (14 January) 

1879. 

(2) Hassard, John R. G., "Cryptography in Politics,'' The North American Reuiew, Vol CXXVIII, 

No. 268, March 1879, pp 315-325. 

(3) Holden, Edward S., The Cipher Dispatches, New York, 1879. 

(4) U. S. House Miscellaneous Documents, Vol 5, 45th Congress, 3rd Session, 1878-79. 

The last-mentioned item, that put out by the Congressional House Committee which had 

been designated to conduct the investigation (and which was named "The Select Committee 

on alleged frauds in the Presidential Election of 1876"), is of special interest. In the course 

of the investigation, the Committee solicited the technical assistance of Professor Edward S. 

Holden, of the United States Naval Observatory in Washington, the author of the third item 

listed above, who I believe was a captain in the Navy and had specialized in mathematics. 

The Tribune had brought him into the picture by asking his help when solution seemed hopeless, 

but it turned out that Mr. John R. G. Hassard, the chief of The Tribune staff, and his colleague, 

Colonel William M. Grosvenor, also of that staff, solved the ciphers independently and, in fact, 

shortly before Prof. Holden solved them, although it was the latter that the Congressional Committee called upon to explain matters, as would only be natural under the circumstances. 

Professor Holden's testimony, in which he set forth his solution of the nearly 200 cryptograms 

entered in evidence, is presented in the form of a letter to the Committee, dated 21 February 

1879. In it he described and explained all the cryptosystems used, together with their keys 

and full details of their application. In that letter, Professor Holden makes the following 

statement: "By September 7, 1878, I was in possession of a rule by which any key to the most 

difficult and ingenious of these [ciphers] could infallibly be found." Most of the ciphers involved word transpositions and Holden worked out the keys but in this he had been anticipated 

by the Tribune cryptanalysts. There were in all 10 different keys, two for messages of 10, 15, 

. . . words, up to and including two for messages of 30 words. On the opposite page will be 

found the complete "Table of Keys." 

You may be wondering why there are two transposition keys for each length of message 

from 10 to 30 words, in multiples of 5. The two keys constituting a pair are related to each 

other, that is, they bear a relationship which Mr. Hassard, one of the Tribune cryptanalysts, 

termed "correlative," but which we now would call an "encipher-decipher" or a "verse-inverse" 

relationship. Either sequence of a correlative pair of sequences may be used to encipher a 

message; the other can then be used to decipher the message. For example, key III consists of the following series of numbers: 8--4-1-7-13 .•. , etc., and the correlative, key IV, is 

3-7-12-2-6 ... , etc. A cipher message of 15 words can be deciphered either by (1) numberCQHRBBN'f'fAL 90 
REF ID:A63860 

TABLE OF KEYS 

10 Words 15 Words 20 Words 25 Words 30 Words 

I II III IV v VI VII VIII IX x 

9 4 8 3 6 12 6 18 17 4 

3 7 4 7 9 18 12 12 30 26 

6 2 1 12 3 3 23 6 26 23 

1 9 7 2 5 5 18 25 1 15 

10 6 13 6 4 4 10 14 11 8 

5 3 5 8 13 1 3 1 20 27 

2 8 2 4 14 20 17 16 25 16 

7 10 6 1 20 16 20 11 5 30 

4 1 11 11 19 2 15 21 10 24 

8 5 14 15 12 19 19 5 29 9 

9 9 17 13 8 15 27 5 

3 14 1 10 2 2 19 19 

15 5 11 6 24 17 28 17 

12 10 15 7 5 24 24 25 

10 13 18 14 11 9 4 22 

8 17 7 22 7 28 

16 11 13 7 13 1 

2 15 1 4 18 18 

10 9 25 10 12 12 

7 8 22 8 22 6 

9 23 21 21 

16 20 15 20 

21 3 3 29 

14 13 9 14 

4 19 14 7 

2 3 

6 11 

16 13 

23 10 

8 2 

Figure 70. 

ing its words consecutively and then assembling the words in the other 8-4-1-7-13, or by (2) 

writing the sequence 3-7-12-2-6 ... above the words of the cipher message and then assembling the numbered words according to the sequence 1-2-3-4-5 . . . . Thus, there were, in 

reality, not ten different transposition keys but only five. In the case of each pair of keys, one 

of them must have been the basic sequence, the other the inverse of it, or at least some derivative thereof. 

I suspect that the basic or "verse" sequences of numbers were not drawn up at random but 

were derived from words or phrases; and I think that they were the odd-numbered ones because, 

as you will notice, it is in the odd-numbered keys that the positions of seq_uent digUs reflect 

the presence of an underlying key word or phrase; this is not true in the even-numbered keys. 

I have not seriously attempted to reconstruct the key words, but perhaps some of you may 

like to try and will succeed in doing so. 

In addition to transposition, this system involved the use of "arbitraries" to represent certain 

words, the names of important persons and places, numerals, etc. There were also a few nulls. 

Professor Holden adds some comments about this system which are worth quoting: 

"The essence of this ingenious and novel system consists in taking apart a sentence written in 

plain English (dismembering it, as it were) and again writing all the words in a new order, in 

which they make no sense. The problem of deciphering it consists in determining the order 

according to which the words of the cipher should be written in order to produce the original 

message. 

91 C6ffti'ft>BN I IAL 
REF ID:A63860 

OONPIBBN'l'IM:i 

"There is one way, and only one way, in which the general problem can be solved, and that 

is to take two messages, A and B, of the same number of words, and to number the words in each; 

then to arrange message A with its words in an order which will make sense, and to arrange the 

words of message B in the same order. There will be one order-and only one--in which the 

two messages will simultaneously make sense. This is the key." 

Here, in a nutshell, we find the basic theory of solving transposition ciphers by anagramming 

messages of the same length, explained in a most succinct manner. 

It appears that Professor Holden, clever as he was, did not note the verse-inverse relation 

in each pair of sequences, or if he did, he failed to mention it in his testimony. However, 

Hassard [2] specifically points this out. 

There were enough messages in this system to make it possible to solve code words used, 

as well as to recognize a few nulls which were occasionally added to complicate matters. Hence, 

the most complicated of the cryptosystems involved in this bizarre political episode were 

solved. 

Another system used by the conspirators employed a biliteral substitution, that is, one in 

which a pair of cipher letters represents a single letter. This substitution was based upon a 

10 X 10 checkerboard. Apparently neither Professor Holden nor the Tribune cryptanalysts 

recognized the latter principle, nor did they find that the coordinates of the checkerboard 

employed a key phrase, nor did they realize that the same checkerboard, with numerical coordinates, was used for a numerical substitution alphabet in which pairs of digits represent 

letters of the alphabet. 

Here are two of the messages exchanged by the conspirators, one in the letter cipher, the 

other in the :figure cipher. The messages are long enough for solution. Try to solve them, 

reconstruct the matrix and :find the key phrase from which the coordinates of the matrix were 

derived. It should amuse you by its appropriateness. 

The message in letter cipher is as follows: 

Jacksonville, Nov. 16 (1876) 

Geo. R Raney, Tallahassee: 

PP YY EM NS HY YY PI MA SH NS YY SS IT EP AA EN SH NS 

SE US SH NS MM PI YY SN PP YE AA PI EI SS YE SH AI NS ~~~rr~~~~YEnAAeIT~~n&n 

PI NS YY SS IT EM EI PI MM EI SS EI IT EI SS IT EI EP 

YY PE EI AA SS IM AA YE SP NS YY IA NS SS EI SS MM PP 

NS PI NS SN PI NS IM IM YY IT EM YY SS PE IT MN NS YY 

SS IT SP IT PE EP PP MA AA IT PI IT L'Engle goes 

up tomorrow. 

(Signed) Daniel 

The example in :figure cipher is as follows: 

Jacksonville, Nov. 17 (1876) 

S. Pasco and E. M. L'Engle: 

84 55 84 25 93 34 82 31 31 75 93 82 77 33 55 52 93 20 

90 66 77 65 33 84 63 31 31 93 20 82 33 66 52 48 44 55 

42 82 48 89 42 93 31 82 66 75 31 93 

(Signed) Daniel 

There were several other systems involved in this episode of political skullduggery, but I am 

going to have to pass them by because they hardly deserve attention in this brief history. I 

do, however, want to call your attention to the very close resemblance between the word92 
• 

REF ID:A63860 

transposition ciphers characterized by Professor Holden as the "most difficult and ingenious" 

of the ciphers he solved, and the USMTC route ciphers described in the preceding lecture. 

Yet, not only he but also the Tribune amateur cryptanalysts solved those ciphers without too 

much difficulty, even though they were technically more complex. I think their work on the 

Tilden ciphers clearly confirms my own appraisal of the weakness of the route ciphers used by 

the USMTC in the Civil War. 

After this digression into the rea1m of what may be called politica1 cryptology, let us now 

go on with our military cryptologic history. I have already told you that the Department of 

State used a code for cryptographic communications in the years following the Civil War, but 

I do not know what it was like. It may even have been an adapation of some commerical 

code. But in an article entitled "Secret Writing," which appeared in Cent;ury Magazine, Vol. 

LXXXV, November 1912, No. 1, a man named John H. Haswell, apparently at that time a 

code clerk in the Department, referred to a new code of the department in the following terms: 

"The cipher of the Department of State is the most modern of all in the service of the Government. It embraces the valuable features of its predecessors and the merits of the latest inventions. Being used for every species of diplomatic correspondence, it is necessarily copious and 

unrestricted in its capabilities, but at the same time it is economic in its terms of expression. It 

is simple and speedy in its operation, but so ingenious as to secure absolute secrecy. The construction of this cipher, like many ingenious devices whose operations appear simple to the eye 

but are difficult to explain in writing, would actually require the key to be furnished for the purpose of an intelligible description of it." 

Only four years later a certain telegraph operator and code clerk of the State Department 

proved how vulnerable the Department's system of enciphered code really was. His name was 

Herbert 0. Yardley (Fig. 71) and many of you may know a bit about him as the author of a 

famous or infamous book (depending upon whose side you're on) entitled The American Black 

Chamber, published in Indianapolis by the Bobbs-Merrill Co. in 1931. So far as I know it is 

the only book which cannot legally be reprinted in the United States because a specia1 law 

passed in 1934 makes it a criminal offense to do so. That is quite a story in itself, but I cannot tell it now. If you happen to own a copy of the first and only American edition, don't 

let it get away from you, because you can only obtain another copy of it by a more-or-less 

"under the table" deal; but you may be able to purchase a British edition, or a translation in 

French, in Japanese, or in other languages, for the book was sensational. But to return to 

that State Department cryptosystem, which was considered by Haswell as giving absolute 

secrecy and which was readily solved by Yardley, here is what appears on the cover page of 

Yardley's 21-page typewritten analysis and solution of the system: 

THEORY AND PRACTICE OF ENCIPHERED CODE 

State Department Problems 

I, II, and III 

Note: The following was written in March 1916 and, so far as I can learn, is the first successful 

attempt to solve a problem in enciphered code. 

H. 0. Yardley 

Yardley was quite wrong in thinking that his was the :first successful attempt to solve a 

problem in enciphered code, for in Europe more complicated cases were often solved, and I 

imagine that European cryptanalysts could have read, and perhaps did read, State Department 

messages as a more or less routine matter. I think I am warranted in assuming that what I 

have just said is true because, in Europe, cryptanalytic studies were going on apace during the 

years of American neglect of such studies. The turning point from neglect to a renaissance 

of interest in cryptologic studies in Europe is said by some authorities to have been about the 

year 1880; but we must confine ourselves for the most part to developments in America, in 

order to keep this lecture within bounds of what can be told within a limited time. 

In our Navy it seems that simple monoalphabetic ciphers continued in use until the middle 

of the eighties, when several naval officers were designated to prepare a more suitable system, 

93 
REF ID:A63860 

OONFIBEN't'IMA 

Figure 71. 

based upon a code particularly designed for naval communications. The system they worked 

out was embodied in a very large codebook, 18" long, 12" wide and 2" thick, which had the 

official title The U. S. Navy Secret Code. There was also an accompanying but separate cipher 

book, almost as large, and designated as The Book of Key Words. In addition to these was a 

third large book called General Geographical, Tabks. The system was placed into effect on 1 

December 1887. Later I will show you a most historic message sent in that system of secret 

communication, which today impresses one as being extraordinarily clumsy and slow. 

In our Anny, in the middle eighties, a code was also prepared. It is no pleasure to have to 

tell you that its composition and format hardly shed laurels upon those responsible for its reproduction, because it was merely a simple and acknowledged adaptation of a commercially 

available small code for use by the general public, first published in 1870 with the title Telegraphic Code to Ensure Secresy in the Transmission of Telegrams. It had been compiled by the 

Secretary of the French Trans-Atlantic Telegraph Company, a man named Robert Slater, and 

it became known everywhere as "Slater's Code." As to the nature of the code, I will quote 

from Slater's own "Short explanation of the mode of using this work," in a sort of preface to 

the 2nd Edition: 

"It is a numbered Telegraphic Dictionary of the English language, of which each word bears 

a distinctive No. (from 00001 to 25000, with exactly 100 words per page), and the method of 

using it is by an interchange of Nos., in accordance with a private understanding between correspondents that a further No. is to be added to or deducted from the number in the code, of the 

word telegraphed or written, to indicate the real-word intended, thus a "Symbolic" or "Dummy 

Word" is telegraphed, the meaning of which can only be read by those who have the key to the 

secret of how many should be added to or deducted from the number in the Code, of the "Dummy 

Word" to find the word meant." (Punctuation as in the original). 

Here we have a sentence of 116 words. Though it is rather long and a bit murky, I think 

you will gather its import. The system as thus far described is what we now call the additive 

or subtractive method. But in the detailed instructions Slater goes one step further and suggets that instead of telegraphing the code number resulting from addition or subtraction of a 

94 
.. 

.. 

REF ID:A63860 

key number, the word standing alongside the sum (or difference) of the mathematical operation be sent as the telegraphic code word. Slater's code must have met with popular acclaim 

because by 1906 it was in its :fifth edition. A copy of the second edition (1870), is in my collection. As for a copy of the very first edition, not even the Library of Congress has one, 

it's that scarce. 

To get on with the story, in 1885 the War Department published an adaptation of Slater's 

Code for its use and the use of the Army. Here is a picture of its title page, the only difference between it and that of Slater's Code being in the spelling of the wozd "secrecy," as you 

can easily see in the picture I show you next (Fig. 72). It would appear that the "compiler" 

of this code, Col. Gregory, was just a bit deficient in imagination, because not only did he merely 

TELEGRAPHIC 

CODE, 

T<> 1:..,.i-nu: 

SECRESY 

IX Tiii-: 

'£r11nsmissian of <telegrams. 

8Y 

ROBERT SLATER, 

SECRETARY OF THE 

S«Ule tlu Ct.1/J/e Transallanli'lue Franfit1is, Li111ileli . 

(Fr~"'" AtlirnlU' T;/qnlpA Co,,,Ja11y). 

--

LONDON: 

PRINTED AND PUBLISHED DY 

W. R. GRAY, 

19A, CHANGE ALLEY, CORNHILL. 

1870. 

TELEGIL\PlllU CODE 

TO 

I NRrHE SECRECY 

IN TllK 

TRANSlllSSIOX OF TELEGRAMS. 

BY AUTHORITY or THE SECRETARY or W.ll. 

lleriaed and adapt9'.I for apecial ,,,. from tfl• p1161it:atiall 

of RoHrt Slater, S.Cretarr of th• French Atlantff: 

Telagraph Cornpany, under direction of f6e 

L1t:11tenant-tleneral of the Army 

lh" .J. r. cmEUOKY 

LIF.l Tt::SA:S r-COLONKL ANI> .t.. D. C, 

lHH[). 

\\" A8HING1'0N: 

oov•:R:SMF'T r1u:sT1:so orr1c:s. 

1 ....... ; • 

Figure 12. 

borrow the basic idea and format of Slater's Code, but even when it came to explaining and 

giving examples of enciphering the code groups, the Colonel used not only the identical rules 

but also the very same wording and even the very same type of examples of transformations 

that are found in Slater's original. Let me show an example in Slater's code side by side with 

the same example in Gregory's: 

95 
CONflBtlN'flAL 

.IXAll l'LllS. 

BXAKPLB L 

711 QuNir is llrt supremt fJtJwer ;,, th Eealm. 

Add any number below ZSCJOO (say, for instance,) 5555 to 

the numben opposite to those words 1t is desired to transmit. 

Where the result exceeds ZSCJOO, deduct that number, or, m 

other words, commence the alphabet again. 

WOid ID be No. In Plus trammilled. V-\111luy 5555· :c=t; 

1"l1e a313 a7868 Bounteous 

Queen .. 11!o95 a]650 pu=g 12370 17m the az313 a7 tiounteom 

supren1e ar9u a~ biognphy ~wer 170 a u transparent m 11426 I= poSed tl1e a2313 a7 boilnteous 

Re.ilm 18419 a3974 yoke 

The message being tnnsmitted :-

BollRletnls ftlldge Juri,hiag !HnmlMJllS !Jiogralli,Y 

transparent poSlll IJollnlMJllS yoh, 

the receiver reYeneS the opemtion, acldine asaoo to the 

number where it is below that to be deducted. 

I Wanl I No 1a rec:ei....S. Vocabular)o. 

Bounteous oa868 1a313 The 

wedi.oe a]650 18095 fll!een 

purifymi: ::aa 12370 II 

liounteou1 az313 the 

biography 

:~ ar95~ supreme lra111parent 1705 

pOled 1691!1 11426 ~-ID 

bOunteous oaS6S az313 the 

JOke a397+ 18419 Realm 

REF ID:A63860 

VI 

l:XA:\lPLE I. 

1ra1· i• a p1ini11iment u:lr~rta/ dntl~ i• the mu.rlmum. 

Add any number below 25000 (any, for instance, 33:13) 

to tho numbers oppoaito to thoao wonla it is 1lesired to 

transmit. Whero the n-anlt e:.:oeede l!liOOO, 1le1luct that 

number, or, in other wo1,le, comml'neo the alphabet 

again. 

Wonl to bo Number in Ro•pn•sentiug transmitted. vocabtllary Pine 3:i:J3. i11 \'oeabnlary. 

Wnr :!:J724 270;;7 Harker IS 12:17:1 t:r.111; O\'Rtinn a 00001 00:1:14 cairn 

11unial1111<'11t 171!'.13 2l:l'.!li 11011si11g whereof 2:1887 ~7~ be;..retting <leatb O&»l ooa:i:; lreqm•nt is l~'i:i 15706 o\·ation 

the ~l'.!7 2."lfillO ngnpo• maxmuun Hua:.! 17:16j 11rigg1~h 

The messag<' l1eing transmitted rerul11-

Barl:er omtioa cairn 1oai11g begetting frequent OMtion 

agape priggHl, 

the receiver roversea tile OJN!rabon, a<l1ling 2dOOll to the 

n11ml11.•r \Vbero 1t iK bl'low that to bu 1leducted. 

Wonl 

fteeh·eJl· 

Barker 

ovation 

cairn 

&011ai11g 

begetting 

Cre11nent 

ovatlnn 

aga(!41 

prlin,rillh 

Number i11 I~· . '1 Re1)re11Bnting \'ocabnlary .... mna 3:JJ:l.

1

in \·oeab1dary. 

020:.7 

l:i7f'fi 

0:1:131 

~1~a; 

O:!'d:.!U 

01.1:;:15 

1:.;111; 

00fi60 

173tlii 

I \~r 

I 1111nishment 

\\ bl•rc•nf 

I 

11entb 18 

the 

ruaxi11111m 

Figure 73. 

You will note that Col. Gregory just couldn't use the same text for his examples of encipherment that Slater used, which was: "The Queen is the supreme power in the Realm." Instead he used the enigmatic text: "Wax is a punishment whereof death is the maximum." 1 

All the other methods and examples of encipherment in the two codes are practically identical. Colonel Gregory gives credit in the following terms to a civilian aide in his great work: 

"The labor of compiling the new vocabulary has been performed by Mr. W. G. Spottswood." 

What did the latter do? Well, Mr. Spottswood's work consisted in casting out from Slater's 

list such words as ABALIENATE and ABANDONEE and replacing them with such words as 

ABATEMENT and ABATIS. This sort of work must indeed have been arduous. I'm sorry to 

appear to be so critical of the performance of my predecessors in the construction of codes 

and code systems for Wax Department and Army usage, but I feel sure you will agree that 

more imagination and ingenuity could have been employed than were used by Colonel Gregory 

and Mr. Spottswood. 

11 wonder what that sentence means. It sounds sort of "anti-American" to me. Punishment to whom? 

To the soldiers and sailors and airmen who defend our country? If not to them, then to whom? To the 

people of a whole nation :fighting for liberty? I just don't understand the sentence. Do you? 

96 

.. 
REF ID:A63860 

Col. Gregory prepared a confidential letter addressed to Lieut. General Sheridan, "Commanding Army of the U.S.," to explain the advantages of the new code. But in this letter 

Col. Gregory quotes very largely from Holden's little brochure [3] and deals almost solely 

with the ways in which additional security may be gained by changing the additives to the 

code numbers in Slater's Code. For example, for all messages sent in January add 111; for 

all messages sent in February add 222, in March 333, etc. Another suggested way: "Send 

out a simple message in ordinary English: Add 1437 to all ciphers until further orders." 

Believe it or not, this was the code that the War Department and the Army used during 

the Spanish-American War. It was apparently used with a simple additive, because in a copy 

in my collection the additive is written on the inside of the front cover. It is 777; perhaps it 

was the additive for the month of July, but the number 777 was written in ink, so it may have 

been the permanent additive for the whole of the war. In pages 41-42 of The American Black 

Chamber the author throws an interesting sidelight on this code system: 

"The compilation of codes and ciphers was, by General Orders, a Signal Corps function. but 

the war (1917) revealed the unpreparedness of this department in the United States. How much 

so is indicated by a talk I had with a high officer of the Signal Corps who had just been appointed 

a military attache to an Allied country. It was not intended that attaches should actually encode and decode their own telegrams, but as a part of an intelligence course they were required 

to have a superficial knowledge of both processes in order that they might appreciate the importance of certain precautions enforced in safeguarding our communications. 

When the new attache, a veteran of the old Army, appeared, I handed him a brochure and 

rapidly went over some of our methods of secret communications. To appreciate his attitude, 

the reader should understand that the so-called additive or subtractive method for garbling a 

code telegram (used during the Spanish-American War) is about as effective for maintaining 

secrecy as the simple substitution cipher which as children we read in Poe's The Gold Bug. 

He listened impatiently, then growled: "That's a lot of nonsense. Whoever heard of going 

to all that trouble? During the Spanish-American War we didn't do all those things. We just 

added the figure 1898 to all our figure code words, and the Spaniards never did find out about it." 

Although The American Black Chamber abounds with exaggerations and distortions, what the 

author tells about the inadequacies of United States codes and ciphers in the years just before our entry into World War I are true enough, and Yardley's impatience and satiric comments in this regard, it grieves me to say, are unfortunately fully warranted. 

During or perhaps shortly after the end of the Spanish-American War, the War Department 

must have begun to realize that there were shortcomings in the code based upon Slater's Code, 

the one which was in current usage and upon which I have already dwelt. On 16 January 

1898 the publication of a new War Department Telegraphic Code was authorized by General 

Orders No. 9. The code was to be prepared under the direction of General A. W. Greely, 

then Chief Signal Officer of the Army. The cited General Order makes it quite clear that the 

War Department version of Slater's Code was still in use, but the Western Union Telegraphic 

Code was to be used in connection with Slater's until the new War Department Code was 

completed, which apparently was ready in December 1899, when Slater's was withdrawn from 

use with this statement in General Orders No. 203: "By direction of the Secretary of War, 

the Tekgraphic Code t,o Insure Secrecy in 'the Transmission of Telegrams, will on and after January 

15, 1900, only be used for correspondence in such cases as may be specially ordered by the 

Secretary of War." On 12 December 1899 the new War Department Code was issued. Here 

is a picture of its title page (Fig. 74). It comprised a specially-compiled list of tE..bles, words, 

phrases and sentences to which code numbers and code words were assigned for specific use in 

War Department and Army communications. The code numbers began with 78201 and went 

to 95286; the accompanying code words were foreign, outlandishly unusual real words, and 

artificial words, beginning with KOPERKIES, KOPERKLEURS, KOPERMOLEN, etc., etc., down 

through the L's, M's and ending with words such as NAZWELGEN, NEANTHE, NEAPELGELB, etc., 

etc. You may wish to know why the code numbers didn't begin with 00000 and go to 99999; 

or why the code groups began with K and went for thousands and thousands of words down 

to N. The answer is that this brand new War Department Telegraphic Code was to be used, 

97 OONflBBN'ft:AL 
REF ID:A63860 

OO:NFIBBN'f'IAL 

as Slater's Code was used, in conjunction with the Western Union Telegraphic Code, a code of 

78,200 groups beginning with numerical code groups 00000 accompanied by literal code words 

beginning with BEERKAR, BEERKARREN, BEERMELD .•. and going to KOOTJONGEN, KOOTKRUID, 

KOOTSPEL. Here is a picture of a typical page in this code (Fig. 75). 

WAR DEPARTMENT 

TELEGRAPHIC CODE. 

um t "'ilb"4AI UHlC tll: u ' .\ 

\'UM.blil.U l!'I' \JltUH. 01 lHI. HuM>R"""-' l-uHU Ru.u 

.,l1KlrAkY Ill \\AK 

\9A~HINGTON 

Figure 74. 

The introduction to this code explains this puzzling fact. 

Figure 75. 

"Through lack of time it has been impossible to incorporate in the War Department Telegraphic 

Code all desirable phrases, and in consequence the first 471 pages of the Western Union Telegraphic 

Code now in use by the Army will continue in use as a supplementary code. This affords the Army 

the telegraphic use of 100,000 code words, of which numbers 1 to 78,201, inclusive, are in the 

Western Union Tekgraphic Code and numbers 78,201to100,000 are in the War Department Tekgraphic Code." 

It thus becomes clear that for several years the new War Department Code was to be used 

in conjunction with the commercially available large Western Union Telegraphic Code. This 

was stated to be for the purpose of economy. For secrecy, the additive or subtractive method 

was to be used. The futility of such an old and simple method for achieving communication 

security needs no comment. I wish there were time to read you the instructions in that new 

War Department Telegraphic Code as regards the use of these ciphers for secrecy. They are 

practically the same as those in the 1885 version of Slater's Code and are unbelievably futile, 

but what else could be expected when cryptology is relegated to a position in military science 

far inferior to that of teaching the use of a rifle or bayonet, subjects which are taught, as a 

rule, by experts? Why was cryptology left to inexperienced amateurs during all those years? 

Was it stupidity? No, just a lack of appreciation of the importance of secure communications 

in military operations-and a lack of enough people with the requisite know-how. 

How long this combination of two codes continued to be used I don't know. Sometime 

during the years 1900 to 1915 this absurd system must have proved itself entirely unsatisfactory, for in 1915 another brand new War Department Telegraph Code was put out, under direction of Brigadier General George P. Scriven, the Chief Signal Officer of the Army who succeeded Greeley. Here is a picture of its title page (Fig. 76). The book bears no security 

98 
REF ID:A63860 

WAR DEPARTMENT 

TELEGRAPH CODE 

1915 

PREPARED UNDER THE DIRECTION OF TIIE 

CHIEF SIGNAL omCER OF TIIE AR.'llY 

Pu&l11bed Ly aut:hont)' al 1M Secnl•IJ' el War 

WA!HINC'l'ON 

GOVERNMENT PRINTING OFF1CE 

1915 

Figure '76. 

~)l!l 

Ui'Tl\., 

:m IKEDA .... , ... •tKEGt: 

:HOIKEllP 

31llKl!lll 

31111Lt'hl 

:11:1 IKIVI :Slollht.'\h. 

:llllKl.I'\ 

311 IKl!!iill 

lltllH~ 311 ....... •IS.El.\ m1xr.11 

Ullht'BA 

UlllHI 

:w ......... DGIKFGF 

321' IKFllG 

:11~i11 

DI IS.Fl.I 131 IKF•I. :DllK.FOI(, 

:m IKFPH 

B!llHI: 

31111 IKFCT 

~1~s~·, 

'UllKP::l.W' 

:StU Iii.FIX Mll.1.0,U. 

:HI Iii.Gii• 

l::lfll 

NIKLHll 

'itl 111.G.a.J 14'1' lllGli.h 

...... a"'"' Ml llUIPP WIS.OSI 

351 IS.Gll 

=11:i~ 

=11=~~ WIKHAH 

.1:.i lli.H•D 41hH•E 

MlllLll.IF 

IGUIKIU'L 

:llil 111.llUH :ldll.HHI 

1'11Kllll 

HllKlllh. 

..aJlhlli.JI 

:llllKIUl"i 

ICllUl'\O 

......... ......... 

:rtll.H•T 

.IOI lli.BTL 

"i21.i.Hl\ 

J"l lllHUI' .TtlKH•X 

Jillllll:I.\ aa;11.au. 

~iilll&~ ,... ....... ...... , .. :1111 IKIGI In IKIHI WIKl.IJI 

:tllll&llL'\ 

:.N lli.l\P 11G IKIPT Jto11a1s..1 

3NllKll• 

Mlli.IU, 

300 

H.oot+ 

3'.Jllhlft\ 

:tll IKI)..\ l'l.lllt.,u: 

JIA IK,RF :ICll IK,Plo ....... ,..11 3'JG lhUI :tor 111.''"' :t.11111.,llh. 

:t'Jlllhll• 

........ ,,"Ii •H IK, .. 11 •o:llh.,'111" 

:.Mtj~; ... ~. IK,PI llld lh..llM\ tn"lh..lll" 

hlllhl\"\ 

411111 IK"'" Ulllh.11..H 

411 UL,YP 412 Ill.KA• 11:1 IKKUfl mlKli.Pll 

H~ lh.ILH UG lh.Kllh Uilhll.llJI 

Ull lh.Kllilo llS lh.11..110 .... llKIUllC ... :1111.h.5.T 

~l~~'l «!I IKh.H" t:lllLKTX 

t~ Ill.KL\ t7ilh.h.U. 

.f.:lllli.K'U" 

•t!llh.Kl.11 

............. 

GI IKJlllll 432 lh.JIDI 431 lh.Jl&I 

:111~=~~ ...,.lhJl5.l 

a· 111.11111\ t3S IK1U1X I 43911.Jll,l 

....... ,. HI IKJl11U Hllh.JUCH 

•"l:lllh.JIU' 

HllK!lio.lll 

-I.a ... ,.., 

HG lh.\lt.I Ui lh.\Fh. 

'"" lh."lifl\ Hllh."lillH 

f:iOllLMP 

.... 1 IK!li.llH &s:?llUlih.T 

fUIK!Ull 

fMlll.:!ili\ .. f~lh.511" 

..,, .. ,..,. ..... i lh\li\ "5.'o IK\ID 10 lh.5.\D """ .. , .. .. .. ........... \ .. ti"..! llL"li\C1 f11 lh.UU.ll 

4•-4 lh.Hlh .... , ....... , .....-111.uc.11 

... -111.1111.p ..,..., lhH'T 

Figure 7'7. 

IKB (Dou) 

" ICl!rllanslllnt.• '(II t1111ia1&1liWh•l"'l'lll'l•llh 

'~~•Ina 11 !1111111 u 1-1 

W1t11dri .. l111C(41 W11h r.. li'nontv lo Jn• lni:f"I 

,.,~~l1u1111lr.i.•lni:c•> 

llr:r.••11)' 

llr•wn1ri1 

llr.1•1111111 

classification, for even as late as in 1915 th.ere was no real or definite classification system for 

security purposes. The instructions recommended certain precautions. "The War Department Telegraph Code," says paragraph 5 of the instructions, "while not absolutely confidential, will be guarded with the greatest care and will never be out of the immediate possession 

or control of the officer to whom issued or of his confidential agent. Care will be taken to prevent theft, loss, use, or inspection except by those whose duties require them to employ the 

code. Special pains will be taken to prevent the code from falling into the hands of unauthorized 

persons or of the enemy." 

This new code was intended, as was its predecessor, to serve two purposes: "First, secrecy, 

and second, economy. 'When secrecy is desired it is to be used as a cipher code, as is explained 

in subsequent paragraphs under 'Enciphered Code.' " But there are no subsequent paragraphs 

in which this is explained. Apparently some change in this regard was decided, because I 

have seen, as a separate pamphlet, a set of cipher tables for use with this code. 

The code itself embodied some of the latest ideas of code compilation. It had over 113,000 

code groups, and these were both 5-:figure groups and, for the :first time, 5-letter groups. The 

latter embodied the principle of the 2-letter difference, but the instructions do not mention 

this fact and no permutation table was included in the code itself. The book has a very ext.ensive vocabulary of words, phrases, and sentences. Here is a picture of a typical page (Fig. 

77). I feel sure that a great deal of thought and effort went into the production of this code, 

but I must tell you two things about it. First, I must tell you that my immediate predecessor in 

the Office of the Chief Signal Officer told me, on my return from France in 1919, that that particular edition of the War Department Telegraph Code had been printed in Cleveland by a commercial printer, and second, that when the United States became a belligerent in World War I 

99 
REF ID:A63860 

our British Allies found it desirable to notify the U.S. Government (through our G-2) that 

our War Department Telegraph Code was not safe to use, even with its superencipherment tables. 

The implications of this notification are rather obvious and hardly require comment. The 

compilation of a new code in 1917 was initiated, but this time the work was done within and 

under the direction of the Military Intelligence Division of the General Staff (G-2), and in 

particular within the section devoted to cryptanalysis. This undertaking, which indubitably 

was a direct affront to the Signal Corps of the Army, met with no objection, it seems, from 

that group; perhaps it deserved the intended insult because of its longstanding neglect of its 

clear responsibilities for cryptography and cryptographic operations in and for the Army. 

We have noted how inadequately the Army and the War Department were equipped for 

cryptocommunications in the years from 1885 to 1915. Let us see how well equipped the 

Navy and the Navy Department were. For this purpose I have an excellent example and 

one of great historical significance and interest. You will recall my mention of the appointment of a board of Navy officers to prepare a suitable cryptosystem for the Navy and I told 

you about the large basic vocabulary and tabular contents of the codebook and its accompanying two large books, one for enciphering the code groups, the other for geographical names. 

For the story we go back to the time of President McKinley, whose election brought Theodore 

Roosevelt, a former member of the Civil Service Commission, back to Washington as Assistant 

Secretary of the Navy. Teddy was an ardent advocate of military and naval preparedness. 

He forthrightly and frankly favored a strong foreign policy, backed by adequate military and 

naval strength-"speak softly but carry a big stick" was his now famous motto. He was 

looking forward, in fact, to forcing the ultimate withdrawal of the European powers from the 

Western Hemisphere. With vigor, he set to work to make the Navy ready. When the Battleship Maine was blown up in Havana harbor, on 15 February 1898, Roosevelt sharpened 

his efforts. During a temporary absence of his chief, Navy Secretary John D. Long, he took 

it upon himself to initiate the preparations which he had in vain tried to persuade the Secretary 

to make. He ordered great quantities of coal and ammunition, directed the assembling of the 

- ·--- ~ 

• 

• 

.· 

. · ··~rdar th•· Squadrc,~1 exco1i: Urnvcr.oy tf' il·:>nB 

i, ... _ .. .., 

~eeit :t"ull :lt coal. 1~1 t.1:· •lV•.m~. or d.ocl .r~; •• Hl war 

1J•r~1 O.lp.rn11~; :\ un t. ~ 1 :~\.lH,.,. - i~•"• 

/ ~ O' 0-~ r·' ,..,,. rr 

Figure 78. 

100 
• 

• 

REF ID:A63860 

CONF IDENTfl\L 

Fleet, and stirred the arsenals and navy yards into activity. On a miserably cold Saturday 

afternoon, ten days after the Maine was blown up, and still in the absence of Secretary Long, 

Teddy sat down and wrote out a cablegram to go to Commodore George Dewey, at Hong 

Kong. Here it is, with his bold signature at the bottom: 

That is the now historic message which alerted Dewey and which resulted in our taking 

over, under U.S. protection in the war with Spain which was declared ten days later, the Philippine Islands. 

You will note :that the message bears on its face a security classification, but the classification, 

"Secret and Confidential," was crossed out. That must have been many years later, for those 

three words appear in the plain text of the deciphered and decoded cablegram. Here is a 

picture of the code cablegram with its strange and outlandish code words, as it was received in 

Hong Kong: 

ltH\ l•na 

-:-- -~- ~,, /f-f /( • 

-- e EUBtern Ext.eusiou Australasia I Tl!A Great Northern Telegraph 

China Telegrapll Company, Ld. ''om11any of Co}Jenhagen. 

). I .,. • 

..... ;( (' • .. 1 . ... h U' -;_" .. f 

Figure 79. 

And now I show you the deciphered and decoded text, which I was fortunate in being able 

to produce by courtesy of the Chief of the Naval Security Group, who permitted me to consult 

and use the necessary code books which I found were still in Navy Security archives. To 

101 
REF ID:A63860 

OONFIBHNCflAL 

THEODORE ROOSEVELT, ASST. SECRETARY OF THE NAVY, TO ADMIRAL DEWEY, HONG KUNG, 

26 FEBRUARY 1898 

l l 2 If. 5 6 

2 WASSERREIF PAUSATURA BADANADOS CENTENNIAL TITUBANDI LOSCHBANK 

3 99055 62399 11005 16820 900l/Jlil 523911l 

4 99a.556 239.911 11J05.168 2a9.11Jam a52.3911J 

5 

5 

1 

2 

3 

4 

5 

1 

2 

3 

4 

5 

SECRET AND 

CONFIDENTIAL 

KEEP FULL 

OF COAL 

ORDER THE 

SQUADRON 

IN THE 

EVENT OF 

EXCEPI' 

DECLARATION 

OF WAR 

THE 

MONOCACY 

SPAIN 

TO 

HONGKONG, 

CHINA 

l~ 15 16 17 18 

APPILANTI DEPUGNERE DEMIDEVIL MONOS II.ABO ATOCHARON TACHONASEN 

llJ7319 25545 249811J 56346 99599 87782 

19 

11J73.192 

THE SPANISH 

SQUADRON 

2111 

DOES NOT 

LEAVE 

g1 

ASIATIC 

COAST 

lf.611J.959 

AND 

THEN 

987.782 

OFFENSIVE 

OPERATION(S) 

LEGEMD: 1 - Group Number. 

2 - Cable Word. 

3 - Cable Word No. ALIENATO'l'E( b) CRENCHA SPARRWERKE If. - Code Number ln Code. 

04665 5 - Meaning. 1146.653 211J9.983 ... KEEP OLYMPIA 

IN PHILIPPINE UNTIL FURTHER 

ISLANDS ORDERS 

(a) Correction necessary: The "A" is to be 

omitted. 

(b) Correction necessary: Group was 

received as ALIENATTE. 

Figure 80. 

translate a message in the code then in use three steps are necessary. First, the cable words 

(the peciiliar, outlandish words in line 2-WASSERREIF, PAUSATURA, BADANADOS, etc.) are sought 

in the cipher book, and their accompanying cable-word numbers set down. WASSERREIF yields 

99055; PAUSATURA yields 62399, BADANADOS, 11005, etc. The next step is to append the 

first digit of the second cable-word number to the last digit of the :first cable-word number to 

make the latter a six-digit number. Thus 99055 becomes 990556. The six-digit code group 

number, 990556, is then sought in the basic code book and its meaning is found to be "Secret 

and Confidential." The transfer of the :first digit, 6, of the second cable-word number, 62399, 

makes it become code-number 2399, to which must now be appended the :first two digits of 

the third cable-word number, 11005, thus making the second code group of the code message 

239911, which is sought in the basic code book and yields the meaning "Order the squadron." 

And so on. It's painfully slow work, and I haven't told you about some of the difficulties I 

encountered in the process, including having to refer to the third book, the General Geographical 

Tables. It took me at least an hour to decipher and decode this one relatively short Roosevelt 

102 
REF ID:A63860 

C9NPIBENTIXL 

message. I feel sure a naval operation in World War II or in World War I, for that matter, 

could never have been executed before a message even as brief as the Roosevelt one could be 

deciphered and decoded by this cwnbersome system, even if all the digits had been transmitted 

and received correctly. Generally speaking, naval battles are fierce and quickly over. For 

instance, on 4 June 1942, between 10:24 and 10:26 a.m., the war with Japan was decided when 

the U.S. Pacific Fleet under Admirals Nimitz, Fletcher and Spruance won the Battle of Midway, 

in which the Japanese lost four fast carriers, together with their entire complement of planes, 

and almost all their first-string aviators. When our Navy entered World War I a much more 

practical system was put into effect, using a cipher device known as the NCB, standing for 

"Navy Cipher Box," to encipher 5-letter groups of a basic code. 

We come now to European events of importance in this cryptologic history. During the 

decades from the end of the Civil War in America to the first decade of the 20th Century, 

there was some progress in cryptologic science in Europe, but it was not of a startling nattire. 

German Army Major Kasiski's demonstration of a straight forward, mathematical method of 

solving the Vigenere cipher was published in Berlin during the mid-period of the Civil War in 

America. If the book created an impression in Europe, it was altogether unspectacular; in 

America it remained unheard of until after the advent of the 20th Century. Although Kasiski's 

method is explained quite accurately in the first American text on cryptology, 2 the name 

Kasiski doesn't even appear in it. Other books on cryptologic subjects appeared in Europe 

during this period, and two of them deserve special attention. The first, by Commandant 

Bazeries, is a book notable not for its general contents, which are presented in a rather disorganized, illogical sequence, but for its presentation of a cipher device invented by the author, the so-called "cylindrical cipher device." But our own Thomas Jefferson anticipated Ba7a'ies by a century, and the manuscript describing his "Wheel Cypher" is among the Jefferson 

Papers in the Library of Congress. The second book which deserves special attention is one 

by another French cryptologist, the Marquis de Viaris, in which he presents methods for 

solving cryptograms prepared by the Bazeries cipher cylinder, and although unknown to him, 

the ciphers of Jefferson's Wheel Cypher. 3 

It was in the period during which books of the foregoing nature were written and published 

that the chanceries of European Governments operated so-called "Black Chambers," organized 

for solving one another's secret communications. Intercept was unnecessary because the 

governments owned and operated the telegraph systems, and traffic could be obtained simply 

by making copies of messages arriving or departing from telegraph offices or passing in transit 

through them. This was true in the case of every country in Europe with one very important 

exception: Great Britain. The story, which is given in detail in a recently published and 

very fully documented book, 4 is highly interesting but I must condense it to a few sentences. 

In England, from about the year 1540 onward until 1844, there was a "black chamber" in 

constant operation. It was composed of three collaborating organizations within the Post 

Office respectively called "The Secret Office," the Private Office," and "The Deciphering 

Branch." 

In the first of these carefully hidden secret organizations, letters were opened, copies of 

them were made, the letters replaced, the envelopes resealed, and if the wax seals were intact 

they were merely replaced. If the seals were not replaceable, duplicates were forged and affixed to the envelopes. Copies of letters in cipher were sent to the "Deciphering Branch" 

2Capt. Parker Hitt's Manual for U&e Solution of Military Ciphers, Fort Leavenworth, Kansas: Army Service 

Schools Press, 1916. 

3L'art de chiff'rer et dkhiff'rer lea depAches secr~tes, Paris, 1893. 

"Ellis, Kenneth L. The Post Office in The EighteenU& Century: A Study in Administrative History. London: 

O:icf:>rd University Press, 1958, pp. 176. In conjunction with this book one should by all means also read the 

following extremely interesting and revealing article by the same author: "British Communications and 

Diplomacy in the Eighteenth Century," Bulletin of the Instituf.e of Historical Research, Vol. XXXI, No. 84, 

Nov 1958, pp. 159-167. 

103 
REF ID:A63860 

OONFIBHNBAL 

for solution and the results, if successful, were then sent to the Foreign Office. A famous 

mathematician, John Wallis, took part in the latter activities. The "Private Office" took 

care of similar activities but only in connection with internal or domestic communications. 

In 1844, a scandal involving these secret offices caused Parliament to close them down completely, so that from 1844 until 1914 there was no black chamber at all in Britain. As a consequence, when World War I broke out on the first of August 1914, England's black chamber 

had to start from scratch. But within a few months British brains and ingenuity built a 

cryptologic organization known as "Room 40 O.B.", which contributed very greatly to the 

Allied victory in 1918. Although the British Government has never issued a single official 

publication on the activities and accomplishments of "Room 40 O.B.," several books by private authors have pushed aside the curtain of secrecy to make a most fascinating story too 

long to tell in this lecture. But I must tell you at least something about what was perhaps the 

single greatest achievement of "Room 40 O.B.," an achievement which just in the nick of 

time brought this country into World War I as an active belligerent on the Allied side and 

saved England from possible destruction, as well as France. The operation involved the 

interception and solution of a message known as the Zimmermann Telegram, deservedly 

called the most important single cryptogram in all history. On 8 September 1958 I gave before 

an NSA audience a detailed account of this amazing cryptogram. I told about its interception 

and solution; I told how the solution was handed over to the United States; how it brought 

America into the war on the British side; and how all this was done without disclosing to the 

Germans that the plain text of the Zimmermann Telegram had been obtained by interception 

and solution by cryptanalysis, that is, by science and not by treason. My talk was given 

under the auspices of the NSA Crypto-Mathematics Institute, was recorded, and is on file 

so that, if you wish, you can hear it. It took two and a half hours to deliver and at that I 

didn't quite succeed in telling the whole story. But you may read an excellent account of 

this episode, set forth in great detail in a book entitled The Zimmermann Telegram, by Barbara 

Tuchman, published in 1958 by the Viking Press, New York. Also, you should consult a 

book entitled The Eyes of the Navy, by Admiral Sir William James, published in 1955 by Methuen 

& Co., London. Both books deal at length with The Zimmermann Telegram and tell how 

astutely Sir William Reginald Hall, Director of British Naval Intelligence in World War I, 

managed the affair so as to get the maximum possible advantage from the feat accomplished 

by "Room 40 O.B." It was, indeed, astounding! To summarize, as I must, this fascinating 

and true tale of a very important cryptanalytic conquest, let me show you again the telegram 

as it passed from Washington to Mexico City, for if you will remember, I showed it to you in 

the very first lecture of this series, and promised to tell you about it later. Here I show it 

to you once again. As you can easily see, the code groups are composed of three, four, and 

five-digit groups, mostly the latter. Here is the English decoded translation of the message 

as transmitted by our Ambassador Page in London to President Wilson: 

'Foreign Office Telegraphs Jan. 16, No. 1. Most secret. Decipher yourself. 

'We intend to begin unrestricted submarine warfare on the first of February. We shall endeavour in spite of this to keep the United States of America neutral. In the event of this not 

succeeding, we make Mexico a proposal of alliance on the following basis. Make war together, 

make peace together, generous financial support and an understanding on our part that Mexico 

is to reconquer the lost territory in Texas, New Mexico and Arizona. The settlement in detail 

is left to you. You will inform the President (of Mexico) of the above most secretly as soon as 

the outbreak of war with the United States of America is certain, and add the suggestion that he 

should, on his own initiative, invite Japan to immediate adherence, and at the same time mediate 

between Japan and ourselves. Please call the President's attention to the fact that the ruthless 

employment of our submarines now offers the prospect of compelling England, in a few months, 

to make peace. 

'ZIMMERMANN.' 

From the day that Ambassador Page sent his cablegram to President Wilson, on 28 February 

1917, quoting the English translation of the Zimmermann Telegram in the form in which it 

had been forwarded by German Ambassador von Bernstorff in Washington to German Minister 

104 
REF ID:A63860 

.............................. __ ..... .....,. ...... _...., .......... ~ 

GEllllAll LEGATION \? llEllCO CITY 

130 13042 13401 8501 115 3528 418 17214 8491 11:!110 

18147 18222 215eo 10247 11518 23877 1s805 S.9' 141138 

"8C92 59C5 11311 1C392 10371 0302 21290 5181 :!19895 

~35'71 17504 112"9 1827e 18101 0317 0228 1789o& "7S 

~E2e4 22200 1945:2 21589 87893 5589 1918 8958 12137 

13~3 4725 H5e 59C5 17188 13851 4458 17149 14o&71 8708 

!385l 12224 8929 14991 7382 15857 e7893 14218 SM77 

I E"1C' 1 .. ~:;.~ .... en? 5e7C M54 1e102 15217 22801 171:!18 

.1 ices ,, .. 3l1e '711e 23e3e 182U P'l19 11331 15021 11845 

:S1 ,, ~~~52 22<'9~ 21!!04 4797 049~ 224flC 2085& 4:117? 

23t"•( 18140 222PC 5905 13347 20420 :59889 1:117:112 8011117 

C~2' 5.:?~5 18s:· 522fl:: 13CC 22049 13339 11285 22295 

!C43!1 14814 4178 e992 8784 7e32 7357 8128 52111111 111!8'1 

211CO 21272 934' 9559 224'' 15874 18502 18li00 11111'1 

218d 53':8 'i381 98092 Je127 1:11'88 9350 9220 7llOlll 1C111 

5144 2831 17920 11347 17142 11284 7887 77811 SIDll ltlll 

10'82 97558 3589 387C 

BEPllSTOPFF. 

Figure 81. 

von Eckhardt in Mexico City, the entrance of the United States into the war as a belligerent 

on the side of the Allies became a certainty. Under big black headlines the English text appeared in our newspapers, because, after assuring himself of the authenticity of the telegram 

handed over by the British and that it had been decoded and checked by a member of Ambassador Page's own staff, President Wilson directed that the text of the message be released 

to the Associated Press. Its publication the next day was the :first of a momentous and sensational series of reports and accounts of the Zimmermann Telegram and its contents. 

There were plenty of members of Congress who disbelieved the story. But when Zimmermann himself foolishly acknowledged that he had indeed sent such a telegram, disbelief 

changed quickly into most vehement anger. Thus, it came about that Americans in the 

Middle West and Far West, who had thus far been quite unconcerned about a War that was 

going on in Europe, thousands of miles away, and wanted no part of it, suddenly awoke when 

they learned that a foreign power was making a deal to tum over some rather large slices of 

U.S. real estate to a then hostile neighbor across the southern border. They were aroused to 

the point where they, too, as well as millions of other Americans in the East, were ready to 

fight. Surely war would now be declared on Germany. 

Notwithstanding all the furor that the disclosure of the Zimmermann Telegram created in 

America, President Wilson still hesitated. He was still determined that America would not, 

must not, fight. It was not until more than a month later, and aff;er several American ships 

were sunk without warning on 18 March, that a now fully aroused President got Congress to 

declare war on Germany and her allies. The date was 6 April 1917. 

In the War Department and in the Navy Department the pace set for preparing for active 

war operations quickened. It is difficult to believe, but I assure you that it was true, that 

105 OONFIBE!fflAL 
REF ID:A63860 

CON'PI:BEN't'IAL 

there was at the moment in neither of those departments, nor in the Anny or Navy, any organizations or technical groups whatever, either for intercepting enemy communications or 

for studying them, let alone solving such communications. There was, it is true, since the 

autumn of 1916, a very small group of self-trained cryptanalysts, sponsored and supported 

by a private citizen named Colonel George Fabyan, 6 who operated the Riverbank Laboratories 

at Geneva, Illinois. I served as leader of the group, in addition to other duties as a geneticist 

of the Laboratories. Riverbank, through Colonel Fabyan, had initiated and established an 

unofficial or, at most, a quasi-official relationship with the authorities in Washington, so that 

it received from time to time copies of cryptographic messages obtained by various and entirely 

surreptitious means from telegraph and cable offices in Washington and elsewhere in the U.S. 

At that period in our history diplomatic relations with Mexico were in a sad state, so that U.S. 

attention was directed southward, and not eastward across the Atlantic Ocean. Therefore, 

practically all the messages sent to Riverbank for solution were those of the Mexican Government. Riverbank was successful in solving all or nearly all the Mexican cryptograms it was 

given, usually returning the solutions to Washington very promptly. The great majority of 

them were of the Vigenere type but using mixed sequences with relatively long key phrases. 

Riverbank was also successful with certain other cryptograms which were concerned with the 

war in Europe, but I cannot deal with them now because there just isn't time. Soon after the 

U.S. declared war on Germany, Colonel Fabyan established a school for training at Riverbank, 

and he invited the Services to send him Army and Navy officers to learn something about 

cryptology in formal courses established for the purpose. Each course lasted about six weeks, 

full time. 

You may like to know what we novices used for training ourselves for this unusual task 

and what we used later on for training the student officers sent to us for cryptologic instruction. 

As regards our self-instruction training material, there wasn't much available in English, but 

among the very sparse literature there was that small book by Captain Parker Hitt, called 

Manual for the Solution of Military Ciphers, to which I referred earlier. Colonel Fabyan 

managed to get a copy of that Manual, for us to study. The Signal Corps School was then 

one of the Army Service Schools, and there a few lectures were given by two or three officers 

who, when World War I broke out in August 1914, took an interest in the subject of military 

cryptography. They foresaw that sooner or later there would be a need for knowledge in that 

important branch of military technology. Capt. Hitt's Manual was then, and still is, a model 

of compactness and practicality. Let me show you the title page of the :first edition (Fig. 82). 

It was the succinctness of Parker Hitt's Manual that caused us much work and perspiration 

in our self-training at Riverbank, but we later came to know and admire its author, whose 

photograph I now show you as he looked when he became a Colonel in the Signal Corps (Fig. 83). 

There was one other item of training literature which we also studied avidly. It was a very 

small pamphlet entitled An Advanced Probl,em in Cryptography and its Solution, and it too was 

put out by the Fort Leavenworth Press in 1914. Here is its title page (Fig. 84). You will 

note that its author was then 1st Lieut. J. 0. Mauborgne; he advanced to become a Major 

General and Chief Signal Officer of the Army (Fig. 85). The "advanced problem" dealt with 

in that pamphlet was the Playfair Cipher, about which I shall say only that at the time Mauborgne wrote about that particular cipher it was considered to be much more difficult than it 

is at present. 

Returning now to what Riverbank's self-trained cryptanalytic group was able to do in a 

practical way in the training of others, there exist in NSA archives copies of the many exercises 

and problems prepared at Riverbank for this purpose. They are, I think, still of much interest 

as curiosities of U.S. cryptologic history. 

In Lecture II, I showed you a picture of the last of the several classes sent by the Anny to 

Riverbank for training. It should be noted, and it gives me considerable pleasure to tell you, 

&Honorary title conferred by the Governor of Illinois for Fabyan's participation as a member of the Peace 

Commission that negotiated the Treaty of Portsmouth, which terminated the Russo-Japanese War in 1905. 

106 
.. 

REF ID:A63860 

MANUAL 

FOR THE SOLUTION OF 

MILITARY CIPHERS 

•• PARKER HITT 

C•Jl11.1• •/ l•/••tr,, U S f 

PREIS OF 

THE ARMY !IEl.\'ICE. ILllOOLS 

Fall LrHrm•anh lb.nut 

191 6 

Figure 82. 

AN ADVANCED PROBLEM 

IN CRYPTOGRAPHY AND 

ITS SOLUTION 

.. 1>1 llH'1•''1.'I J 0 MAllRURU, •• , 

.11h ".,,r., 

l"&tb CH 

I IU. ARM\ S•.R\'ll'h SClllKll.S 

1914 

Figure 84. 

107 

Figure 83. 

Figure 85. 
REF ID:A63860 

CONPIBEN'A.\I. 

that this instruction was conducted at Colonel Fabyan's own expense as his patriotic contribution to the U.S. war effort. I can't, in this lecture, say much more about this than that it 

involved the expenditure of many thousands of dollars, never repaid by the government-not 

even by income-tax deduction or by some decoration or similar sort of recognition. Upon 

completion of the last training course, I was commissioned a First Lieutenant in Military Intelligence, General Staff, and ordered immediately to proceed to American General Headquarters in France, where I became a member of a group officially referred to as the Radio 

Intelligence Section. But it was the German Code and Cipher Solving Section of the General 

Staff, a designation that was abbreviated as G-2, A-6, GHQ-AEF. As the expanded designation implies, the operations were conducted in two principal sections, one devoted to working on German Army field ciphers, the other, to working on German Army field codes. There 

were also very small groups working on other material such as meteorologic messages, directionfinding bearings, and what we now call traffic analysis, that is, the detailed study of "the externals" of enemy messages in order to determine enemy order of battle and other vital intelligence from the study of D/F bearings, the direction, ebb and :flow of enemy traffic, and 

other data sent back from our intercept and radio direction-finding operations at or near the 

front line in the combat zone. 

In connection with the last-mentioned operations you will no doubt be interested to see what 

is probably one of the earliest, if not the very first, chart in cryptologic history that shows the 

intelligence that could be derived from a consideration of the results of traffic analysis. Its 

utility in deriving intelligence about enemy intentions from a mere study of the ebb and :flow 

of enemy traffic, without being able to solve the traffic, was of unquestionable value. Here's 

that historic chart (Fig. 86), which I must tell you was drawn up from data based solely upon 

the ebb and :flow of traffic in what we called the ADFGVX cipher, 6 a clever cryptosystem which 

was devised by German cryptographers and which was restricted in its usage to German High 

Command communications, principally those between and among the headquarters of divisions and army corps. I ts restriction to such high command messages made a study of its 

ebb and :flow very important. Theoretically, that cipher was extremely secure. It combined 

both a good substitution and an excellent transposition principle in one system without being 

too complicated for cipher clerks. Below is a diagram which will give a clear understanding of 

its method of usage. If you wish further details I suggest you consult documents available in 

the Cryptanalytic Literature Staff of the NSA O:ffi.ce of Training Services. In this lecture 

there is only time to tell you that although individual or isolated messages in the ADFGVX 

system then appeared to be absolutely impregnable against solution, a great many messages 

transmitted in it were read by the Allies. You may be astonished by the foregoing statement 

and therefore may desire some enlightenment here and now on this point. In brief, there 

were in those days three and only three different methods of attacking that cipher. Under 

the first method it was necessary to find, as the first step, two or more messages with identical 

plaintext beginnings because they could be used to uncover the transposition, which was 

the second step. Once this had been done, the cryptanalyst had then to deal with a substitution cipher in which two-letter combinations of the letters A, D, F, G, V, and X represented 

single plaint.ext letters. The messages were usually of sufficient length for this purpose. Under 

the second method, two or more messages with identical plaint.ext endings could be used to uncover the transposition. This was easier even than in the case of messages with identical 

beginnings. You might think that cases of messages with identical beginnings or endings 

would be rather rare, but the addiction to stereotypic phraseology was so prevalent in all 

German military communications that there were almost invariably found, in each day's 

traffic, messages with similar beginnings or endings, and sometimes both. Under the third 

method of solution it was necessary to find several messages with exactly the same number of 

letters. This happened, but not often. This system first came into use on 1 March 1918, 

a Initially this cipher employed only the letters A, D, F, G, and X, for a matrix of 5 X 5; later, the letter 

V was added, for a matrix of 6 X 6, for the 26 letters of the alphabet plus the ten digits. 

108 
....-...... - ............. ~ -- -..::..- ;;. 

jl----+--+--+--1-

1!! 

~ 

REF ID:A63860 

1- - -t---- - -

--I--+--+- ·--

1--~'~·~·-+--+-----1f---+--I----+---~-- -

11 • lii1 

a1------1-+·-"-1--+--.....,~· - . !. -+--+- --i---- ~- -· - -1---+--1- ~t---+--+----+--.~. --+----< 

'· · 1: ··r· ""'t---:--1·--1---+---+---t-- ;---+---~ ---+--!----+-·--+-- 1---t---+----1-.,.,.-t--t---i = ,t:i:h ~ .. r - --:: rj_: ·F I I' 

ii ' • . :;fy """' 'I.Ill Oft NllVI! 

.. . . I----+-- +--1----4- -. .::, .. _,. I 

: :::-~;:~ f :!J· .. 

~~- :~:- ;:y~- - - . ::::~~-I :t ~ •> I 1 I\' I t! _ . \r I\, 1• 

). '' I I I '"I 

- .1L.ailt! \ 1 Ill I I lh • 1•1 

-_. : ; I t..........in.m: ..... -~- ---~- \ / ~ /, .. --

1 : - i-----t-i-r,-'.'t----t-+----17'~-+--+-----lr---+-·--r----

;• I \ i .. ----= 1 'v' \ l1 ---- _ 

: \ \ ' I \ .~ <IMS 

~: ·-· -1:. 

I "'I. 

[ 

I " I 

'l'TS 

d 

~~ 

"'· 

1

1 .... ·.: ~ I I 1:~ ... c. L.Gc.\I. :, ,\ ,'1 4 •, .l 

I 

I . : r! ,. I 

~ ; ["' I I 

1':' ·ii: 

·'·- ,,. I: I·~ 

I \tl;:~ ', ~·~\, ·-al N~"a;-t -r -1--- .~- -- -•t-l', :L~'---• "l\'JL I --

;·;• \t ~-~: ~.. j J.: ,; ..... I ~· .. :"JI . ·.~\,: ;; \.~ ':·,It I J ~ • : .. 'i 1 •• I .. ~ ~ .. ~~ \ ~ 1o-"' -.. --. f u, '

1 

l~,L-.- •• 

1..... 1 .. 1.y "'- ~ 

Figure 86. 

three weeks before the last and greatest offensive by the German Army. Its appearance was 

coincident with that of other new codes and ciphers. The number of messages in the ADFGVX cipher varied from about 25 a day, when the system :first went into use, to as many as 

about 150 a day at the end of two months. It took about a month to :figure out a method 

of solution, and this was :first done by a very able cryptanalyst named Capt. Georges Painvin 

of the French Army's Cipher Bureau. 

The ADFGVX cipher was used quite extensively on the Western Front with daily changing 

keys during May and June of 1918, but then, for reasons somewhat obscure, the number of 

messages dropped very considerably. How many different keys were solved by the Allies 

during the four months from 1 March to the end of June? Not many-10 in all; that is, the 

keys for only 10 different days were solved. Yet, because the traffic on those days was very 

heavy, about 50% of all messages ever sent in that cipher, from its inception to its discard, 

were read, and a great deal of valuable intelligence was derived from them. On one occasion 

solution was so rapid that an important German operation disclosed by one message was completely frustrated. 

Although the ADFGVX cipher came into use :first on the Western Front, it later began to 

be employed also on the Eastern Front, with keys that were :first changed every two days but 

109 CONPIBBN'f'l2\:L 
REF ID:A63860 

Plain text: REQUEST REENFORCEMENTS IMMEDIATELY 

Second letter 

A D F G v x 

A Q u E 5 s T 

D I 9 0 N A l 

Enciphering First F B 2 L y c 3 

Square: letter 

G D 4 F 6 G 7 

v H 8 J 9J K M 

x p R v w x z 

.... 

.... Biliteral Substitution: R E Q u E s T R E E N F 0 R c E 0 

XD AF AA AD AF AV AX XD AF AF DG GF DF XD FV AF 

M E N T s I M M E D I A T E L y 

vx AF DG AX AV DA vx vx AF GA DA DV AX AF FF FG 

Key Word: Q u I c K B R 0 w N F 0 x J u M p E D 

14 16 6 2 8 l 15 11 18 10 5 12 19 7 17 9 13 4 3 

y D A F A A A D A F A v A x x D A F A 

Substituted F D G G F D F x D F v A F v x A F D G 

Text: 

A x A v D A v x v x A F G A D A D v A 

x A F F F F GI 

Transposed Text: ADAFF GVFAG AFDVA VAAGA FXVAA FD FDA AFFXD XXVAF AFDXF AXAFV GDDXA 

XXDAD VAFG 

e 
REF ID:A63860 

later every three days. On 2 November 1918 the key for that and the next day was solved 

within a period of an hour-and-a-half because two messages with identical endings were found. 

A 13-part message in that key gave the complete plan of the German retreat from Roumania. 

During the 8 months of the life of the ADFGVX cipher, solution depended upon the three 

rather special cases I mentioned. No general solution for it was thought up by the Allies 

despite a great deal of study. However, members of our own Signal Intelligence Service, in 

1933, devised a general solution and proved its efficacy. Pride in this achievement was not 

diminished when, in the course of writing up and describing the method, I happened to find a 

similar one in a book by French General Givierge (Cours de Cryptographie, published in 1925). 

Givierge was by then the head of the French Black Chamber which was called the "Deuxieme 

Bureau," corresponding to our "G-2." 

TADLS--1-THE ALPHABETS POB THE "WILHELM" CIPllER 

ABCDEFGHIJKLMNOPQRSTUVWXYZ 

A SQRYVXUZTWBDCAEJHKIFGPMONL 

B LOPNMQSRTUVZXYWCABHEDGJFKI 

C PONMRTSQWYUXZVCABEDFJGKHIL 

D IFHJGNKLMPOTSRQVYUXZWDBCAE 

E XUVZYWACBEDGIHJFKMONLTRSQP 

F UXZWYVAEBCFDIHGJNKMLSPORTQ 

G ACDBHJFIGEMNLKOTRSTQYZVUXW 

H BADCFGEIHJNOKMLSRPTQWXVYUZ 

I TRSQYWXZVUEBACDKFJIGHMLPNO 

J LMONTQRPSZXUYVWBACDEGJHFKI 

K MOKNLQSRPWZTVUXYDBACEFJGIH 

L IEHFGLOMJKHQPTRSXVYUZVBADC 

M HFIGNMJKOLQPSRVTZUWXYBEDCA 

N CDABGHEJFIKMPOLNTRQSXUZWVY 

0 ECDBAFJIGHLKONMSPQTRZUXVWY 

P RQPSZWTVUXYDBCAGIEJHKFONLM 

Q VYXUZWCABEDIHGFLKNMJQOTPSR 

R BACHDJFEGILONPKMSQRUZTYYWX 

S QYZVXABCEFDMJIGKAPLNSROYUT 

T EDIGHFLMKPONRQJSUXTZWYYCAB 

U RTSWVYZUXFACBEDJKIGHONMPQL 

V MOLNPSRQXTYWZUVADCBHFIKEJG 

Numbers were expressed by the following lettcra bracketed between "Q'•"· 

1234567890 

HPJWDYVRAF 

Tho alphabet beginning "SQRYV" wu known u the "A.'' alphabet, thetbeginning "LOPllll" 

as tho "B" alphabet, etc Messages numbered 1, 31, 61, etc, were dOClpborablo by the 18 alphabets in the order 

"JVCEPQHCMPQGP". 

Messages numbered 2, 82, 62, ale , wore dempharable by the 18 alpliabets in tho ordor 

''TBUULENFKEQGC'' 

Tho horizontal sequeDco above the &able 10 the plain-tezt sequeDce The vertical alphabet 

on the utreme Ief& gives the arb.t&razy aymbol b;y .. Juch the difrorent alphabets were known 

n the 30 keya. .Attached is 11 hat of theo1 IO kep· 

Figure 87. 

The ADFGVX cipher was not the only one used by the Germ.an Army in World War I, 

but there will be time to mention very briefly only two others. The :first of these was a polyalphabetic substitution cipher called the "Wilhelm," which used a cipher square with disarranged alphabets and with a set of 30 fairly lengthy key words. The cipher square is shown 

in Fig. 87. Just why the square contains only 22 rows instead of 26 is probably connected 

with the fact that German can get along very well with fewer than 26 letters. Certainly the 

rows within the square are not random sequences, as you can see, for the letters within them 

manifest permuted arrangements in sets of :five letters. In Fig. 88 is shown the keys used-30 

of them. The key sequences seem to be composed of random letters but underlying them is 

plain text. I leave it to you to try to reconstruct the real square, if possible. You should be 

able to reconstruct the real keys, for the latter problem should be relatively easy. 

111 
REF ID:A63860 

1---- J V C E P Q H C M P P G P 

2 ____ T B U U L Et N F K E Q G J 

3 ____ V C B H E G C J K G E P 

""---- I 0 C E B P G K K G P J V E G U G C 5 ____ H G J K E I I M P Q J B C K 

6---- S 0 F C K M P K G C H C G N F M P Q 

7 ____ L 0 Q G P L G N F J G U 

s ____ L B U U G P J E G S 0 F C G P 

9---- P B N F G K L 0 J I E U N F 

10 ____ G J J N F I G N A K I E C 

11 ____ A B C A D E G F G C 

12 ____ D M N A G C D 0 P Q G 

13---- J N F L E G Q G C T 0 K G C 

14 ____ L E G U 0 P Q G R 0 ll G C K G J 

15 ____ L E G T E G U A B J K G K G J 

16 ____ S C G I R G P H M N F 

17---- H G P G R E A K E P G C 

18---- J G U K G C L 0 J J G C 

10 ____ H G E L G I A 0 M S G P J E G 

20 ____ V 0 V E G C F 0 P R U ll P Q 

2L ___ V S G C R G T G C I E G K G C 

22 ____ Q B U R 0 C H G E K G C 

23 ____ F 0 P R U M P Q J Q G F E U S G 

24 ____ F 0 P R J N F M F I 0 N F G C 

2,; ____ E P J K C M I G P K G P I 0 N F G C 

26 ____ A 0 I G U K C G E H G C 

27 ____ C 0 R E G C QM I I E 

28---- H G J B C Q G R E G V S G C R G 29 ____ R M P A G U A 0 I I G C 

30 ____ C G N F K J 0 G U G F C K G C 

It will be noticed that the samo letter, as P, for instance, m key no. 1, 1s repeated four 

chffcrent times Agnm, the E and Q and G \\lueh oceur 1n 1 occur also m 2 Tbeso facts 

pointed to the use m theso 30 kc)s or mtcllig1blo German \\Ords Tho arbitrary !otters, "hieh 

the keys m their present form contlWled, ...,presented a S1m11le substitution This appeared 

from tbe frequency, for cxumple1 of G and the inseparablo combmallons NF and NA, N nevur 

appcanng unless rollo"ed by For A It was therefore e."<trcmely probable that theso letters, 

arh1tranly chosen to represent tho 22 cWicrcnt al1>habcts, 1n reahty represented keywords 1n Gcrmnn toxt 

N was assumed to be tile ulue or C, and F, H, and G, the n1ost frequent letter wbieh was 

never absent from any or the senes, E. Tins sun pie subst1tub.on "as continued unW fam1bar German syllabics began to appear and finally tbe complete koy\\ords t.l1emselves. 

Figure 88. 

The other German Army cipher to be mentioned is the double transposition, an example of 

which is shown below. The process consists in applying the same transposition key twice to 

the same matrix, once horizontally and once vertically, as seen in this slide. Solution of the 

true double transposition usually depends upon finding two or more messages of identical 

length. (You will remember what I told you about Capt. Holden in this connection.) No 

general solution was known to the Allies during World War I, and messages of identical length 

were few indeed. But it happened that occasionally a German operator would apply only the 

Literal key: 

Derived numerical key: 

First transposition 

BUREAU 

2 5 4 :s 1 6 

ATTACK 

P 0 S T P 0 

NEDUNT 

ILFOUR 

AM 

Second transposition 

2 5 4 :s 1 6 

CPNUAP 

NIAATU 

OTSDFT 

0 E L II K 0 

TR 

Final cryptogram 

ATFKC NOOTU ADMNA SLPIT 

ERPUT 0 

:first transposition, and when this fortunate situation occurred solution was easy, because the 

key thus recovered from the single transposition could be used to decipher other messages 

which had been correctly enciphered by the double transposition. Again, the Signal Intelligence Service devised a general solution for the double transposition cipher, and during World 

War II we were able to prove that such ciphers could be solved without having to find two 

messages of identical length. I think the devising of a general solution for the true double 

transposition cipher represents a real landmark of progress in cryptanalysis. 

112 
REF ID:A63860 

OONPIBBN':l?IAfJ 

We come now to the code systems used by the belligerents in World War I. And first, let 

us differentiate those used for diplomatic communications from those used for military communications. What sorts did the German Foreign Office use? We have noted that the 

British Black Chamber, "Room 40 O.B.," enjoyed astonishing success with the code used for 

the transmission of the Zimmermann Telegram. Excessive pride in German achievements in 

science, a wholly unjustified confidence in their communication cryptosecurity, and a disdain for the prowess of enemy cryptanalysts laid German diplomatic communications open to 

solution by the Allies to the point where there came a time when nothing the German Foreign 

Office was telling its representatives abroad by telegraph, cable or radio remained secret from 

their cryptologic antagonists. For those of you who would like to learn some details, I refer 

you to the following monograph on the subject by my late colleague, Captain Charles J. Mendelsohn: Studies in German Diplomatic Codes Employed During the World War, Government 

Printing Office, 1937. Copies of it are available in the Office of Training Services. Says Dr. 

Mendelsohn: 

"At the time of America's entrance into the war German Codes were an unexplored :field in 

the United States. About a year later we received from the British a copy of a partial reconstruction of the German Code 13040 (about half of the vocabulary of 19,200 words and 800 of 

the possibly 7,600 proper names). This code and its variations of encipherment had been in use 

between the German Foreign Office and the German Embassy in Washington up to the time of 

the rupture in relations, and our files contained a considerable number of messages, some of 

them of historical interest, which were now read with the aid of the code book." 

The vocabulary of the German diplomatic codes comprised about 189, pages each having 100 words or expressions to the page, arranged in two columns of 50 each, accompanied by numbers from 00 to 99. In each column the groups were in blocks of 10. In 

the left-hand column, for instance, were the five blocks from 00---09, 10-19, etc., to 40--49. 

Then 50-59, 60-69, etc., were jn blocks of 10 in the right-hand column. The pages in the 

basic code were numbered, and from this code several codes were made by the use of conversion 

tables. This enabled the original or basic code to serve as the framework for apparently unrelated and externally distinguishable codes for several different communication nets. What 

the number of the basic code was is unknown, but we do know that from the code designated 

as Code 13040 came codes 5950, 26040, and others, derived merely by means of tables for 

converting the page numbers in the basic code into different page numbers in the derived code. 

These conversions were systematic, in blocks of fours. Thus, for example, pages 15-18 in 

code 13040 became pages 65--68 in code 5950, etc. Then there were tables for converting line 

numbers from one code into different line numbers in another version of the basic code, and 

this was done in blocks of 10. For example, the fifth block (penultimate figure 4) became the 

first (penultimate figure 0), and the 1st, 2d, 3d, and 4th blocks were moved down one place. 

The other five blocks (on the right-hand side of the page) were rearranged in the same manner. 

It is obvious that codes derived in such a manner from a basic code by renumbering pager 

and shifting about the contents of pages in blocks can by no means be considered as being dif 

ferent and entirely unrelated codes, and once a relationship between two such codes was discovered, the two could be handled as equivalents of one another. Also to be mentioned is the 

fact that in certain cases numbers were added to or subtracted from the code numbers of a 

message, and this gave rise to what seemed to be still different codes. It was not difficult to 

determine the additive or subtractive and thus get to the basic code numbers. 

In none of the cases of codes mentioned thus far was there one that could be considered to 

be a randomized, "hatted," or true two-part code, since the same bookservedforbothencoding 

and decoding. However, the German Foreign Office later on did compile and use real twopart, truly randomized codes of 10,000 groups numbered from 0000 to 9999. One such code 

had as its indicator the number 7500. And that there were several others like it I have no 

doubt. 

When one reviews Dr. Mendelsohn's monograph, one becomes overwhelmed by the multiplicity of the codes and variants threof used by the German Foreign Office. Some were basic 

113 
REF ID:A63860 

codes, but many were derivatives or superencipherments thereof. It is even hard to ascertain 

the exact number of different codes and superencipherment methods. Yet a great deal of the 

traffic in these codes was read. Considering the rather small number of persons on the cryptanalytic staff of G-2 in Washington and in the British counterpart organization in London, 

the British Black Chamber, one can only be astonished by the remarkably great achievements 

of lhe1:1e two collaborating organizations that worked on German diplomatic codes during 

World War I. 

So much for German diplomatic secret communications. What about German military 

cryptocommunications? I have already mentioned several of the systems used, but these 

were developed two or more years after the outbreak of World War I. When World War I 

commenced, the German Army was very poorly prepared to meet the requirements for secure 

communications. It seems that up until the Battle of the Marne in 1914 several Army radio 

stations went into the field without any provision having been made, or even foreseen, for the 

need for speedy and secure cryptocommunications. Numerous complaints were registered by 

German commanders concerning extensive loss of time occasioned by the far too complicated 

methods officially authorized for use and the consequent necessity for sending messages in the 

clear. Not only did this reveal intelligence of importance to their opponents, but, what is 

equally important, the practice permitt.ed the British and the French to become thoroughly 

familiar with the German telegraphic procedures, methods of expression, terminology and 

style, and the knowledge gained about these items became of great importance in cryptanalysis 

when German cryptosystems improved. The German Army learned by hard experience 

something about its shortcomings in this area of warfare and not only soon began to improve 

but it did so to the point where we must credit the Germans with being the initiators of new 

and important developments in field military cryptography. In fact, the developments and 

improvements began not long after the Battle of the Marne and continued steadily until the 

end of the war. When on 11November1918 the armistice ended active operations, German 

military cryptography had attained a remarkably high state of efficiency. The astonishing 

fact, however, is that, although very proficient in cryptographic inventions, they were apparently quite deficient in the science and practice of cryptanalysis. In all the years since 

the end of World War I no books or articles telling of German success with Allied radio traffic 

during that war have appeared; one Austrian cryptanalyst, a man named Figl, attempted to 

publish a book on cryptanalysis, but it seems to have been suppressed. One could, of course, 

assume that they kept their successes very well hidden, but the German archives taken at the 

end of World War II contained nothing significant in regard to cryptanalysis during World 

War I, although a great deal of important information in this field during World War II was 

found. A detailed account of the cryptologic war between the Allied and German forces in 

World War II would require scores of volumes, but there is one source of information which 

I can highly recommend to those of you who would like to know more details of the cryptologic warfare between the belligerents in World War I. That source is a book written and 

published in Stockholm in 1931 by a Swedish cryptanalyst, Yves Gylden, under the title 

Chi/ferbyr&rnas lnsatser I Varldskriget Till Lands, a translation of which, with some comments of my own in the form of footnotes, you will find on file in the Office of Training Services under the title The Contribution of the Crypwgraphic Bureaus in the World War, Government Printing Office, 1936. 

In this lecture, however, we are principally concerned with German military cryptography 

during World War I, and since I have already told you something about the cipher systems 

that were used, there remain to be discussed the field codes. It was the German Army which 

first proved that the old idea that codebooks were impractical for use in the combat zone for 

tactical communications was wrong. They had two types of field codes: one which they 

called the SCHLUESSELHEFT but which we called the "three-nwnber code," the other 

which they called the SATZBUCH but which we called the "three-letter code". The former 

was a small, standardized code with a vocabulary of exactly 1,000 frequently used words and 

expressions, digits, letters and syllables, etc., for which the code equivalents were 3-digit nwn114 
,. 

• 

REF ID:A63860 

CONFt'.DEN I'IXL 

hers. A cipher was app1ied only to the first two digits of the code nwnbers and this cipher 

consisted of 2-digit groups taken from a 10 x 10 matrix for enciphering the nwnbers from 00 

to 99. This table was called the GEHEIMKLAPPE or "Secret Key," and here's a picture of 

one (Fig. 89). The last digit of a code group remained unenciphered. Thus, code group 

479 would become 629. Each division compiled and issued its own secret key table, which was 

in two parts, or sections, of course, one for encipherment, the other for decipherment. The 

three-number code was intended for use in all forms of communication within, or to and from, 

a 3-kilometer front-line danger zone. Although this code was completed by the end of January 1918, it was not distributed or put into use until the opening day of the last and greatest 

German offensive, 10 March 1918. Our code-solving section, through good fortune and careful attention, ascertained the nature of the new code, and a few groups in it were solved the 

very same day the code was put into effect, because a German cipher operator who was unable 

to translate a message in the new code requested and received a repetition in another code 

Yerschltlsselungsla/e/. En/sc/Jlii sselung.s/a/e/. 

0 I .2 J 

"" s (j 7 8 .9 () f 2 J ,,.. .J" ti 7 I .9 

, tf7 12 10 50 !73 l(JJ H .9.9 I~ ,(j 

I -M 2{) .91 8¥i°76fil (j.f .97 JJ "'' 2 /0 1¥ 2tf 00-lJ-2 I 71 t!O "'" ~ 08 

7.J"j_~ - J .JS" .f",(< .JO 12 9J 77 7.9 J2 ~ 

.,.. /7 2.S 29 1,1-2 "" 14() 9.f" 2¥ ()/' 21 

S' .f"f 37 i)!} (jJ 

~=ti" 9-S" .f"!J 06 ,,, ·- 6 IJ2 HJ '9-7 18 07 .J!J 48 49 6-9 2J -

0 23 u {j() ().; 78 .JS' S8 61- y .F2 

t 20 77 JJ S9 21 1'() 02 '1-0 6.J (J8 

2 ft' l'.9 fN 6'9 "'1-7 H ?.9 74'- 22 ~2 

J 32. 76 311 14 75 JO (J!J Sf 8() 65" 

• 61 19 Af If 06 .f(j 7.J ,62 f() 21 --.__ 

.f 8.F so 2¥ 18 Jf 8¥ 27 9() S'S' .F7 - - 5 OJ 91 96 SJ til 16 H 19 I'S 87 - 7 .97 25 71 ()¥ 9S' J~ 1¥ .37 9J .38 7 IS' 72 81 ~ 27 .3'1- JI fl (1¥ 26 

I J8 +J .95 115 5"S .!"O !}0 (jg .f".J 67 --- __ ,_ 

8 .to 7.Z Y+ 92 1.1 8J +.S' ()() 6'6' 6'7 

.9 46 '2191 J6 11.9 1<6 82 17 .9#- 07 , 57 61 83 78 98 7~ 62 7(} 92 !)¥ 

Figure 89. 

which had been solved to an extent which made it possible to identify homologous code groups 

in both messages. The three-number code proved rather easy to solve on a daily basis because 

only the encipher-decipher table was changed. Much useful intelligence was obtained from 

the daily solution of this key. 

The solution of the SATZBUCH, or three-letter code, however, proved to be a much more 

difficult problem. In the first place, it had a much larger vocabulary, with nulls and many 

variants for frequently used words, letters; syllables and numbers; in the second place, and what 

constituted the real stumbling block to solution, was the fact that it was a true two-part randomized or "hatted" code; and in the third place, each sector of the front used a different edition 

of the code, so that traffic not only had to be identified as to the sector to which it belonged but 

also it was not possible to combine all the messages for the purpose of building up frequencies 

of usage of code groups. Here is a typical page of one of these codes (Fig. 91). Working with 

the sparse amount of traffic within a quiet sector of the front and trying to solve a few messages in this code was really a painfully slow, very difficult and generally discouraging experience. 

On my reporting for duty to Colonel Frank Moorman, who was Chief of the whole unit, I was 

asked whether I wished to be assigned to the cipher section or to the code section. Having 

had considerable experience with the solution of the former types of cryptosystems but none 

with the latter, and being desirous of gaining such experience, I asked to be assigned to the 

code-solving unit, in order to broaden by professional knowledge and practice in cryptology. 

Little did I realize what a painful and frustrating period of learning and training I had under115 
REF ID:A63860 

C6NflBEN"'f'IAL 

taken, but my choice turned out to be a very wise and useful one. If any of you would like to 

read about my experience in this area, let me refer you to my monograph, written in 1918-19, 

entitled Field Codes Used by the German Army during the World War, copies of which are on file 

in the Office of Training Services. I will quote the last two paragraphs from my "estimate of 

the three-letter code" (on p. 65 of that monograph) and will remind you that although they 

were written over 40 years ago they are still applicable: 

"In the light of this limited experience (of less than six months with the 3-letter code) it is 

impossible to say absolutely what the degree of security offered by such a highly developed system really is. There is no doubt but that it is very great. There is no doubt but that, with 

the proper precautions, careful supervision and control the employment of such a code by 

trained men offers the highest possible security for secret communication on the field of battle. 

But no code, no matter how carefully constructed, will be safe without trained, intelligent 

personnel. A poorly constructed code may be in reality more safe when used by an expert than 

a very well constructed one when used by a careless operator, or one ignorant of the dangers of 

improperly encoded messages. This point cannot be overemphasized. It is hardly necessary 

to point out, therefore, that the proper training of the personnel which is to be put in charge of 

the work of coding messages is an essential requisite to the maintenance of secrecy of operations, 

and thus of success on the field of battle." 

So much for the German Army field codes, about which a great deal more could be said, but 

we must hurry on to the cryptosystems of some of the other armies in World War I. 

What sorts of cryptosystems did the French Army use? First, as for ciphers, they put 

much trust in transposition methods, and here is an example of one type (Fig. 91). Perhaps 

you remember one of those special route ciphers I showed you in the preceding lecture, the 

one with the diagonal that produced complexities that made the use of that route too difficult 

for the cipher operators of the USMTC. This French transposition cipher was much more 

complicated by those diagonals, and I wonder how much use was made of it by the French. 

As for codes, like the Germans, they used a small, front-line booklet called a "Carnet Reduit," 

or an "Abbreviated Codebook." Various sectors of the front had different editions, and I show 

you now a picture of one of them (Fig. 92). Then, in addition, there was a much more 

extensive code which was not only a two-part, randomized book of 10,000 four-digit code 

groups but a superencipherment was applied to the code messages when transmitted by radio 

or by "TPS," that is "telegraphie par sol," or earth telegraphy. Here is one of the tables 

used for enciphering (and deciphering) the code groups (Fig. 92), and here is the example of 

superencipherment given in the French code in my collection (Fig. 93). 

You will notice that the enciphering process breaks up the 4-digit groups in a rather clever 

manner by enciphering the first digit of the first code group separately; the second and third 

digits of the first group are enciphered as a pair; then the last digit of the first group and the 

first digit of the second code group are enciphered as a pair, and so on. This procedure succeeds in breaking up the digital code groups in such a manner as to reduce very greatly the 

frequency of repetition of 4-digit groups representing words, numbers, phrases, etc., of very 

common occurrence in military messages. My appraisal of this French Army field cryptosystem is that, theoretically at least, it certainly was the most secure of all the field systems 

used by the belligerents. 

Now how about the cryptosystems used by the British Army? First, they used the Playfair Cipher, a system of digraphic substitution considered in those days to be good enough for 

messages in the combat zone. But today, of course, its security is known to be so low that it 

hardly merits confidence for serious usage. The British also used a field code. It contained 

many common military expressions and sentences, grouped under various headings or categories, and, of course, a very small vocabulary of frequently used words, numbers, punctuation, etc. It was always used with superencipherment, the nature of which was not disclosed 

even to us, their Allies, so I am not in a postion to describe it. We did not even have a copy 

of their code-only a typewritten transcript which was furnished us quite reluctantly. This 

next slide was made by setting up in print a typical page thereof (Fig. 95). 

CONPIBEN'f'IAL 116 
REF ID:A63860 

06N'FIDEN'l'IAL 

As for the Italians, the general level of cryptologic work in Italy during the period was quite 

low, a fact which is all the more remarkable when we consider that the birthplace of modern 

cryptology was in Italy several centuries before. There appears to have been in Italy a greater 

knowledge of cryptologic techniques in the 15th and 16th Centuries than in the 19th, paradoxical as this may seem to us today. Perhaps this can be considered as one of the consequences 

of the need for secrecy which requires filing away iu. dusty archives recorffi! of cryptanalytic 

successes; but it is to be considered also that this prevents those who might have a :flair for 

cryptologic work from profiting from the progress of predecessors who have been successful 

an-Artillerie 

•lW'I Hh•lle \"On rzd .111111'11'11 kWJ 

ancla UMn aic Ant wort rtr 

ancll'ro rdn anwoi;t•ncl ugc 

Anderung sgr Anz.1hl snv 

anfangen awy • A11z11g1•, 1m ryd 

anforclom. kax Apparul uvd 

.Anfor.lt•rung rlf Arbflil kjy 

Anfragf' ukl arh(\ilPn apm 

Angabt•. sze .\111.I'•' rdm 

angeblkh aho \ r m ...... 1o,·rl..11111m:indo 

IA(.) K.1 sgt 

angegrilfen kuc Art1ll1•r1t' awv, kho 

angreifen UE'V "t>igon11 rji, uln 

Angriff rtk "Cemdhch(\ ste, agg 

Angr1rr ..... Ln·1fe11 sql "Kommandeurd. - rvj 

ADgriffs\·orbereitung rag •1e1cbte rpq 

anhal\en uyb •scbwl're sgx 

anlegen knx Arull1>rie.-Heobacbter kjn 

• A.nmar&cb, iJD ake Arliller1e· l<'eul'r rvi, ksi 

Ao.marscbweg. kn •e1gPDe8 uct, sjn 

Annll.herungsgrahen sdl •feinclliches uyc,kke 

AnnlLherungs\\·eg azs Art.llle1 io-l<'lleger aol 

Artillerie-Me.Otrup11 rei 

anrufen. kdw 

Artillerie-Slelluug . kzu 

Ansammlung rgq Artillerie-TiUgkeit . scg 

anscheinend uiy Art.-Unll'rsliltzung asr 

.AnschluB . svl 

Artillel"ieansotzen afj Verbindungsoffizior kce, rhm 

BUade Stpale ugr. rif, aeh. kqa. awd 

Figure 90. 

117 C~DEN'ffAL 
REF ID:A63860 

CONPIBHN'ffAL 

o. Elnsehrelben. 

11 17 19 6 5 14 20 21 23 15 2 8 1 22 7 18 10 3 9 19 13 24 16 4 

n a e c h Xs t e g e h e'" 1/8 s I ~ z u n g d e s 

b 'u ri d e ~ m s i e b Je n t e n ~ e z ~/ m b e 

r ~ 'tt h /n/ u b r a b e /n d's'" i n d e r......,,w a l d s 

c h e)1t k e a m'w o l f s b 'e r g e if'l. o p v e 

r t r a'-u t e f u )/h r e r a'u f d/ e r'-s t a t 

i o/n l o's u n g b'e r n k 1 a'u/a t o P°"i r a 

/ ' / ·--·~--~---- /' . ' 

d. Sigelschrift. 

eeseu utdrt sqnue nussa rweet snrom nlgde wsdid senhe ehzee ssese tshek ocdha 

lstia lbfrr ueetn dgfbr crinz rogao puete ibobe bdvar azhti enrae nenha euemm 

fnnbr kgsau mlpt 

11 17 19 6 5 14 20 21 23 15 2 8 1 22 7 18 10 3 9 12 13 24 16 4 

'n ~t'° t, d/ 

'u a"-a d e/ 

'e n/ 'r: n/ d's 'r w/ 

'/ n ' w ~l / s e s ' x t 

r/ 'u 'e' e '-• d/ 's 

o/ ' I/ 'e a °"'u/ '-- .......... --...... / ,,.,. ,,..._,. ., ...... ,...,,..-.,,.-/ ... .,,. ______ ,,.._,... ' ______ ......... ______ /' .., _____ ~~- ""ti' 

Figure 91. 

in such work. We should not be too astonished to learn, therefore, that when Italy entered 

World War I the Italian Army put its trust in a very simple variation of the ancient Vigenere 

cipher, a system called the "cifrario militare tascabile" or the "pock.et military cipher" (Fig. 

96). It, as well as several others devised by the same Italian "expert," were solved very easily 

by the Austrian cryptanalysts during the war. The Italian Army also used codes, no doubt, 

but since encipherment of such codes consisted in adding or subtracting a number from the 

page number on which a given code group appeared, the security of such systems was quite 

illusory. As late as in 1927 the same Italian "expert" announced his invention of an absolutely 

indecipherable cipher system which, Gylden says (p. 23) "still further demonstrates the astonishing lack of comprehension of modem cryptanalytic methods on his part." 

As regards Russian cryptographic work, it is known that there was, during the era of the 

last of the Czarist rulers, an apparently well organized and effective bureau for constructing 

and compiling diplomatic codes and ciphers, which had been organized by a Russian named 

Savinsky, formerly Russian Minister to Stockhohn. He saw to it that all codes and cipher in 

use were improved; he introduced strict regulations for their use; and he kept close watch over 

the cryptographic service. He also was head of a cryptanalytic activity, and it is known that 

Turkish, British, Austrian and Swedish diplomatic messages were solved. After the Bolshevik 

revolution of 1916, some of the Russian cryptanalysts managed to escape from their homeland, 

and I had the pleasure of meeting and talking with one of the best of them during his service 

with one of our Allies in World War II. He is no longer alive, but I vividly recall that he wore 

with great pride on the index finger of his right hand a ring in which was mounted a large ruby. 

When I showed interest in this unusual gem, he told me the ring had been presented him as a 

token of recognition and thanks for his cryptanalytic successes while in the service of Czar 

Nicholas, the last of the line. 

118 
-

REF ID:A63860 

But the story is altogether different as regards cryptology in the Russian Army. The Military Cryptographic Service was poorly organized and, besides, it had adopted a cryptographic 

system which proved to be too complicated for the poorly trained Russian cipher and radio 

operators to use when it was placed into effect toward the end of 1914. Here is a picture of 

that cipher (Fig. 97), which was composed of two tables, one arranged for convenience in enciphering and the other arranged for convenience in deciphering. In the enciphering table the 

CARNET REDUIT 

Telephone - T. P. .. ___ S. -- _ T. S. F. - Optique 

:Xo111 clu C.11111•1: 0 LIVE 

li1cl1r.1l1f: Q, ~ Q: 

I

-· -------· ------ --··---· -- ------ ·-·- -- -· ··- -, II est interdit de laisser aucun mot ou passage 

en clair dans les tnessages par T.S. P. ou T. V.S. , . ' 

Briilez ce earn et s 'i I est en danger d'etre pr is 

A 1.1•11 \ 111:. r 

\II: \ 111'•.t II In, 11 

\lo.I·: i \ lll'll I' 11:1.1 l.1 

.\lo.I : U lll'S ._. Jc.I II 11• 

. .\I.II I " 1:1_1 \ II .C:l.I 1 •• , 

.\I.II C 1:'11 i II 'c:llt: lo•11r 

\1.I i c: 11 .. 11 : :-.. 'i; \I Ii 1 ..... , 

\\II : II 11 .. ~ 'S i:" ... I II 

A:\I' I " C \II r :1:~n1 1 111.1 

\\S 11: C: \Z r (\I II I 1111· 

\l'li 1: 1.111 I C \IS , 1111-.. 

AllS I t: 11.111. ,. ;c:i11 1111111 

1m: IF C:ll 'i \\ ·C:\I\ .... , lllo. I' ' F I CC.\ ~ lc\I\ ........ 81.:\ Ii I ' "" \" 1

1:i1z 111111, 

81.R II c:u: z ... , ... p.11 

II~• I I l.I\ ·' ;r:\:'i ' 1•••111" 

11\S I I II: •• l.1 :11\11 \II' 

1111 \ J Cl/. .... 1111\ • , ...... I 

llCJli I\ ,, ..... \ :Ill\ ,llHll I \1111, 

Rnl I. 'Clo.II 

d ...... 

llllS 

~· Ch.Ii rlr ! :\llll HIU-:S 

Ul'I~ 

~· !"lo.I\ di• I.a '111:11 I) 1111 11111 111'11 :--.; 1l:lo.ll .•.. , 11r:1 i I u11 1•11·1111c·r Ul'l1 ~ 'tlo.'\ du 

l.h.Z el Ill lo. ~ 

11c;11 :1 

I 

NOTS -It w11ulcl n1•1•·•r that th•• 11rflclmll lr1h•nUnn of 1&>1111K ooo a.• llll' 1111111 u111r r

0

1r 1111'• rr1rn'' ha•l 1u ht• ''""'""'·I r .. r 1 he 

Ol'llllllll 1how1 &he letter O tu have• '"~·n 1uucllft1•1I. hy baml, 111 IJ W 1' 1' 

Figure 92. 

119 
REF ID:A63860 

CONflBB~\L 

C:ll 11-" I-" I\ 1-:~U:NT. l>ECllll-"fllEMENT. 

o- GS 3o- BR jO-AN AB -0!1 Ell -4!1 ND -13 I -RB 31 -IA 71-RB AD -lh ER -88 NG -66 

2-All 32-VS j2-BN AE - .1!1 ES :_ 20 NB -34 

3-SI 33-GO 73-llB AG - 1'1 NR-81 

4-BB 3\-NB 7'1-GD AB - lio GA -01 NS - 5 

.r1-NS 3.i- IS 7:-i-BU Al -78 GB -fl'i NU -27 

6-DA 36-BD j6-IE All- 2 GD -74 

7-TD 37-TA 77-Dll AN-jo GB -o'I RB -71 

8-EA 38-IB 78-AI AR -17 GI -8'i RD -12 

!I- OG 3!1-AE 79-RN AS -91 Gll-28 RB- I 

AT -011 GN - !19 RN-79 

oo-AT 4o-BT Bo-DB AU -:io GR -41; RT-21 

OJ - GA 41-SD 81-NR GS - o 

0:1-111 42-DS 82-AD BA -11 GT-98 SB -18 

o3-DN 43-DI &1-Bll BD -93 GU -33 SD -41 o~-GB 4"- El 84-GI BE -25 SB -6j o5-llN 45-BS 8.'i-ED BG -63 BA-22 SI - 3 

o6-BI 46-GR 8fi-BB BB- " BB -86 SK -51 

07-VG 47-llD 87-NA Bl -57 BD -36 SN -90 

o8-UR 48-IR 88-ER Bll-83 BG-89 SR -24 

og-AB 49-Ell 8g-BG BN-19 BI -o6 

BR -6.) Bll-96 TA-37 

lo-BT 5o-AU !JO-SN BS -45 BN-72 TD - 7 

11-BA 51 -Sii !,It -AS BT -10 BR -3o TN-62 

12-RD 52-DB !12 - llS BU -75 BS -53 TR-58 

13-ND 53-BS !t3-BD BT -4o TS -15 

14-AG 5~ - GB 9'1-IN DA - 6 

15-TS 55-UA ~:>-DS DB -52 IA -31 DA -:>5 

16-EG 56-DR 9fi-Bll DG -23 IB -38 VG- u 

lj-AR 5j-BI !lj-EB DB -69 IE -76 OB-Bo 

18-SB 58-TR !tX-GT DI -43 111-02 011-68 

19-BN 69-EB !l!t-GN Dll-77 IN -!14 UR-o8 

DN-o3 IR -48 us -4:l 

20-ES 6o-AB DR -56 IS -3.i 

21-RT 61-VN DS -95 VG-07 

22-RA 62-TN DT -26 llD-47 VN-61 

23-DG 63-BG llB-j3 vs -32 

2'i-SR 64-110 EA- 8 llN-o5 

25-BE 65-BR EB-59 llS-92 

26-DT li6- NG ED-85 llU-ti4 

27-NU 67-SB EG -16 

28-Gll 68-011 EB -07 RA-87 

29-RB 69-DB El -44 RB -29 

Figure 93. 

CONPimIN!l!IAL 120 
REF ID:A63860 

IA• lableau r.i-ccmtre a pour obJel de permettrP, .i defaul de commun1catio11 par Iii, la transmission par T. S. I'. de tnu• messages cbilTre• 

avec le Code cbiffn!, sans •1ue so•t misr en danger la ..!curi1' de "" 

Codr. 

On do•l faire emplm de ce double dnlTrement pnnr les m .... ges t~le· 

11bon1•1 11ui oeraient 1•.rbcuherement secrets ou 1mportanto. 

TB&TK. 

ConB: 

TAii.EAU. 

F.:Jetmpl• d• doable cbiJlrrn11nt 

La relhe au • ri lieu dellllin matin. 

•jb"I' 41•7

1

5 ol81il1> 81';51o •1061;, 713313 

RBjim AG 1'U AU BB TR BU GA BJ BI IS SI 

(Le pre1nit... chdl're du 1>nm11er gn1u1>e dml t-nnst1luer 11al la premiere 

tranche.) 

Pour le declu1Trc1ncnt .. re1npl,1ccr c:hdque gmupca de dL•U)r,, lett~s par 

le nombre qm c:orrco;pmd d 1 P J.'l"Oupe dan• 11• lo1ble.·u1 de ch1Rremenle 

On rctmu'e lrs gmupes du c:.1de 1•n n•lahhs.o;ant lea nomhres dP 

quatrc clulTrt•s. a parllr du c:t1111m1 nr,.rm•nl 

Ne Jl.m.us lro111S1Dl'tlr.- dt-UX ro ... 1111 n••'m(' ll'X.lt• d.an• drs "'hilTremrnts 

dlllhenls. 

Figure 94. 

Oft Abo11t Ol7 Aplnd 

OfS Dad.111111' 

Oii Behind °'°a, 

051 C.11 

OU C.ntre ... ,.... ... Eno ... ........ 

... ~ 

..., ...... OR On franl. from 

DH Fsaa1.Uae 

.&n.••b: 1.-BDIL\CTS FaOM A lalTISH ABMY PllLD CODB• 

Tl•I• IJ111'URll'lll .... 1 ... ,lfllJIC"rf)" nr II H M (1U"l'n1n11"hl, •ml ... lnll''llrll'lll 11111_\ rur lhl' (IPT'IUnal l11furn1a111111 ut' 

aml ul' 11111111 ullH'l 1'11 1111rli r 111111 -.111- duU.. II. 

all'• rr• llP 1 .. llP""111&111 """l""'"lltlP f11r 1111 il&l'eo e1 .. 111d,- Mid 

lhal II• nmlPHll• ah" cll1C"l1IN'fl 111 11u- 11mreorr. and In then• UlllJI 

SBCOND ARMY TRBNCH CODB 

1"111111011 WllaDa AllD l'llllAllll:ll 

000 lr1rn.111t (cil) 

081 ....... 

Ofll " llank Da lllM' 

OM l.uralf'd (al) 

06I 'o, Dal. 

nan '\':arth 

087 '•• DIS Ollker (a) 

Oii On 

070 Olher raa•• 071 011r 

... 07I -

Paln1. 

0Allo A:WD 0A• A'ITAC'W. 

01• Fa•1u 

07" Pilfllll1m 

07'i Cl11arll'r 

076 'l•llC!kb' 07T llear 

078 Jlenrin.\'IJll• 

079 ltet11rn 

ORO lt111h1. ORI • llai1k 

OR2 htrr<ie.> 

083 Silnee 084 Slawly 

085 Boulh 

ISi Condltlmi• ... favoqrable rar l'l"INR af RU 115 a .. aleort un 

IH What. la approxllu.1.e Vl'lut'll' af w1ad" Ill " •• url' 

Ill Appra11l11111te velaelty al wind la nillN 117 All ri......,. fur..,. •llaek 

Ill 'Und danpra• lRI a .. 111111 lw re.._d at Cthlll') 

117 " ..re 160 Ou ha. lll"flllln tu llf' l'l'kMfd 

ISi " budraPIM'd 170 " • _. " " " 

ISi Cu 171 " " bla.wn liae .. 

llD Are•• to ue ... , 173 llll'lllllftl (11111nllC'l'J J1Ai1 rylm11Pni 

Ill Yau wlll make ... •ll•k 17" n..,,.)"lmilel'll •Ill l•n.rrlll'll llll I•• lnHehn Ill Am I ( ) II/ •rel pins I.a niakco ps •UM"k 17S •• 11 l1a\P am¥1"11 

IU Tlr..::..::::rarelu.e uf - hu11111 frum :~ l~1ril!""h~~1k111::,•::db,_., uhl)"'•ll'l" 

let \\ llftl pa penoD.DeJ Lo have all ft'ady by 171 

(tlnwJ ... 

Figure 95. 

I Be1sp1el. 

a. Clt'i·a1·io tas,•abile. 

. • h ,. d c f II h I . J k Im no p <I I . . l II V \\• X y • . 0 I 2 3 4 5 6 7 s 9 

" 11111 12 1111 n 10 111s • 19:..J0212.!21~12rl262i .. 22! 2!1.10 'II "12 a., :11 ·1:; a "Jli.17SIHH041124.HH5 

b 11 1211 H In 11117 IK l'l b 20 21222, 24 2.""12n 2i 28 b 2'1 30 "II :12 :1, 84 1:; 36 b :17,839 ID4142 43444510 

' 12rn141~rn171111920 • 21 22 21 21 25 21. 27 28 29 • .-JO II "12 :~1 ~135 "16 37 • i8S94U414HH4I~1011 

d IS 14 1"116171819~'021 d 222324.:!li 2627 28 2980 d SI 32 33 34115 86 q1 38 d ,'110 414243 444:; 101112 

e 14l:i1617IS19202122 e :!3 2-12:; 26 27 28 29 3U 31 e s2 33 34 35 36 n1as39 e 404142 43444510111213 

r 1:; 161718192U21222S r 24 :z;; 2e 2i 2s 20 ao 31 a~ [ 333435S6878S3940 r ·U 42 4344451011121814 

g t6 17 tS !9 20 21222a 24 g 2:;20 2128 29 :io dt 32 s3 g 84 .1:; 36 37 SS 39 4041 g ·12434445101112 1314 tj 

b 17 11111120 2122 23 24 25 h 26 27 28 29 30 31 32 S.i d4 h 35 d637 .i83940 n 42 b 48 44 45 10 It 12 131U616 

I 1s 19 2021222324 2:;2s I 27 21:129 30 ,I ,2 31 S4115 l .ill373S39404142 IS I 4H510111213U161617 

J 19 20 2122 28 21252627 J 28 29 ao au2 dd a.rn:; 86 J '17 dS 39 40 41 42 IS 44 J 43101112lS14151617 lS 

k 20 21 22 2.'i 24 2:; 26 27 28 k 29 30 SI .-12 J, 34 35 86 37 le llS39404142431445 k 10 It 12 IS 14 1:; 16 17 lS 19 

I 21 22 2"12425 26 27 28 29 I .-10 31 32 Sd :~1.-1:; ao 37 11s I ,9 40 41 42 4.H-145 10 I 11 12 13 u 151617 lS 19 20 

m l2 2.'I 2-.1. 2U 26 27 28 29 30 m ,I S2 83 34 3:; S6 J7 SS ,9 hi 40 II i2 IS 14 1:; 10 II DI 121314151617lS192021 

n 2"124 25 26 27 2112!1 ,IQ SI n 32 83 34 :i;; 36 3; 38 89 40 n 41424H14j 101112 n 13r41:;15171s 19 202122 

0 24 25 26 27 .28 29 SO St 82 a 8, 84 .-1:; 36 37 38 3q 40 41 0 !HS 41l:i101112 lS 0 11151617lS19202122 23 

11 2;; 20 27 :!8 29 30 31 32 .n p 31.r.i 3617 38 39 1041 42 p IS 444;; 10 11 121314 p 1516171Sl92021222321 

q 2b 27 28 29 SU 31 32 33 "14 'I 115 36 87 SS 39 40 4142 43 'I 444; 10 II 1213141j 'I 16171810 20 2122 23 2425 

r 27 28 ~'II 30 31 82 33 34 :i;; r Sb .i7 Sil 39-10 41 42 4.i44 r -i.; !0111213U 1316 r 171S 1920212223242526 

• 2S 29 dO 81323d 34 s:; 36 • 373889~0·1142414445 s 10 11 12 IS 14 tr. 16 17 • IS 19 20 2122 23 24 2j 26 27 

l 29'10813283'14.i33637 I &I '19 40 4142 4S 44 4510 l ti 12 18 14 tr. 16 17 lS I 19 202122 23 24 25 26 27 2S 

u dO 31 82 d, 3485 36 37 SS u qo 40 41 -12 434443 10 11 II 121314151617lS19 u 20 2! 22 23 24 2:; 26 27 28 29 

v 8182 333485 3637 36 S9 v 40 4142 43 444510 1112 ,. Id 14 tr.1617lS19 20 v 21222"2423 26 27282930 

\\ 82 .-is 34 s:; 36 :11 38 S9 40 w 41424.HH5101112 ld w 14 lj 1617 lS 19 20 21 w 22 23 24 2j 26 27 28 29 30 Sl 

x !1-i 34 3:; 36 37 3S S9 40 41 x 42 43 44 4510 II 12 1314 x 151617 lS 19 20 21 22 x 2324 25 26 27 28 29 30 31 S2 

y 'l-U5 ~6 87 3S 39 40 4142 y 4S 444510 11 12 13 1415 y 1617181920212223 y 24 25 26 27 28 29 30 313233 

z 3:;as31SS894ou4243 z 44 45 10 1112 13141516 z 17lS192021222824 7 25 26 27 28 20 so 31 S2 83 34 

. d b c d c [ g b I . I k lmnopq r • • tuvwxy z . 0 1 2 s 4 5 6 7 s 9 

b. ScblDsseln. 

IClaNrlmtt D a 

SchlUssel 

sv 1erteBalai I lonhalvonse1ner8tellungnm 

•nmlttenmelnesl ebensweg 

Sigel ~~26~a83152SUU26342542M 3230~34~16~22 

o. Slgelaohrllt, 

Da. 3911 20:15 128:1 tr.211 41 It 20:14 2542 84 hat •on •elne• 8230 1S84 3916 2722 am 

Figure 96. 

121 

. 

• 

b 

e 

d 

e 

r 

g 

h 

l 

J 

k 

I 

m 

D 

0 

p 

q 

r 

• 

I 

u 

v 

w 

x 

y 

z 

. 
REF ID:A63860 

C6NPIB:tffft'IAL 

letters of the Russian alphabet (33 in all) appear in the topmost row of characters, the 2-digit 

groups, in random order within each of the 8 rows below the top row, are their cipher equivalents. These rows therefore constitute a set of 8 cipher alphabets, these alphabets being preceded by key numbers from 1 to 8 in random order. Both the cipher equivalents and the indicators were subject to change. Indicators were used to tell how many letters were enciphered 

consecutively in each alphabet, the indicator consisting of one of the digits from 1 to 9 repeated 

five times. The alphabets were then used in key-number sequence, enciphering the first set of 

letters (5, 7, etc., according to the indicator) by alphabet 1, the next set by alphabet 2, and 

so on. After the 8th set of letters, which was enciphered by cipher alphabet 8, one returned 

to cipher alphabet 1, repeating the sequence in this manner until the entire message had been 

enciphered. In enciphering a long message the cipher operator could change the number of 

letters enciphered consecutively by inserting another indicator digit repeated five times and 

then continuing with the next alphabet in the sequence of alphabets. The cipher text was 

then sent in 5-digit groups. The use of the deciphering table hardly requires explanation but 

this question may be in order: Why the aversion to the use of zero and to the use of double 

digits such as 11, 22, 33, etc.? This probably was thought to be helpful to the telegraph operators as well as to the cipher clerks in straightening out errors in transmission and reception. 

I have told you that this cipher system proved too difficult for the Russians to use, and I 

think you can see why. It was so difficult that messages had to be repeated over and over, 

with great loss of time. It is well known to all historians by this time that the Russians lost 

the Battle of Tannenberg in the autumn of 1914 largely because of faulty communications. 

Poor cryptography and failure to use even the most simple ciphers properly on the field of 

battle, and not brilliant strategy on the part of the enemy, was the cause of Russia's defeat in 

Russischer Sprungchlft"re. a. Ch.lflrant. 

<> .1 ii u l' ;i P :i: .1 11 1: ::i ll 11 o 11 I' 1• ·r l •I• ".:: 11 •1 111 111 i. IO n 1. 'L i.1 II 1 " 

3filMfil~M~llOO~U~~~~~~MOO~OOMOO~OOIBM~~~UMMM3 

lfilfilfilW~oonoo~~~M~~~~MIB~OOOO~~~MMM~~n~M~l 

4ffi~filMfilUM~~mIB~~OOOOOO~IB~~uoo~~n~~H~~M~004 

5~~~~IBMOOIB~MMnWMOO~OO~WWllMW~~MOOU~~~~fil5 

6~filn~~IB~M~~~ffiM~~MM~M~~MMIB~llOO~OO~~W~6 

7~M~~~~~MMn~~~~UMfilmIB~OO~~OO~MOO~UOOIBMM7 

suoo~ura~ooMfil~~~~~oo~~w~~~fil~noo~unoo~~~ms 

2~00filOO~OOfil~W~~fil~OO~MMn~M~OOWIB~W~~MM00~~2 

•abwgde~eiklmnoprstufhc~i~~~~iYJiy• ,_.. ~ .... 

s::: 

b. Dechiflrant. 

"llIBMffiWUIBWfil~H~~~~~fil~M~OO~~OO~~~~~~~~M~~M* 

3 :;i: Dt i • . '.L • • • 10 "< • • • • • 11. } • e • ;[ 'I H 11 • 0 11 JI JI • • • 111 3 

1. To• ,'L, ,(1 pf.L131:11) l\ll,, X11'1 l•;tO, i,,, fl,, ,1 

4..·r. '"· e.J". Bllilsts •• ·r,. ,1 1.t1n. U. 1. ·I,.10~·111Ln. e •• 4 

5 x 3 0 • y • ;t II • r • • IO !' • fl • • '[, m Id 'L • • • • • II • Ill • • B • ::I 5 

6 f, a y 11 • n 111 • • 11 11 .1 • 1 nt • 6 • ,. x n • m r • 1: • • n • • • •I• I' 6 

7 • Ll • • • b l • • 1• JI • )I .1 • It " • d • • • • Ill a lit l • H • • u :!. • e • 7 

8 .L ;t JO • 1' Ill , , , ! • . M , , , U , , , , IC e II Ll , , • , , 't 11 , 'L II 3 8 

2.iuu .'b •• Hai: •• ul •• 111 n11. ~· •• n •••••• 1 ••••••• 2 

*OOMMOOfil~MM~M~oonnnu~~~Wfil~~M~OO~~M~OOMOOOOITTOO• 

3 J l ti •!• 6 I. •• 1 •• 

1 e , , 1(1 ll , lit IO , , , 

4 ••• 11 ••• 1· II m • 

5 •• ll •• 1 •• • II Ii: 

6. ll •• J • 11 •• 

G SI n 

• • • • I\: 

• • .1: HI • 

1: • lll • x 

• 'I • • .H 

• r • 

7. , JI , , 'I ,, .. 8 U I o Ill JI • I' t) I , n i. I 

..r11 •• i.11111.11 

• • • 1' H • II • n • • II 

e • 3 

~ • 1 

• •••• p'L41 •• o •••• 1t4 

• 1. • •I• i . nt • T a • u ,. • • • e • 5 

0 :II: "h • Iii 11 JI • • .I • It\ • • • 6 

1 • • • u ll: • It l 

H ! • • 

2 e •• o 11 J 1 •••• ll •r • II • :1 ·J. • • f'i }I • 6 

I Ill 1, , X 7 

• •I• .1: • I 8 l 1 ....... 2 

Figure 97. 

122 
REF ID:A63860 

CONfi IODENTmL 

that and in subsequent battles. The contents of Russian communications became known to 

the German and Austrian High Commands within a few hours after transmission by radio. 

The disposition and movements of Russian troops and Russian strategic plans were no secrets 

to the enemy. The detailed and absolutely reliable information obtained by intercepting and 

reading the Russian communications made it very easy for the German and Austrian commanders not only to take proper counter measures to prevent the execution of Russian plans 

but also to launch attacks on the weakest parts of the Russian front. Although the Russian 

ciphers were really not complicated, their cipher clerks and radio operators found themselves 

unable to exchange messages with accuracy and speed. As a matter of fact, they were so inept 

that not only were their cipher messages easily solved but also they made so many errors that 

the intended recipients themselves had considerable difficulty in deciphering the messages, 

even with the correct keys. In some cases this led to the use of plain language, so that the 

German and Austrian forces did not even have to do anything but intercept the messages and 

translate the Russian. To send out dispositions, impending movements, immediate and longrange plans in plain language was, of course, one cardinal error. Another was to encipher only 

words and phrases deemed the important ones, leaving the rest in clear. Another cardinal 

error, made when a cipher was superseded, was to send a message to a unit that had not yet 

received the new key and, on learning this, to repeat the identical message in the old key. 

I suppose the Russians in World War I committed every major error in the catalog of cryptocriminology. No wonder they lost the Battle of Tannenberg, which one military critic said 

was not a battle but a massacre, because the Russians lost 100,000 men in the 3-day engagement, on the last day of which the Russian commander-in-chief committed suicide. Three 

weeks later another high Russian commander followed suit, and the Russian Army began to 

fall apart, completely disorganized, without leadership or plans. Russia itself began to go 

down in ruins when its Army, Navy and Government failed so completely, and this made 

way for the October revolution, ushering in a regime that was too weak to put things together 

again. The remnants were picked up by a small band of fanatics with military and administrative ability. By treachery, violence and cunning, they welded together what has now become a mighty adversary of the Western World, the USSR. 

I have left to be treated last in this lecture the cryptosystem.s used by the American Expeditionary Forces in Europe during our participation in World War I. 

When the :first contingents of the AEF arrived in France in the summer of 1917, there were 

available for secret communications within the AEF but three authorized means. The first 

was the extensive code for administrative telegraphic correspondence, the 1915 edition of the 

War Department Telegraph Code about which I've already told you something. Although it 

was fairly well adapted for that type of communication, it was not at all suitable for rapid and 

efficient strategic or tactical communications in the field, nor was it safe to use without a 

clumsy superencipherment. The second cryptosystem available was that known as the repeating-key cipher, which used the Signal Corps Cipher Disk, the basic principles of which were 

described as far back as about the year 1500. The third system available was the Playfair 

Cipher, which had been frankly copied from the British, who had used it as a field cipher for 

many years before World War I and continued to use it. In addition to these authorized 

means there were from time to time current in the AEF apparently several-how many, no 

one knows-unauthorized, locally improvised "codes" of varying degrees of security, mostly 

nil. I show one of these in this slide (Fig. 98) and will let you assess its security yourself. 

Seen in retrospect, when the AEF was first organized it was certainly unprepared for handling secret communications in the field; but it is certain that it was no more unprepared in 

this respect than was any of the other belligerents upon their respective entries into World 

War I, as I've indicated previously in this lecture. This is rather strange because never before in the history of warfare had cryptology played so important a role as a consequence of 

advances in electrical communications technology. When measured by today's standards it 

must be said that not only was the AEF on its arrival in Europe wholly unprepared as to secret 

123 
CO~fflAL 

REF ID:A63860 

Beadquarten 

62D4 Intant17 Brigade 

26th Division 

A.E.F. 

Franca. 17 ~ril 1918. 

'nle toll~wi:ag oode tor oomnunicatioDS between Companie•. B&ttalicma. 

Regiment• and Headquarter& 52nd Infant1"7 Brigade will be effeotive 18 .6.pr11 

1918• 12 o'clock. 

CASPALTil;,'S 

KILI.ED •••••••••••••••••.••.••••••••••••• Strlke out 

SERIOUSLY WOUJ1DEDeo•••••••••••••••••••••Baae on ball• 

SLIGHTLY WOOllDEl>e•••••••••••••••••••••••H1t by pitched ball 

ACCIJID5'ALLYWODJIDEl).,, ••••• , ••••••••••• .Ba;Udr 

ltlSBIJICJee•••••••••••••••••••••••••••••••Pv.t outs C~:W.CISSIOIED OFFICERo•••••••••••••••••••J&ajor 

EllLIS'!BD lll'lle•••••••••••••••••••••••••••IO.no~• 

C!.PTtJBES 

HAVE TAKDI (:tlo) __ PRISOllEBSo•• •••••• •••• Stolen Baaea. ____ (NO; 

-·· Lest (NCl Pli.ISOllERS ............. Left OD.... (.;.~i 

!IA.VE LOST l\4A.CHI?m GUE ••••••••••••••••••••••••••• Brrora 

BAVB T.AKIJl KA.CllllE GUJIB•••••••••••••••••••••·••••.lB•i•t• 

WE WERE BOMBABDED BY YI1'REN\7ERFEBS ••••••••••••••• Johnaon ua111g apit ball 

'WE BOllBAlUED WI'!H '!RENCH l\llORTABS •••••••••••• ••• •• Leonard. uai:ag alow ball 

n BOllB6llDED nm STOKES KOBTilS •••••••••••• , , ••• Leozaard. uaillg api t ball 

n BOllJIABQ!!!D WIS 37 :r.1.M. CAlJOJr, ••••••••••••••••• Lecmal'Cl uai:ag a CUl'V8 

1'?.BBD Olf Br lllAOHIJIE GUNS ••••••••••••••••••••••••• Jo.lmsoa u.ill&' taat ball 

l'IBED Wl'!H MACHI:tlE GUJIS •••••••••••••••••••••••••• Leonard. UBill&' faat bali 

VEWEBE 'DRDEB BOJIJIABJllEll~ •••••••••••••••••••••••• wagner at bat 

WE WEBE UNDEB HFAvr BO.l'ilBABllDJI ••••••••• , •••••••• Wagner mooke6 a home :::'l'.D 

D WED OlllDER MOlmRA.TB BOMBA~ ••••••••••••••• wape.r triplfd. 

VIE W.EBE OBDEll LIGB'J! BCJllB~. • • • •. •. •• •••••••• Wapa d.ouble4 

WE WERE BOJIBARDED Wl'!H GAB •••• •••••••••••• •••• • •• WBpel' siiaglecl 

ENEllf BEGISTBi.,IOllT PIBEo•••••••••••••••••••••••••WllgDel' ban~e4 

'IE BOllBAllDEDa•••••••••••••••••••••••••••••••••·••Cob~ at bat 

n BOllBABDED HaVILY ••••••••••••• · •••••••••••••••• c obb lmooked. a MILO l'll'I 

WE BOllBABDED ll>DERA.TELYe•••••••••••••••••••••••••Cobb tripled 

WE 30.llBABDl!lD LIGH~Yo••••••••••••••••••••••••••••Cobb 4oubled 

WE BOllllABDED WI!l!R OAS••••••••••••••••••••••••••••Cobb ai11Bled. 

BEGISTBATIOJI PIBB (OUBSt••••••••••••••••••~··••••Cobb bunted. 

BABBAGE Bl!QUESTED ~··· •••••••••••••••• ________ fanned 

OUJl AMILLERJ' UID DOWN A ll11R4GE. • • .. • .... • .. , .. Sent ila a p\nch 1'1 t. ti!!! 

_:.u:im;r.r.ammn 

JIO UBUSUAL 'BEllCH BVEll'l8··•••••••••••••••••······Game oalle~. raju QUIB! l>AYe• • •• •• •• ••• •. •. • •••• •. • ••• •• ••••••••••• oame oalle':l darl':!l..?sa 

ACTlv.B DlY ••••••••••••••••••••••••••••••••••••••• :&Zt.a 'DD!NJ g\ICE 

~ ERBll!' IS J>OIBG TRENCH M>BIC at •••••••••• He 1• wa"'llliDg '•P 

WE ABB J>OlJJG 'BDCll WOllK at •••. • •••••••• we an wam•.:ig .. l' 

Figure 98. 

CONFIDENTIAL 124 
REF ID:A63860 

OON.FIBFINH1.Y. 

communication means and methods and as to cryptanalysis, but for a limited time it seemed 

almost hopeless that the AEF could catch up with the technical advances both sides had made, 

because their British and French allies were at :first most reluctant to disclose any of their 

hard-earned information about these vital matters. 

Nevertheless, and despite so inauspicious a commencement, by the time of the Armistice 

in November 1918, not only had the AEF caught up with their allies but they had surpassed 

them in the preparation of sound codes, as may be gathered from the fact that their allies had 

by then decided to adopt the AEF system of :field codes and methods for their preparation, 

printing, distribution, and usage. 

Just as the invention of Morse wire telegraphy had a remarkable effect upon military communications during the American Civil War, as related in the preceding lecture, so the invention 

of radio also played a very important role in :field communications during World War I. 

Now, although it can hardly be said that all commanders from the very earliest days of the 

use of radio in military communications acutely recognized one of the most important disadvantages of radio-namely, the fact that radio signals may be more-or-less easily intercepted 

by the enemy-it was not long before the consequences of a complete disregard of this 

obvious fact impressed themselves upon most commanders, with the result that the transmission of plain language became the exception rather than the rule. This gave the most momentous stimulus to the development and increased use of cryptology that this service had ever 

experienced. 

Let us review some of the accomplishments of the Code Compilation Service under the Signal 

Corps, AEF. It was organized in January 1918, and consisted of one captain, three lieutenants 

and one enlisted man. Until this service was organized, that is, from the summer of 1917 

until the end of that year, the AEF had nothing for cryptocommunications except those three 

inadequate means which I've mentioned. When it had been determined that field codes were 

needed, little time was lost in getting on with the job that had to be done. Since I had no 

part in this effort, I can say, without danger of being charged with impropriety, that the Code 

Compilation Service executed the most remarkable job in the history of military cryptography up to the time of World War II. 

The :first work entrusted to it was the compilation of a so-called "Trench Code," of which 

1000 copies were printed, together with what were then called "distortion tables." These 

were simple monoalphabets for enciphering the 2-letter groups of the code. I will show you a 

picture of a page of this code (Fig. 99) and of one of the "distortion tables" (Fig. 100). The 

danger of capture of these codes was recognized as being such that the books were not issued 

below battalions. Hence, to meet the needs of the front line, a much smaller book was prepared 

and printed, called the "Front Line Code." Distortion tables, 30 of them in all, were issued 

to accompany this code, of which an edition of 3,000 copies was printed. But the code was 

not distributed, because a study of its security showed defects. The truth is that AEF cryptographers with personnelin experienced in cryptanalysis were groping in the dark, with little 

or no help from allies. Finally, the light broke through: the Code Compilation Service began 

to see the advantages of that German 3-letter randomized 2-part code I've told you about, the 

one called the Satzbuck. Here, then, was the origin of the Trench Codes which were :finally 

adopted and used by the AEF, when it was decided that copying and bene:fitting from the 

experience of German code compilers was no dishonor. But the AEF then went them one better, as you shall now learn. The :first code of the new series of the AEF field codes was known 

as the "Potomac Code"; it was the :first of the so-called "American River Series," and it appeared on 24 June 1918, in an edition of 2,000 copies (Fig. 101). It contained approximately 

1, 700 words and phrases and, as the official report so succinctly states, "was made up with a 

coding and decoding section in order to reduce the work of the operators at the front." The 

designation "two-part," "randomized," or, least of all, the British nomenclature, a ''hatted" 

code, was still unknown-but the principle was there nonetheless. Let us see what the official 

report goes on to say on this point; let us listen to some sound common sense: 

125 OON.PIBBN'l'IAL 
REF ID:A63860 

13-C 

51 OB.. . .. Advance 

52 OC. .. . .. Ad,,·aaacc guard 

53 OD. . • Ad\•ancing 

5-1 OF. .Ad\•antagc 

55 OG ...... Acroplam• (s) 

56 OK .... Acroplam· uhsl'rvation 

57 OL. . .• Acroplnnc wirclcl>' 

58 01\1 ..... After 

59 ON ...... Afternoon 

GO OP. ·······''gain 

61 OR .....• Against 

b2 OS ...... Age 

63 OT ......... '\hn 

G-1 OV ...... Air 

G5 OW ... -Al 

66 OZ Alert 

67 UB .\II 

68 UC . . .. .\ 11 cl .. •ar 

13-C 

69 CD .... All communicataon hni. been cut (with) 

70 UF ....... \11 is well 

71 UG.. . . All of your messages ha\·e been received 

72 UH ....... \II ready 

71 UK. . . .\II rt•ll1 rned 

7' UL ...... All right 

75 UM... ..Alone 

76 UN ........ Along 

77 lJP ....... Al read) 

18 UR ...... Also -ed-1721 -HEG 

79 US ......... Altcr -ing-1999-LYW 

61 UT ...... .Altogether -ly-2083-.1\IUZ 

81 UV.. . ... ..\l"'!ayi. -ment-2121-NEG 

82 UW .. Am 

81 UZ... . . Am having 

84 YB ...... Am I 

85 YC ....... Am not 

86 YD.. . ... ,\ n1hulance (a) 

67 YF. . . .Ambush 

88 YG ...... Ammunition 

81 YB ....... Ammunition depot (s) 

tO YK ....... Ammunition exhausted 

91 YL ..... Ammunition for 75 m.m. Field Gun, reduced 

92 YM ....... Among [charge, explosh·e projectile 

93 YN ........ Amplifier 

H YP ......... An 

95 YR ........ -Ance 

91 YS ......... And 

97 YT ....... Angle 

98 YV ......... Annihilate 

It YW ........ Announce 

OI YZ ........ Annoy (7) 

Figure 99. 

126 
-

REF ID:A63860 

2-n 

TRIS TABLE MUST NOT FALL INTO THE HANDS OF 

THE ENEMY. 

l. If destroyed to pre\·ent capture, report will be made to 

the omcc to which its return is ordered. 

2. This tabll• will be used from 3 a. m ....................................• 

to :; :1. m ................................... , afkr which .it will be 1·cturnl•d in ~eaJ,•d l'n,·cloJ>e to .................................................. . 

ES CIPHER 

A B C D E F G H I K L M N 0 p R s T u v " y z 

h o m s v a r e c z k n r 1 u W' y i t b d p g 

DE('IPHER 

a b c d e r g h i k 1 m n o p r s t u v • y z 

F V I W H N Z A T LOCMBY G D u p E R s K 

Ii'·~ \\ urcl . . . . . . . . . . . . . . ..... . 

St.'r\ ;,.,. mc.·~'"IC"' ........... . 

Figure 100. 

127 CONflMN'f'IAL 
ABE .• Falling hack 

ABF ... Heavy 

ABG ... Message received 

ABK ... Supply 

ABM ..• Have you received 

ABO ••. Bombardment 

ABP ..• Barrage 

ABS ••• Battalion 

ABV ... Automatic 

ABW ... Must be 

ABX .•• Truck 

ABY .•• Received 

AFC •.• Cannot 

AFD .•. One 

AFJ ••. Turn 

REF ID:A63860 

l>HCOl>INll 

APE ... Rclief completed 

APF .. Retire 

APJ ... Premature 

APN .•• lmpossible 

APO .•. Withdraw 

APU .•. Machine gun ammunition 

APW ..• E 

APX .•• Remove 

APY •.. Moving 

ASB ..• 92 

ASF .•. Shell 

ASG ••• T 

ASK ••. Has not been 

ASM ..• Gas is being blown back 

ASO .•• Control 

AFM ••• Machine gun emplacement 

AFO .•. Enemy 

ASP ..• Removed 

ASV .•• Keep 

AFR •.. 7 

AFV ..• 18 

AFX ••• Smoke 

AFY •.• Stop 

AGE .•• Diminish 

AGF .•• -en 

J:GH .•• Picket 

AGK .•• Stay 

AGL .•• Field buzzer 

AGN ••. In communication with 

AGO ••• Question 

4GU .•• Lieutenant 

AGY ••• Emplacement 

AMC ••• Further 

AMG ••• Wounded 

AMK ••• We are losing heavily 

AMO ••• At close quarters 

.AUP ••• Confirm 

AMS .•• Our first line 

AMV ••• -ate 

AMX ••• Might 

AMY ••• Evident 

AND ..• Battall.on 

ANF ... During the night 

ANG .•• Fifth 

ANK .•• All stations 

ANP .•• Observer 

ANO ••• 31 

ANS ••• Consider 

ANW ••• 36 

ANX ••• Your 

ANY ••• Within 

APB .. Bombproof 

Figure 101. 

128 

ASX ••• Surprise 

ASY ••• (Null) 

AUB ••. Runner 

AUF •.• Must have 

AUG ..• Condition 

AUK .•• Safety 

AUM ••• Minute 

AUP ..• Rescue 

AUS .•• Point 

AUW ••• v. B. rocket 

AUX .•• On the right 

AWB ••• Sometime 

AWC .•• Require 

AWE .•• Barricade 

AWG ••• O'clock 

AWK ••• Light signal 

AWO .•• Double 

AWP ••• Still 

AWS ... Lengthen 

AWX .•. Will signal by 

AWY .•• Will not 

AXB .•• Forcing 

AXF .• Magazine 

AXG ••• Trenches 

AXM ••• 45 

AXP .•. Send 

AXS .•• Moment 

AXV .•• Your 

AXW .•. Last night 

AXY .. Going 

BAD ..• Advance 

BAF .. Afternoon 

~AG D1v1s1on hPadq~1~t~:fi 
REF ID:A63860 

OONFfBEN'flAL 

"The main point of difference from other Army codes lay in the principle of reprinting these 

books at frequent intervals and depending largely upon the rapidity of the reissuance for the 

secrecy of the codes. This method did away with the double work at the front of ciphering 

and deciphering, and put the burden of work upon general headquarters, where it properly belonged. Under this system one issue of codes could be distributed down to regiments; another 

issue held at Army Headquarters; and a third issue held at General Headquarters. As a matter 

of record this first book, the Potomac, was captured by the enemy on July 20, just one month 

after issuance, but within two days, it had been replaced throughout the entire Army in the field." 

The replacement code was the Suwanee, the next in the River Series, followed by the Wabash, 

the Allegheny and the Hudson, all for the American First Army. In October 1918 a departure 

in plan was made, and different codes were issued simultaneously to the First and Second 

Armies. This was done in order not to jeopardize unnecessarily the life of the codes by putting in the field at one time 5,000 or 6,000 copies of any one issue. Thus the Champlain, the 

first of what came to be called the "Lake Series," for the Second Army, was issued with the 

Colorado of the "River Series" for the First Army; these were followed by the Huron and the 

Osage, the Seneca and the Niagara, in editions of 2,500 each. 

In addition to the foregoing series of codes were certain others that should be mentioned, as 

for example, a short code of 2-letter code groups to be used by front line troops as an emergency 

code; a short code list for reporting casualties; a telephone code for disguising the names of 

commanding officers and their units, and so on. But there was in addition to all the foregoing, one large code that must be mentioned, a code to meet the requirements for secure 

transmission of messages among the higher commands in the field and between these and GHQ. 

This was a task of considerable magnitude and required several months' study of messages, 

confidential papers concerning organizations, replacements, operations, and of military documents of all sorts. The code was to be known as the AEF Staff Code. In May 1918, the 

manuscript of this code was sent to press, and the printing job was done in one month by the 

printing facilities of the AEF Adjutant General. Considering that the code contained approximately 30,000 words and phrases, accompanied by code groups consisting of 5-figure groups 

and 4-letter groups, the task completed represents a remarkable achievement by a field printing 

organization, and I believe that this was the largest and most comprehensive codebook ever 

compiled and printed by an army in the field. More than 50,000 telegraphic combinations 

were sent in tests in order to cast out combinations liable to error in transmission. One thousand copies of this code were printed and bound. With this code, as a superencipherment 

system, there were issued from time to time "distortion tables." There remains only to be 

said that the war was over before this code could be given a good work out, but I have no 

doubt that during the few months it was in effect it served a very useful purpose. Moreover, 

the excellent vocabulary was later used as a skeleton for a new War Department Telegraph 

Code to replace the edition of 1915. 

One more code remains to be mentioned: a "Radio Service Code," the first of its kind in 

the American Army. This was prepared in October, to be used instead of a French code of 

similar nature. Finally, anticipating the possible requirement for codes for use by the Army 

of Occupation, a series of three small codes, identical in format with the war time trench codes 

of the River and Lake series, was prepared, and printed. They were named simply Field Codes 

No. 1, 2 and 3 but were never issued because there turned out to be no need for them in the 

quietude in Germany after the Army of Occupation marched into former enemy, but now very 

friendly, territory. 

I will bring this lecture to a close now by referring those of you, who might wish to learn 

more about the successes and exploits of the cryptographic organization of the AEF in World 

War I, to my monograph entitled American Army Field Codes in the American Expeditionary 

Forces during the First World War, Government Printing Office, 1942. Copies are on file in 

the Office of Training Services. In that monograph you will find many details of interest 

129 
REF ID:A63860 

OONFIBEN'HAL 

which I have had to omit in this talk, together with many photographs of the codes and ciphers 

produced and used not only by the AEF but also by our allies and enemies during that con-

:ftict. 

* * * 

In Lecture IV two USMTC cipher messages were given and I said that their solutions would 

be presented at the conclusion of the next lecture. Here they are, both being from Major 

General Buell to General-in-Chief Halleck, relating to the relief and reinstatement of Buell. 

Louisville, Ky., September 29, 1862 

Maj. Gen. Halleck, General-in-Chief: 

I have received your orders of the 24th inst., requiring me to turn over my command to Maj. 

Gen. G. H. Thomas. I have accordingly turned over the command to him, and in further 

obedience to your instructions, I shall repair to Indianapolis and await further orders. 

General Halleck: 

D. C. Buell, 

Major-General 

Louisville, Ky., September 30, 1862 

I received last evening your dispatch suspending my removal from command. Out of a sense 

of public duty, I shall continue to discharge the duties of my command to the best of my ability 

until otherwise ordered. 

130 

D. C. Buell, 

Major-General 
REF ID:A63860 

Lecture VI 

This, the sixth and :final lecture in this series on the history of cryptology, will be devoted 

to a presentation of the events of importance in that history from the end of World War I to 

the end of World War II. It would be entirely too ambitious a project even to attempt to 

compress within a lecture of only fifty minutes all that should or could be told in that segment 

of our history. Briefly, however, it can be said that the most significant events during that 

quarter of a century were directly concerned :firstly, with the advances made in the production of more complex mechanical, electrical, and electronic cryptographic apparatus and, 

secondly, with the concomitant advances in the production of more sophisticated cryptanalytic 

apparatus in order to speed up or to make possible the solution of enemy communications 

produced by these increasingly complex crYPtographic machines. These two phases are interrelated because, to use a simple analogy, cryptography and cryptanalysis represent the obverse and reverse faces of a single coin. 

As to advances in the development and use of more effective crwtographic apparatus I 

will only note at this point a comment which General Omar Bradley of World War II fame 

makes in his very interesting book, A Soldier's St;ory: 1 

Signal Corps officers like to remind us that "although Congress can make a general, it takes 

communications to make him a commander." 

It is presumptuous to amend General Bradley's remark but this is how I wish he had worded 

it: 

Signal Corps officers like to remind us that "although Congress can make a general, it takes 

rapid and secure communications to make him a good commander." 

This will in fact be the keynote of this lecture. In other words, communication security, or 

COMSEC, will be its main theme and the one I wish to emphasize. 

But before we take up the cryptographic history of the years between 1918 and 1946, perhaps a bit more attention must be devoted to events and developments of cryptanalytic significance or importance during this period. By far the most spectacular and interesting of 

these are the ones which were so fully and disastrously disclosed by the various investigations 

conducted by the Army and Navy very secretly while World War II was still in progress, and 

both secretly and openly after the close of hostilities. The investigations were intended to ascertain why our Army and Navy forces in Hawaii were caught by surprise by the sneak attack 

on Pearl Harbor by the Japanese on the morning of 7 December 1941. They were also intended to ascertain and pin the blame on whoever was responsible. I don't think I should 

even attempt to give you my personal opinion on these complex questions, which were studied 

by seven different boards within the Services and :finally by the Joint Congressional Committee 

on the Investigation of the Pearl Harbor Attack. I mentioned the latter investigation in my :first 

lecture and now will add to what I said then. The committee began its work early in September 

1945 with secret hearings, but on 70 days between 15 November 1945 and 31May1946, open 

hearings were conducted, in the course of which some 15,000 pages of testimony were taken and 

a total of 183 exhibits received, incident to an examination of 43 witnesses. In July 1946 the 

committee put out a :final report of 580 pages containing its :findings, conclusions and recommendations. The report was accompanied by a set of 39 volumes of testimony and exhibits. 

The report was really not a single report: there was one by the Majority (signed by six Dem1 New York: Henry Holt and Co., 1951, p 474. 

131 C~DBffffAL 
REF ID:A63860 

ocratic and two Republican members), and one by the Minority (signed by two Republican 

members). The Minority Report was not nearly as long as that of the Majority, but it brought 

into focus certain troublesome points which still form the subject of acrimonious discussions 

and writings by those who believe the attack was "engineered" by President Roosevelt and 

that certain authorities in Washington were as culpable as were the principal commanders in 

the Army and in the Navy in Hawaii. 

For this lecture, however, it is an interesting fact that both the Majority and Minority Reports contain glowing tributes to the role played by COMINT before and during our participation in World War II. In my first lecture, I presented a brief extract in this regard, taken 

from the Majority Report; 2 but here is what the Minority Report says on the subject: 3 

"Through the Army and Navy intelligence services extensive information was secured respecting 

Japanese war plans and designs, by intercepted and decoded Japanese secret messages, which 

indicated the growing danger of war and increasingly after November 26 the imminence of a 

Japanese attack. 

With extraordinary skill, zeal, and watchfulness the intelligence services of the Army Signal 

Corps and Navy Office of Naval Communications broke Japanese codes and intercepted messages between the Japanese Government and its spies and agents and ambassadors in all parts 

of the world and supplied the high authorities in Washington reliable secret information respecting 

Japanese designs, decisions, and operations at home, in the United States, and in other countries. 

Although there were delays in the translations of many intercepts, the intelligence services had 

furnished to those high authorities a large number of Japanese messages which clearly indicated 

the growing resolve of the Japanese Government on war before December 7, 1941." 

Although references to COMINT abound in the Report of the Majority as well as in the 

Report of the Minority, there are also many references having to do with COMSEC in both 

Reports, as well as in the 39 accompanying volwnes of testimony and exhibits. Some technical 

misconceptions with regard to those subjects are there, too, and it is quite comprehensible that 

there should be some on the part of laymen, but to encounter a serious one in a book by an 

experienced high-level commander in World War II is a bit disconcerting. Listen to this paragraph from a recent book by General Wedemeyer, who was one such commander:' 

"The argument has been made that we could not afford to let the Japanese know we had broken 

their code. But this argument against a Presidential warning does not hold water. It was not 

a mere matter of having broken a specific code; what we had done was to devise a machine which 

could break any [author's emphasis] code provided it was fed the right combinations by our 

extremely able and gifted cryptographers. The Japanese kept changing their codes throughout 

the war anyway. And we kept breaking them almost as a matter of routine." 

I don't know where General Wedemeyer obtained his information about that wonderful 

machine he mentions. I imagine that there are many other persons who think there is such a 

machine because of all they hear and see about those marvelous "electronic brains" which are 

capable of performing such amazing feats in solving all kinds of problems. I daresay I won't 

be wrong in assuming that many of you do indeed wish there were such a machine as that 

mentioned by General Wedemeyer. Nobody doubts that electronic digital computers can do 

lots of things in cryptologic research, and many persons speculate on the role they may play 

in their possible applications in connection with such research in future wars. 

But let's leave such speculations, interesting as they may be, and continue with our history 

of past applications. Let's first dispose of some comments in the COMINT area of that history, 

not only on the events preceding the Pearl Harbor attack, but also on the military, naval and 

air operations which ensued in the Pacific as well as in the European Theatre. 

You will recall that in my first lecture I called to your attention an article which appeared 

in the 17 December 1945 issue of Time magazine and which was based upon a letter that the 

2 The 79th Congress, 2nd Session, Senate Document No. 244, Washington: The Government Printing 

Office, 1946, p. 232. 

a Ibid, page 514. 

"Wedemeyer, General Albert C.; Wedemeyer Reports, Henry Holt and Company, New York: 1958, p. 430. 

132 
REF ID:A63860 

late General Marshall wrote to Governor Dewey, Republican candidate for President in the 

1944 campaign. Here's how the two principals looked at that time (Fig. 102). In the letter, 

which was written on 27 September 1944 and hand-carried by Colonel Carter W. Clarke, a 

high-level officer in Axmy G-2, to Governor Dewey, General Marshall begged the Governor to 

say nothing during the campaign about a certain piece of very vital information which had 

become known to the Governor, it having been "leaked" to him by persons unknown and unauthorized to disclose it. The information dealt with the fact that U.S. Government authorities had been reading Japanese codes and ciphers before the attack on Pearl Harbor. The 

points which General Marshall wanted to convey were that not only was the "leaked" information true, but much more important were the facts that (1) the war was still in progress; 

(2) the Japanese were still using certain of the pre-Pearl Harbor cryptosystems; and (3) the U.S. 

Government was still reading highly secret Japanese messages in those systems, as well as 

highly secret messages of other enemy governments. Therefore, it was absolutely vital that 

Governor Dewey not use the top secret information as political ammunition in his campaign. 

Figure 102. 

After merely glancing over the first two paragraphs of the letter, Governor Dewey handed 

it back to Colonel Clarke with the comment that he did not wish to read any further, whereupon there was nothing for Colonel Clarke to do but return immediately to Washington. 

General Marshall then made certain changes in the opening paragraphs of the letter and again 

Colonel Clarke hand-carried it to the Governor, who then read the whole of it. In my first 

lecture I said that I might later give further extracts from Time's account of this episode, but 

there isn't time. Instead, however, I've put the whole account in Appendix I to the present 

lecture. The Marshall-Dewey correspondence is so important in cryptologic history that I 

have deemed it useful to put the whole of it in Appendix II. 6 

The information disclosed during the various official investigations of the attack on Pearl 

Harbor, so far as concerns the important COMINT achievements of the Axmy and the Navy 

before and after that attack, was classified information of the very highest security level, and 

the disclosures were therefore highly detrimental to our national security. Much has been 

written about them since the end of hostilities and although all of that formerly top secret 

1 See p. 118. 

133 COHFIBBH'HAL 
REF ID:A63860 

CONFll>EN 1 IAL 

information is now in the public domain, fortunately very few details of technical significance 

or value can be found therein. Hints and even blunt statements about the great role played 

by COMINT in U.S. military, naval and air operations are found in books and articles published by U.S. Government officials and American officers, as well as by officers of the beaten 

Japanese, German, and Italian armed forces. In the interests of brevity, I will cite only a 

few examples. 6 

As regards disclosures by U.S. Government officials and officers, I can begin with those of 

the late Mr. Cordell Hull, who was Secretary of State at the time of the Pearl Harbor attack. 

In his memoirs are many references (over a dozen) to the contents of intercepted and solved 

Japanese Foreign Office messages. 7 The late Mr. Henry L. Stimson, Secretary of War at that 

time, makes clear references in his autobiography to COMINT successes and our failure to use 

them prior to the attack. 8 Dr. Herbert Feis, who was Mr. Hull's adviser on international 

economic affairs from 1937 to 1943, and from 1944 to 1946 was Mr. Stimson's Special Consultant, has a good deal to say about the role played by "Magic" in a book written as a member 

of the Institute for Advanced Study, at Princeton.' Admiral Kimmel, one of the two commanders in Hawaii at the time of the attack, in defending himself in his book, cites many 

"Magic" messages. 10 And Major General Sherman Miles, head of G-2 at the time of the 

attack, has much to say about "Magic" in an article published in 1948. 11 As regards disclosures by former enemy officers, the following are of particular interest because they concern 

the Battle of Midway, which is considered the one that turned the tide of war in the Pacific 

from a possible Japanese victory to one of ignominious defeat: 

"If Admiral Yamamoto and his staff were vaguely disturbed by the persistent bad weather and 

by lack of information concerning the doings of the enemy, they would have been truly dismayed 

had they known the actual enemy situation. Post-war American accounts make it clear that 

the United States Pacific Fleet knew of the Japanese plan to invade Midway even before our 

forces had sortied from home waters. As a result of some amazing achievements by American 

intelligence, the enemy had succeeded in breaking the principal code then in use by the Japanese 

Navy. In this way the enemy was able to learn of our intentions almost as quickly as we had 

determined them ourselves." 

"The distinguished American Naval historian, Professor Samuel E. Morison, characterized the 

victory of United States forces at Midway as "a victory of intelligence." In this judgment the 

author fully concurs, for it is beyond the slightest possibility of doubt that the advance discovery of the Japanese plan to attack was the foremost single and immediate cause of Japan's defeat. Viewed from the Japanese side, this success of the enemy's intelligence translates itself 

into a failure on our part-a failure to take adequate precautions for guarding the secrecy of 

our plans. Had the secret of our intent to invade Midway been concealed with the same thoroughness as the plan to attack Pearl Harbor, the outcome of this battle might well have been 

different. But it was a victory of American intelligence in a much broader sense than just this. 

Equally as important as the positive achievements of the enemy's intelligence on this occasion 

was the negatively bad and ineffective functioning of Japanese intelligence." 11 

& A good bibliographical survey of items concerning the attack up to the year 1955 will be found in the following: Morton, Louis. "Pearl Harbor in Perspective," U.S. Naval Institute Proceedings, Vol. 81, No. 4, Whole 

No. 626, April 1955, pp. 461-8. 

7 The Memoirs of Cordell Hull, New York: The MacMillan Co., 1948, Vol. II, pp. 998, 1013, 1035, 1055, 

1056-7, 1060, 1063, 1068, 1074, 1077, 1087, 1092, 1095, 1096, 1099-1100. 

s Stimson, Henry L., and McGeorge Bundy, On Active Seruice in Peace and War, Harper & Brothers, 

New York 1947, pp. 391-4, 454-5. 

o Feis, Herbert, The Road to Pearl Harbor, Princeton: The Princeton University Press, 1950, p. vii, and 

pp. 219-340, Passim. (See index under "Magic" on p. 350). 10 Kimmel, Husband E., Admiral Kimmel's S'tory, Henry Regnery Co., Chicago: 1954. 11 Miles, Sherman, "Pearl Harbor in Retrospect," The Atlantic Monthly, Vol. 182, No. 1, July 1948, pp. 65-

72. 

n Midway, The Battle that Doomed Japan: The Japanese Nauy's Story, by Matsuo Fuchida and Matasake 

Okumiya, U.S. Naval Institute Publication, Annapolis, 1955, pp. 131, and 232. Admiral Morison actually 

wrote: "Midway was a victory of intelligence bravely and wisely applied." See Vol. IV of his His'tory of 

CON'Plf>EN"i:'IAL 134 
REF ID:A63860 

It is the second extract above which is of special interest to us at the moment, and, in particular, the portion which refers to "the negatively bad and ineffective functioning of Japanese 

intelligence." The author is, I think, a bit too severe on the Japanese intelligence organization. I say this because their cryptanalysts were up against much more sophisticated cryptosystems than they dreamt of, or were qualified to solve. In fact, even if they had been extremely adept in cryptanalysis it would have been of no avail -U.S. high-level communications were protected by cryptosystems of very great security. 

This brings us to a phase of cryptology which is of highest importance-the phase which 

deals with communications security, or COMSEC, and I shall confine myself largely to its 

development and historical background in our Armed Forces. The background is a very 

broad one because it should include the background of the developments of each of the three 

components of COMSEC, uiz, (1) cryptosecurity, (2) transmission security, and (3) physical 

security of cryptomaterials. But since time is limited and because I think you would be more 

interested in the phases pertaining to cryptosecurity, I will omit further references to the other 

two components or to the history of their development. And even in limiting the data to 

cryptosecurity, I will have opportunity only to give some of the highlights of the development 

of the items that comprise our present cryptomaterials, omitting comments on the history of 

the development and improvement of our techniques, procedures and practices, all of which 

are extremely important. 

I shall begin the story with a definition which you will find in any good English dictionary, 

a definition of the word "accident." You will get the point of what may seem to you right 

now to be merely another of my frequent digressions from the main theme, but if it be a digression I think you will nevertheless find it of interest. The word "accident" in Webster's Unabridged Dictionary is defined as follows: 

1. Literally, a befalling; 

a. An event that takes place without one's foresight or expectation; an undesigned, sudden, 

and unexpected event. 

b. Hence, often, an undesigned and unforeseen occurence of an afDictive or unfortunate character; a mishap resulting in injury to a person or damage to a thing; a casualty; as, to 

die by an accident. 

There are further definitions of the word but what I've given is sufficient for our purposes. 

But why define the word? What has it to do with COMSEC? 

During our participation in World War II, the President of the United States, accompanied 

by many of his highest-level military, naval and civilian assistants, journeyed several times 

half-way around the world. He and they journeyed in safety-neither he nor they met with an 

"accident." Here's a picture taken at the Casablanca Conference in January 1943 (Fig. 103). 

Imagine the disaster it would have been if the plane carrying this distinguished group had been 

shot down and lost in the Atlantic or the Mediterranean. On the other hand, in April 1943, 

Admiral Isoroku Yamamoto, Commander-in-Chief of the Combined Fleet of the Japanese 

Imperial Navy started out on what was to be just an ordinary inspection trip but turned out 

to be a one-way trip for him. Here's a good picture of the Admiral (Fig. 104), who was the 

architect of the attack on Pearl Harbor. His death was announced in an official Japanese 

Navy communique stating that the Admiral "had met a glorious end while directing operations 

in a naval engagement against superior enemy forces." But we know that this was simply 

not true; Admiral Yamamoto "met with an accident." Some bright person-I think it was 

U.S. Navy Operations in the Pacific: _"Co~ Sea, Midway and Submarine Actions, May-August 1942." Little, 

Brown, New York: 1944, page 185. It is interesting to note that Adm. Morison, in an article entitled 

"Lessons of Pearl Harbor" published in the Saturday Evening Post, Oct. 28, 1961, concludes, "It was the 

setup at Washington and at Pearl, not individual stupidity, which confused what was going on. No one 

person knew the intelligence picture; no one person was responsible for the defense of Pearl Harbor; too many 

people assumed that others were taking precautions that they failed to take." 

135 
80NflBEN't'l2\L 

REF ID:A63860 

Figure 103. 

Figure 104. 

136 
REF ID:A63860 

the late Jimmy Walker, when Mayor of New York City-has said that "accidents don't just 

happen-they are brought about." Jimmy Walker's comment was true in this case at least: 

Achniral Yamamoto did not die by accident; he died because our Navy knew the schedule of 

his trip down to the very last detail so that it was possible to set up an am.bush with high 

degree of success. Here is the story as told in an interesting manner by Fleet Admiral William F. Halsey, U.S.N., in his book entitled Admiral Halsey's Story. 18 

"I returned to Noumea in time to sit in on an operation that was smaller but extremely gratifying. The Navy's code experts had hit a jackpot; they had discovered that Admiral Isoroku 

Yamamoto, the Commander-in-Chief of the Imperial Japanese Navy, was about to visit the Solomons. In fact, he was due to arrive at Ballale Island, just south of Bougainville, precisely at 

0945 on April 18. Yamamoto, who had conceived and proposed the Pearl Harbor attack, had 

also been widely quoted as saying that he was "looking forward to dictating peace in the White 

House at Washington." I believe that this statement was subsequently proved a canard, but 

we accepted its authenticity then, and it was an additional reason for his being No. 3 on my 

private list of public enemies, closely trailing Hirohito and Tojo. 

Eighteen P-38's of the Army's 339th Fighter Squadron, based at Henderson Field, were assigned to make the interception over Buin, 35 miles short of Ballale. Y amamoto's plane, a 

Betty, accompanied by another Betty and covered by six Zekes, hove in sight exactly on schedule, and Lt. Col. Thomas G. Lamphier, Jr., dove on it and shot it down in flames. The other 

Betty was also shot down for good measure, plus one of the Zekes.. We bottled up the story, 

of course. One obvious reason was that we didn't want the Japs to know that we had broken 

their code ... Unfortunately, somebody took the story to Australia, whence it leaked into the 

papers, and no doubt eventually into Japan ... But the Japs evidently did not realize the implication any more than did the tattletale; we continued to break their codes." 

But lest you get the impression that enemy intelligence agencies had no success at all with 

secret communications of U.S. Armed Forces, let me tell you that they did have some success and in certain instances, very significant success. There is not time to go into this somewhat disillusioning statement, but I can say that as a general rule the successes were attributable not to technical weakness in U.S. cryptosystems but to their improper use in the case 

of certain low-level ones, by unskilled, and improperly or insufficiently trained cryptographic 

clerks. I may as well tell you right now that this weakness in cryptocommunications has 

been true for a great many years, for centuries as a matter of fact, because as long ago as the 

year 1605 Francis Bacon, who wrote the first treatise in English on the subject of cryptology, 

made the following comment: 14 

"This Arte of Cypheringe, hath for Relative, an Art of Discypheringe; by supposition unprofitable; but, as things, are of great use. For suppose that Cyphars were well managed, there bee 

Multitudes of them which exclude the Discypherer. But in regards of the rawnesse and unskillfulness of the handes, through which they passe, the greatest Matters, are many times carryed in the weakest Cyphars." 

When electrical, particularly radio, transmission entered into the picture, additional hazards 

to communication security had to be taken into account, but many commanders failed to 

realize how much valuable intelligence can be obtained merely from a study of the procedures 

used in the transmission of messages as well as from a study of the direction and flow of radio 

traffic, the call signs of the transmitting and receiving stations, etc., all without solving the 

communications even if they were in cryptic form. Following are two paragraphs extracted 

from a document entitled Gennan Operational lnt;elligence, published in April 1946 by the 

German Military Document Section, a Combined British, Canadian, and U.S. Staff: 

"Signal intelligence (i.e., communication intelligence or COMINT) was a chief source of information in the German Army. In the eastern theater, where there was offensive warfare 

ia Admiral Halsey's Story. McGraw-Hill, New York, 1947, pp. 155-157. 

u The Two Bookes of the proficience and adun.ncement of Leaming, London, 1605, p. 61. This book is commonly known as The Aduancement of Leaming. Some 18 years later Bacon saw no reason to change his comment in his De Augmentis Scientiarum, London 1623. In fact, he strengthened it by making it read: " ..• but 

the rawnesse and unskillfulnesse of Secretaries, and Clarks, in the Courts of Princes, is such that many times 

the greatest matters are committed to futile and weake Cyphers." (Gilbert Wats' translation, 1640, p. 270.) 

137 
REF ID:A63860 

CONflBHN't'IAL 

primarily, the signal intelligence service was well-organized with well-defined purposes, efficient 

personnel, and adequate equipment. In the course of the campaign, it was reorganized to exploit to the fullest the success already experienced, and, by 1943, there existed a complete and 

smoothly functioning machine sufficient to meet all demands." (p. 8) 

"Most of their signal intercept success came from low-echelon traffic. Armored and artillery 

radio nets passing operational traffic were followed closely and were one of the chief sources of 

signal intelligence. Artillery radio nets were given first coverage priority. Apart from messages intercepted in code or in clear, signal procedure, peculiarities of transmitting, and characteristics of Allied radio operators provided enormous assistance in helping to evaluate signal information. The Germans noticed that call signs were often the same for a unit over long periods and that even frequencies remained unchanged for weeks at a time." (p. 8) 

A great many examples of intercepted messages of tactical content are cited in the aforementioned document, which is replete with information of deep interest, although the document was originally issued with the lowest security classification then in use (U.S. "Restricted"; 

British-Canadian "FOR OFFICIAL USE ONLY"). I wish there were time to quote at 

greater length from this useful brochure. 

Coming directly now to the history of the development of our cryptomaterials themselves, 

I hardly need reiterate what was pointed out in previous lectures as to the profound effect of 

the advances in the science and art of electrical communications in the 20th Century. Those 

advances had a direct effect upon military communications and an indirect effect upon military 

cryptology. Hand-operated ciphers and, of course, codebooks became almost obsolete because 

the need for greater and greater speed of cryptographic operations became obvious in order to 

match as much as possible the very great increase in the speed of communications brought 

about by inventions and improvements in electric wire and radiotelegraphy. The need for 

cryptographic apparatus and machines thus very soon became quite obvious, but it took quite 

some time to satisfy that need in a manner that could be considered to give adequate security 

for military communications. 

The history of the invention and development of cryptographic devices, machines and 

associated apparatus and material is long and interesting. Let us begin with a resume of the 

earliest items of importance in that history. 

Until the advent of electronic cipher machines most cryptographic apparatus and devices 

were built upon or around concentric circular rotating members such as cipher wheels, cipher 

disks, etc. A very early, perhaps the earliest picture of such a device appears in a treatise by 

an Italian cryptologist named Alberti, whose Trattati in Cifra was written in Rome about 

1470. It is the oldest tract on cryptography the world now possesses. Here's a photo of 

Alberti's disk (Fig. 105), but I won't take the time to explain it except to say that the digits 

1, 2, 3, 4 were used to encipher code groups and to call your attention to the fact that the 

letters of the cipher or revolving alphabet were in mixed order. In Porta's book, :first published 

in 1563 in Naples, there appear several cipher disks; in the copy which was given me as a gift 

by Colonel Fabyan, they are still in working condition. Here is a picture of one of them 

(Fig. 106). In this version the device uses symbols as cipher characters. And apparently 

nobody thought up anything much better for a long, long time. It seems, in fact, that not 

only did no one think up anything new or even some improvements on the original Alberti or 

Porta disks but those who did any thinking at all on the subject merely "invented" or "reinvented" the same thing again, and that happened repeatedly in successive generations. 

For instance, in Lecture No. IV of this series you were shown a picture of the cipher disk "invented" by Major Albert Myer, the :first Chief Signal Officer of the U.S. Army, who obtained 

a patent on his invention in 1865. Here's a picture of the patented disk (Fig. 107) and the 

explanation of the invention (Fig. 108). You may also remember that signalmen of the Confederate Signal Corps mechanized the old Vigenere Square and put it out in the form of a cylinder (see Figs. 65 and 66 of Lecture No. IV). The cipher disk used by the Signal Corps of 

the U.S. Army during the decade 1910 to 1920, that is, during the period including our par138 
REF ID:A63860 

Figure 105. Figure 106. 

ticipation as a belligerent in World War I, was nothing but a white celluloid variation of the 

original Alberti parchment disk of the vintage of 1470 (except that it was even simpler than 

its progenitor, because in the latter the cipher alphabets produced were mixed alphabets whereas, in the Signal Corps disk, the cipher alphabets are simple reversed standard sequences (Fig. 

109). We all know that it generally takes a pretty long time to get a patent through the 

U.S. Patent Office, but the ancient device was patented in 1924 by S. H. Huntington (Fig. 

110): here you can see a great improvement over the Signal Corps version-a blank is added to both sequences so that the space between words could be enciphered. Indication of 

word space, as you have learned, is a fatal weakness if seen in the cipher text; in the Huntington 

device the spaces between words would be enciphered but the cipher text would have space 

signs, although they would not correspond to the actual spaces between words in the plain 

text. In the Huntington device, the space signs in the cipher text would be a bit misleading 

but not to an experienced cryptanalyst, who would soon realize that they do not actually represent "word space" in the plain text. 

It is interesting to note that in 1936, during the days when the German National Socialists 

were banned as an organization in Austria, the Nazis used this variation of the old disk-it had 

10 digits on both the outer and the inner sequences for enciphering digits (Fig. 111). 

The first significant improvement on the old cipher disk was that made by Sir Charles Wheatstone, in 1867, when he invented a cipher device which he called The Cryptograph. He described it in a volume entitled The Scientific Papers of Sir Charles Wheatstone, published in 

1879 by the Physical Society of London. Here is a picture of the Wheatstone device in my 

private collection (Fig. 112). What Sir Charles did was to make the outer circle of letters 

(for the plain text) comprise the 26 letters of the alphabet, plus one additional character to 

represent "space." The inner circle, for cipher equivalents, contains only the 26 letters of the 

alphabet, and these can be disarranged in a mixed sequence. Two hands, like the hour and 

minute hands of a clock, were provided and they are under control of a differential gear mechanism, so that when the long or "minute hand" is advanced to make a complete circuit of the 

letters on the outer circle the short or ''hour hand" advances one space or segment on the 

inner circle. In Fig. 112, for example, the plaintext letter G is represented by the cipher letter 

A, that is, GP = A.. If the long hand is now advanced in a clockwise direction for one revolution, GP will be represented no longer by A. but by G., the letter immediately to the right 

of A. on the inner circle. In encipherment the long hand is always moved in the same direction (clockwise, for example), and its aperture is placed successively over the letters on the 

139 CONflf>HN'ffA:L 
REF ID:A63860 

_;fJ~11; 

~g~/y )}.7111;. 

JJ/f.rg.1..to. Au.nkli.1%r./.4/d6"i.. 

- -- -- c::: -- ------ -- -=- - - -- ---- - -- :- -----::. - -- • 

Figure 107. 

CONJ!IDEN'f'IAL 140 
REF ID:A63860 

UNITED STATES PATENT OFFICE. 

ALBERT J, ?tlYER, OF WASHINGTON, DIST.RIOT OF COLUMBIA. 

IMPROVEMENT IN SIGNALS. 

Spcc16cat1on forming part of Letters Patent No. 110,NG, dated November U, 11!65. 

To all 1r11011i it t11ay co11cern: 

Be it known tbo.t I, ALBERT J. MYER, of 

Washington city!. District of Colombia, have 

invcntetl a new Diode of Commnnicating by 

Signals; mul I do hereby declare that the followmg is a foll, clear, autl exact 1lescription thereof, reference being bad to the accompanying drawings, making a part of this specifica- tion, in whichFignrc 1 is a front Yiew of t\\O llisks having 

certain characters. npon tbem to be nsed i11 

communicating by signals. l~1g. 2 is a diamet1ical section through the 1l1sks, shO\\ ing the manner of nttacbiug tbe1n together. 

The object of this ill\ 1•nt1on 1s to nftiml means "bereby persons within signnl tlistnnceof each 

othe1· c11n commm1icate intelligibly by certain 

movement." of l:lags or other object11, mul a sys- tematic 11rrm1gement ot letter11 amt nuuu•rals or other char.1ct1•rs 1111on mo\·ahleaud 11tat1011-

1uy tlisks, without the 11ossib11ity of luwiug 

their messages detected by otber111. 

To 1•111\blt.• othe1·11 sk1Ile1l in the art to nnderKtaml 1nyim·ent1011l\V11l1le11e11be myimpro\·ed 

metbo1I of signaling. 

In the at companying tlr '"' 111g11, A reprclll'nts 

I\ disk ha\ iug 11rintetl or engrn\"l'd upon it in 

auy sequeuce cel'tain llg11rct1 or cbarncter11, 

winch i11d1catesignal11 to be made or cbaracters or \VOrds to be written. B is a 11111aller 1hsk 

hn\'iug upon 1t tire letters of an al11habl't iu 

any 1lesire11 sequence, which 1t may be tlesiretl 

t11 refer to in signal mg. These two disks 11re 

(li\"otetl togetlrerceutralh by111e111111 of aclaro1l· 

sel'ew, on looseuiugwhich the11111allerdisk may be turnetl in eitlrer 1lirection, 110 n11 to 111iug 

ddlil1·1'n t ltlttei·s opposite to the 11 umerals, after 

\\hieb, by tightenmg tire screw a, the 1lisks 

\VIII be rigidly eonnectetl together. 

Each person giving 11n11 receh"mg signals 

should be pro\•idetl with oue of tlaebe de\·1ces, 

amt there should be a. 11reconeerte1l understanding between such perso1111 fo1· mo,·iug the 

disk B amt causing d1fterent signal combiua· 

tious to stand at dilfereut times tor ditterent 

ll'tters 01· messages, for the pur11ose of conceal· 

iug the meaning of the signals. The mode of sigualiug is as follows: Suppose two persons \Vithin signal distance or each other should desire to communicate the 

word "are," aud by preconeerted signals ha\'e 

both adjusted their disks so that the letter A 

shall be opposite to the number 11. Now, to 

spell the word "are" the signalsdesignatedby theeombination "11" for"A"aremade1 and this 

will indicate to the observer the letter "A." 

Then there should be made the signal indicated 

by the figures•18111"or"R,"and this would indicate to the observer this letter. The signal 

orsignals iudieatingtheletter"E," which are "1181 n on the disk, conclude the word are. It may be desirable for purposes of couecal· 

meut that the word "are," though often occur- ring, should not dgain be indicated in the same communication by the same signals. In this case let it be untler11tood 'by 11reconeert tlrat 

npon any given signal, s11clr mi tbe d1·op11i11g 

of a flag or some 11eeulhll' wa \'e uf a fla)!', the 

s111a1ler 1lisk, or that whit·h has u11on 1t the 

letters of f,he alplmhet, i11 lo he mo\"etl n11on 

the larg«i"st disk, ur tbut which haii 1111on it the 

mnnerals, turning lo the riitht baud, sal, the 

1h11tauce ot' l'onr 1111aces, marked upon the disk. 

Now, without oo~satiou of signaling, both per1101111, the transmitter aml the l"l'Cf'l\"er, would 

n1•on tbis signal 1·ach t10 cbauge the 11os1tion 

of the 1hsks th11t in again signaling the wo1d 

"are" "A"wonldstaud oppo11111etoand bedf'11-

ignated by the combmatrou "1881" "R" \VOuhl 

be de11iguatecl by the cnmbiuation '' ll88,''aud 

"E" by "1881." 'l'hl• h•tter11 "A U B" or the 

word ''are" thus signaletl woulll in 110 Wa) re- semble the siune w01·d before seut. In th111 wa~· it cuu lie RO arranged by preeoncl•1·1111g 

that 110 word shall ap(lt'ar twice in the same man nor 111 the 1111111e nwssage. 

There may be se\ eral disks joinetl together, ha\•mg \"anous figures and ch11ractt'1'l:I upon 

them, and by 11reco11cert it may bti 11n1ler11too1l 

that in eertam me11sages some of them are to 

be used and not othe1s, or there may be mo1e 

than one row of lignre11 01· characters 1111 any 

ot the llisks aud the )lroeoncertt'll arrangl!meut 

for using may be ellangetl 111finitely, so that 

the uuiustl'nctetl cannot tliseover in what man- ner the 1Ii11k11 are to be 100\•etl or UKed. 

Ha,·ing thus 1IC11cribe1l my invention, what 

I claim as new, a111l desire to secure by Letter11 

Patent, i11-

1.'be \Vitltin-deserilletl 11ystem of signaling, 

which is controllell by means ot. letters, nu- merals, or other characters upon disks that a1'6 

put together in such manner that the relative 

positio11s of such characters can be changed at 

I1leasure, substantially as set forth. 

ALBERT J, MYER. 

Witnesses: 

R. T. 0..un>BELL1 E, SOJUP'BB, 

Figure 108. 

141 
REF ID:A63860 

C6NPIBEN'f'IA:L 

Figure 109 • Figure 110. 

• 

Figure 111. Figure 112. 

142 
REF ID:A63860 

outer circle according to the successive letters of the plaintext message, the cipher equivalents 

being recorded by hand to correspond with the letters to which the short hand points on each 

encipherment. In this way, identical letters of the plain text will be represented by different 

and varying letters in the cipher text, depending upon how many revolutions of the long hand 

intervene between the first and subsequent appearances of the same plaintext letter. Thus, 

wiU1 Lhe alphabeLs shown in Fig. 112, and wiLh Lhe iniLial seLLing GP = A., the word "refer-

" uld be ted. . her fi II REFERENCE . hich "twillb that ence wo represen m cip as o ows: XZZZBGQAM' m w 1 e seen 

repeated letters in the plain text are represented by different letters in the cipher text. Correspondents must naturally agree upon the mixed alphabet used in the inner circle and the 

initial positions of the two hands at the beginning of the encipherm.ent of a message. In decipherment, the operator moves the long hand again clockwise, until the hour hand points to 

the cipher letter in the plaintext letter which is seen through the aperture at the end of the long 

hand on the outer circle. Thus, in the case of the example given above the cipher letters 

XZAABGQAM will be found to represent the word REFERENCE. 

During World War I, some time in 1917, the British Army resuscitated Wheatstone's cryptograph and improved it both mechanically and cryptographically. Here's a picture of the 

device (Fig. 113), in which it will be seen that there are now no longer the "minute" and "hour" 

hands but a single hand with an opening or window that simultaneously discloses both the 

plain and the cipher letters. When the single hand is turned, the inner circle of segments, 

which are made of a substance upon which letters may be written in pencil or in ink is advanced eccentrically and against a similarly-made outer circle of segments. In this improvement on the original Wheatstone device both sequences of letters are now mixed sequences. 

Making the outer circle also a mixed sequence added a considerable degree of security to the 

cipher. When it was proposed that all the Allied armies use this device for field cryptocommunications and its security had been approved by British, French, and American cryptologists (both at GHQ-AEF and at Washington), an opportunity to agree or disagree with the 

assessment of these cryptologists was given me while still at Riverbank. I was able to show 

that the modified Wheatstone cryptograph was still insufficiently secure for military purposes, 

Figure 113. Figure 114. 

143 
REF ID:A63860 

and the devices, thousands of which had been manufactured and issued, were withdrawn. If 

you are interested in the method of solution, I used you will :find it in Riverbank Publication 

No. 20, entitled Several Machine Ciphers and Methods for their Solution (1918). A better 

method of solution was devised by me about 1923. 

Some years later, and almost by sheer good fortune, I learned that a cipher machine was in 

the museum of a small town in Connecticut named Hamden. I was interested and wrote to 

the curator of the museum, requesting that he lend the device for a short period to me as principal cryptanalyst of the War Department. Imagine my astonishment and pleasure when I 

unpacked the box upon its receipt and found a device, beautifully made and encased in a fine 

mahogany case, with its inventor's name, Decius Wadsworth, and the date, 1817, engraved on 

the face of the machine, which was nothing but another version of the Wheatstone Cryptograph. Here's a picture of it (Fig. 114). There are good reasons to believe that the model 

was made by Eli Whitney. Mechanically it was similar to the British modification, except 

that the outer sequence had 33 characters, the inner 26, so that the differential gear instead 

of operating on the ratio of 27 to 26 was now on the ratio 33 to 26. Thus, Colonel Decius 

Wadsworth, who was then the first Chief of Ordnance of the U.S. Army, had anticipated 

Wheatstone by over 60 years in this invention. He also anticipated the British Army cryptologists of World War I by a whole century in their modification of Wheatstone's original, because in the Wadsworth device, too, there was only one hand and both alphabets could be 

made mixed sequences. This is very clearly shown in Fig. 115 as regards the outer sequence, 

and I believe the inner one could also be disarranged, but the picture does not clearly show 

this to be the case, so that I am not sure as to this point. I returned the device a good many 

years ago, and it is now on display in the Eli Whitney Room of the New Haven Historical 

Society's Museum. 

The next device I bring to your attention is shown in Fig. 116, a device invented by a French 

Army reservist, Commandant Bazeries, who for some 10 years valiantly but unsuccessfully 

tried to get the French Army to adopt it. He included a description of his device, which he 

called his "Cryptographe Cylindrique" or "cylindrical cryptograph," in a book published in 

Figure 116. 

Figure 115. 

144 
• 

REF ID:A63860 

1901 in Paris. 16 He had, however, previously described his device in an article entitled "Cryptographe a 20 rondelles-alphabets (25 lettres par alphabet)," published in 1891. 16 In this 

device there is a central shaft on which can be mounted 20 numbered disks on the peripheries 

of which are differently mixed alphabets of 25 letters each. The disks can be assembled in 

some prearranged or key sequence on the shaft, from left to right, but they can be revolved 

thereon and then locked into position on the shaft by pushing in the locking disk at the extreme left. The :first 20 letters of the plain text of a message are :first aligned, as seen in Fig. 

116 (JE SUIS INDECHIFFRABLE = "I am indecipherable"); the disks are then locked into 

position so that the whole assemby can be turned; and as cipher text one may select any one 

of the other 24 rows of letters, which are recorded then by hand on paper. Then the next 20 

plaintext letters are aligned, one of the other 24 rows of letters selected and recorded, etc. To 

decipher a message, the disks having been assembled on the shaft in accordance with the prearranged or key sequence, one takes the :first 20 cipher letters, aligns and then locks them into 

position, and then turns the whole cylinder, searching for a row of letters which form intelligible text. There will be one and only one such row, and the plaintext letters are recorded. 

Then the next 20 letters of cipher are aligned, etc. 

Another French cryptologist, the Marquis de Viaris, soon showed how messages prepared 

by means of the Bazeries cylindrical cipher could be solved.17 Maybe that is why Bazeries 

wasn't too successful in his attempt to get the French Army to adopt his device. But in the 

U.S. there were apparently none who encountered either what Bazeries or de Viaris wrote on 

the subject. Capt. Parker Hitt, U.S. Army, whom I have mentioned in a previous lecture, in 

1915 invented a device based upon the Bazeries principle but not in the form of disks mounted 

upon a central shaft. Instead of disks, Hitt's device used sliding strips and here is a picture 

of his very :first model (Fig. 117), which he presented to me some time in 1923 or 1924. But 

I first learned about his device some time in 1917 while still at Riverbank and solved one 

challenge message put up by Mrs. Hitt, a Riverbank. guest for a day. In meeting the challenge successfully (which brought a box of chocolates for Mrs. Friedman from Mrs. Hitt) I 

didn't use anything like what I could or might have learned from de Viaris, because at that 

time I hadn't yet come across the de Viaris book. I solved the message by guessing the key 

Mrs. Hitt employed to arrange her strip alphabets. She wasn't wise to the quirks of inexperienced cryptographic clerks; she used RIVERBANK LABORATORIES as the key, just as I 

suspected she would. The device she brought with her was an improved model: the alphabets were on paper strips and the latter were glued to strips of wood, as seen in Fig. 118. 

Capt. Hitt brought his device to the attention of the then Major Mauborgne, whom I have 

also mentioned in a previous lecture and who was then on duty in the Office of the Chief Signal 

Officer in Washington. There is some question as to whether it was Hitt who first brought 

his device to Mauborgne's attention; Mauborgne later told me that he had independently 

conceived the invention and, moreover, had made a model using disks instead of strips. I 

have that model, a present from General Mauborgne many years later. It is made of very 

heavy brass disks on the peripheries of which he had engraved the letters of his own speciallydevised alphabets. In 1919, after my return to Riverbank. from my service in the AEF, 

Mauborgne sent Riverbank. the beginnings (the :first 25 letters) of a set of 25 messages enciphered by his device and alphabets. He also sent the same data to Major Yardley, in G-2. 

Nobody ever solved the messages, even after a good deal of work and even after Mauborgne 

told us that two consecutive words in one of the challenge messages were the words "are you." 

Many years later I found the reason for our complete lack of success, when I came across the 

plain texts of those messages in a dusty old :file in one of the rooms occupied in the old Munitions Building by the Office of Chief Signal Officer. Here is a picture of the beginnings of the 

:first six messages (Fig. 119). Mauborgne, when I chided him in the unfairness of his challenge 

11 Les Ckilfres secrets d6voilis. 11 Comp~ Rendus, Marseilles, Vol. XX pp. 160-165. 

n L'art de ckilfrer et de dkkilfrer les d6p8ckes seen~. Paris, 1893, p. 100. 

145 
REF ID:A63860 

x ~ J x H F C GD B .. K y p L 0 B u l x 5 ll 'f R 

UV K Z B' '1' D B~ c G p L w )! y l A 0 z v RHB 

A 0 ~ J R HS C G D B , JI y p L • 3 u J x Q, If '1' 

.I u I X s :rr '1' RB I' c G D L " JI y p A K z V K•H 

l A 0 3 T RH B IJ G D B ., c y p L • II Q, J x"' J Q 11: U I L 8 Iii T R A ., c 0 D v YI ),[ y p v K z V K ~ ''l' I A 0 r y B H 8 • u D B ., x ~ p L w B Q, rl x Q, ill b XU p L W )[ T i A 0 c 0 z v Y. JI y c G Jt z ,. r-'R T RA w Ji! y P H 0 J: u I B J x ~ J L D :B '!' J x 

t It F. S K y p L • )l u I A 0 • lt z 1t z ., c Q DZ 

» S K '1' R A • 11 y p Q, 0 K u l ~ J x ~ J 0 D B ~ C 

!': a R HS .I 'O p L 'I v Jt I A 0 H K z v K L ., C D 

JJ B 1 5 T I A 0 KY x Q, J .. u )I T J x Q, K y D F « C G D H 0 ll 'O l L z v K z A R H s z v p J. w 0 

DB , c u I A 0 I: J x " J x B 11 T R x .. II L F C G D r. 0 .I u l K z v K z T R H 8 I I • y p KY D B 1 Q, J I A 0 H J x Q, J B s II T R A .. K p P L W C G v K Z :I u JI T z v K c Q R H B K u p w .. J( y p B x Q, J X A R H s x Q, D B ., JI T I A 0 y 

y P L .. )( z V IC z v 8 )I T R v !I' c 0 D H 0 • U I L 

J " K y p J x lil J x T R H 8 'lli a D B I' c u I A•O K 

K: 1- L W lS z v K Z L s N T R A , c a D H 0 :a: U I 

q J x KY c G X ~ J J.t y R H 6 E u D B ,. ~ ? I 'A 0 

i K Z via.. D B 1 V K p L • K T I A 0 c 0 R H s l!I u 

'l Ii. J x ~ !I' c 0 D ~ w K y p H 0 .I u I B 8 N TR A 

z v !'. z v 0 DB F C y p L w l.t u I A 0 :I T R H 8 N 

ix~ J x 11 1 c G D D fi K y p L 0 B u I x s H 1' R 

u v K Z N T D B F c G l' L w • y I A 0 z v RH 8 

A 0 ~ J J.i HS c Q D '.B ., l: y p L w E u J x Q. l'f T 

D .I IJ I K s N•T RB p c G D L ., If. y J:I A K z V K H 

U I A 0 :z. T RH Si !t G D B I' c y p L w Ji!. ~ J x Q. J 

H 0 E U I L S N T•R A ,. c G D v ., ii y p v K z V K 

:ti T I A 0 K y R H'S n: u D B F x ~ p L w B ~ J x"' R H S :B u p L W NIT I A 0 c G z v r: )[ y c 0 K Z V 

6 ll T RA w lt y p H 0 ~ u I B J x Q. J L D B J':J x 

T 

B 

R H 6 N y P L WK u I A 0 :a: K z v K z p c OID z S N T R A Ti K y p ~ 0 JI: u I Q, J x Q. J 0 D B P C 

C Q R H 8 B up L W v K I A 0 H K z v K L • C 0 D 

D .ll p N T I A 0 Ky x Q. J .I u Ii T J x Q, u y D Bill' 

F C 0 D H 0 :& u I L z v K z A R H s z v p L w cla 

G D :& F C u I A 0 l!: J x Q. J x B N T R x ., )[ y pr~ L F C G D K 0 :s U I K z v J[ z T R H B N y p L: W ll K Y D B F Q, J I A 0 H J x Q. J B s N T R A ~ JI y p P L W c 0 v K Z :B u N 'l' z v K c G R H 8 JC 'O P1Ii:W • )[ y I' l! x Q. J X A R H 8 x Q. D B F N '1' I A o:!if,y y p L w )( z VK z v 8 N T R v F c G D B 0 :s u l J. J fl )( y p J I Q. J x T R H 8 H a D B 1' c u I A' O!JC 

IC Z P L W B z v K Z L 8 JI T R A ll' c 0 D H 0 :S. tl'I I Q. J x J( y c G X Q. J u •Y R H B B u D B p z: T I A 0 

v iC z VL D :B J' V K p L " N T I A 0 c G R H S B U 

x ~ J x~ i' C G D Q. YI ll y p n 0 .&: u I B $ x T R A 

! \' K z v 0 D :B P' c IY p L .. JI u I A 0 .B: T R H B N 

' 0 0 u 0 u 010 0 l l 1 l l 1 ~ l l l. :i! 2. :i! ;t l ;,z· ii: 

l 213 4 5' 6 7 8 9 0 l 2 13 4 5 7 8 9 0 l 2 3 ~ 5 . • -. 

Figure 117. 

146 
REF ID:A63860 

messages, told me that he had not prepared them himself-he had an underling (Major Fowler 

was his name, I still remember it!) prepare them. In our struggles to solve the challenge messages we had assumed that they would contain the usual sorts of words found as initial words 

of military messages. It was the complete failure by Riverbank and G-2 to solve the challenge messages that induced Mauborgne to go ahead with the development of his device. It 

culminated in what became known as Cipher Device, Type M-94. Here is a picture of it 

(Fig. 120). That device was standardized and used for at least 10 years in the U.S. by the 

Army, the Navy, the Marine Corps, the Coast Guard, the Intelligence Agencies of the Treasury 

Department, and perhaps by other agencies. 

In 1922, a wartime colleague, the late Capt. John M. Manly (Professor and Head of the Department of English at the University of Chicago) brought to my attention a photostat of 

two pages of a holographic manuscript in the large collection of Jefferson Papers in the Library 

of Congress. It described his invention entitled "The Wheel Cypher," and here is a picture 

of the second page (Fig. 121) showing Jefferson's basis for calculating the number of permuta-

"ri~in•I VoJel of Cipher :Jey!ce 

11-138-.~ 

yado by Captain Fark•r hi tL • I n1' • 

Figure 118. 

147 

! . : 
REF ID:A63860 

GONPIB:eN'f'IAL 

Figure 119. 

tions afforded by the set of 36 wheels of his device. He didn't attempt to make the multiplication; he didn't have an electronic digital computer- for the total number is astronomical 

in size. Jefferson anticipated Bazeries by over a century, and the Hitt-Mauborgne combination by almost a century and a half. 

Figure 120. 

It soon became apparent to both Army and Navy cryptologists that a great increase in 

cryptosecurity would be obtained if the alphabets of the M-94 device could be made variant 

instead of invariant. There began efforts in both services to develop a practical instrument 

based upon this principle. I won't take time to show all these developments but only the 

:final form of the one adopted by the Army, Strip Cipher Device Type, M-138-A (Fig. 122). 

This form used an aluminum base into which channels with overhanging edges were cut to 

hold cardboard strips of alphabets which could be slid easily within the channels. It may be 

of interest to you to learn that after l had given up in my attempts to find a firm which would 

or could make such aluminum grooved devices in quantity, Mrs. Friedman, by womanly wiles 

and cajolery on behalf of her own group in the U.S. Coast Guard, succeeded in inducing or 

enticing one firm to make them for her. And that's how the first models of strip cipher devices 

made of aluminum by the extrusion process came about, and how the U.S. Army, by administrative cooperation on an inter-Service level and technical cooperation on a marital level, 

found it practical to develop and produce in quantity its Strip Cipher Device, Type M-138-A. 

This was used from 1935to1941or1942 by the Army, the Navy, the Marine Corps, the Coast 

148 
• 

REF ID:A63860 

C6N.FfB:BN'f'l1H:i 

Guard, et al, including the Treasury and State Departments. It was used as a back-up system 

even after the Armed Services as well as the Department of State began employing much 

better and more sophisticated cipher machines of high speed and security. 

Figure 121. 

Thus far we have been dealing with cipher devices of the so-called "hand-operated" type. 

None of them can readily be considered as being "machines," that is, apparatus employing 

mechanically driven members upon which alphabetic sequences can be mounted so that constantly changing sequences of cipher alphabets are produced. We come now to types of apparatus which can be called machines, and one such machine is shown in Fig. 122. It is called 

the Kryha machine, after the name of its German inventor, who unfortunately committed 

suicide a few years ago, perhaps because the last model of his improved machine failed to impress professional cryptologists. The Kryha has a fixed semicircle of letters against which is 

juxtaposed a rotatable circle of letters. Both sequences of lett.ers can be made mixed alphabets (the segments are removable and interchangeable on each sequence). The handle at the 

right serves to wind a rather powerful steel clock spring which drives the rotatable platform 

on which the letters of the inner circle are mounted. In Fig. 124 can be seen something of 

149 
c0NF1DEN'11AL 

REF ID:A63860 

__,__ 

.. -----:-:--

_______ 

. ,, ..... 

---.. 

.... 

-... 

"!":" 

--- - -

. --- - -------

. :;- ,; 

'------

! - -" ,; .. --;- 4- - - -

..... ..!~ "W-- --~'1~- - .. __ -- --- - - -_ ___.. _____ -- ---- - ........ 

.... ----.---.-... ---.-- --- -

=-- - .. _ 16 -.... =.L.. -~------­ . ' .-, -; .. -----:- ~ - - c.- ... _ ------- - --

Figure 122. 

the inner mechanism. The large wheel at the right has segments which are open or closed, 

depending upon the "setting" or key. This wheel controls the angular displacement or "stepping" of the circular rotatable platform. The initial juxtaposition of the inner or movable 

alphabet against the outer or :fixed one, as well as the compostion of these alphabets, is governed 

by some key or other prearrangement. The cipher equivalents must be recorded by hand. 

After each encipherment, the button you saw in the center of the panel in Fig. 123 is pushed 

down, the inner wheel is advanced 1, 2, 3, 4 ... steps, depending on the key, and the next 

letter is enciphered, etc. The pictures I've shown you apply to the latest model of the Kryha; 

as regards the first model, which came on the market sometime in the 1920's, a German mathematician produced an impressive brochure showing how many different permutations and 

combinations the machine afforded. Here's a picture of a couple of pages of his dissertation, 

(Fig. 125) but even in those days professional cryptanalysts were not too impressed by calculations of this sort. With modern electronic computers such calculations have become of even 

less significance. 

Let us now proceed with some more complex and more secure machines. In this next illustration (Fig. 126) you see a machine which represents a rather marked improvement by a 

Swedish cryptographic firm upon the ones shown thus far. It is a mechanico-electrical machine designated as Cryptographe B-21. Here for the :first time you see a cryptographic machine provided with a keyboard similar to that on an ordinary typewriter. Depressing a key 

150 
.. 

REF ID:A63860 

Figure 123. 

on this keyboard causes a lamp to light under one of the letters on the indicating bank above 

the keyboard. At the top of this machine can be seen four wheels in front of two rear wheels. 

The four front wheels are the rotating elements which drive the two rear wheels; the latter are 

electrical commutators that serve as connection-changers to change the circuits between the 

keys of the keyboard and the lamps of the indicating board. There isn't time to discuss in 

detail the internal works which control the rotating elements and ciphering wheels, of which 

you'll see a glimpse later, but I must show you the next step in the improvement of such apparatus, which made it possible to eliminate the really tedious job of recording, by hand on 

paper, the results of operation. This was done by means of associating a typewriter with the 

crypto-component. Here is a picture (Fig. 127) which shows the assembly-the B-21 connected to a Remington electric typewriter, modified to be actuated by impulses from the 

cryptomachine. Of course, it was natural that the next step would be to make the recording 

mechanism an integral part of the cryptomachine. This you can see in the next picture (Fig. 

128a), in which the four rotating members referred to in connection with Fig. 126 and which 

control the two commutators also mentioned in connection with that :figure are seen. The 

slide-bar mechanism in Fig. 128b, at the right, is called the "cage" or "barrel" and controls 

the displacements of the printing wheel, causing the proper letter to be printed upon the moving tape seen at the front of the machine. 

Now we come to some very important new types of electric cipher machines :first conceived 

and developed in Europe but very soon thereafter, and probably independently, also in the 

U.S. In the crypto-component of these machines, the electrical paths between the elements 

representing the plaint.ext characters and those representing their cipher equivalents are constantly varied by multiple connection-changers with the crypto-component. In early Euro151 C~DRN'flA1' 
REF ID:A63860 

CON.FIBEN'i:'IAL 

Figure 124 • 

..... f"(~)11• ... 0(mol.JI) 

(ir,-.~lf1111i1P 

nr e!De l"rlmuJil .P lR ill• d• J!er•ahc•e Sat.a1 

11(.),--1)1110(-1.P). 

X••··· ••r ... a.1 tec••IHk •II• CkarfrlerrliH 'Hit. P - I bq P - .P..,Llchn• her1Hiellt wer4ea lll••H, 

• -* m. aam hanal&&-. 1111• P uUtlba;le G-a.lil. .U.. KamlaaaliN'llf-l)IJ..z;.-ir•c..V-l)'J,:;r-(~}lP 

f L l!lm llulmallalll Jt • mu I-' pp11m1. 

1 ... ••••Ads••• ..Ubiht. Wanlt., 4all aa tier l'ndl 11.- ,i., r.t.ldi.niell Vmfq i1el Clilll'ntl'l"&IW. 1111111111 Gdll 

.._ ,._.... u. Jladmabahl aer Ziii•• lutlkgt JI. - 171. v. a.... Jlu.lmalahl wft'l1en 11111 lbedllllll.- Cartpr.;k. Die 

-, ID •tnelaa4i Aulp'ba laatet 

W'1e oft lllt 1aa.k e1aeZalr.l I 1n.P Ba•aaniea, lie 

0.1, N-1 •H• lr.laaen, Hrglldua•)P Dabe1 .a•ln 'D'm1tellea1H all 'IHHl1ail1a. Bella llaH Zahl C(l, . P,.!I). w1• 1HI lit ...... r1Jl,.P,:tn -.~u C(I, p .,, Jn 

Jl'!U'(,Jf-1), • --.w & ~ ofl'l!:llbu 11Wr.t1 a.a 

•llllllJl'laenukc--. FIRl>P(..Y-1) ma10-o .... 

... War1r:lll..eaC-6•:.Je...._....a.blltmmia. :II 

(1+.s+.z"+ +.-1"-l:Crl - n--~Taa .... "bt: ... , •• ·-· oft.-eliJ:lkaa..e - l' ................. 0,1,t. lr-lillatlllllll. lllt. ... 

1111.U.llakeS.• 

(l-"7'(1-.,....-.!.<-IJ"(~ ... ,.!.('+;-•) ... 

.... .. c-(P+ :-')-( f)(P+::;-1)+(:)("+::::-IJ-+ Ml ............... &ult.·-~ - ... •hnlbn 

-(P,t•1•1-m(P+~:f-•1+m1P+>;~f-•1-+ 

. J"t.I(, .P,JV) -.!,.O~, P,ll) 

JI •WW.. bm-.U. w1r ._ Sat&. i!ll ::E t! ebllC' Patuuini!ie 

l: Cll iler Ko.mn.t Tiii!. 'II' la. a.. :Eat.wlddug ·-· Tm 

y!.:Ec.-

r-(•;')-m(•+;-")+mt•+~-·")-+ 

w.••Mll.alllmclL Dll wlil ....,e. ftlr .lfS:P(lf-1) il•Wl 1r ...._~ 

..a,t~Ur 

Bolz I 

("t"l-m1•+:-"J+m1•+~-·"l-+ _,... flllo.ll~.P(Jf-1). 

.&.. -..i-. o.-11 Mp .ti' •ta• ... >.P(Jl'-1)111 

('~~ )-(i)('+~:f-')~t:Jf+~:_'f- )-+ - a 

Will-. nlclil wl1 t..Ji. llr • baaH-• l'•I• ,...,.., 

............. Flll1 ....... llBl1mi Rlr.U. P-.P-l m.I'., 1111r.t.-..W.ut••'l'li1Lublt.-P•aclllll. !'lrP -1ar1111t;-ila.lf:>N-l1 -Wl~-11(..._llf.illir ,. 

Figure 125. 

OON.FIBHN'i'IA:L 152 
, 

REF ID:A63860 

Figure 126. 

pean models of this type of machine the connection-changers consisted of a frame upon which 

insulated wires were mounted to connect in an arbitrary manner a series of contacts on one 

side of the frame to a similar number of contacts on the other side of the frame. This frame 

was slid between two :fixed contact-bearing members, one on each side of the frame. By sliding 

the frame between the two fixed members, the paths between the opposite contacts on the 

latter could be varied as a whole set with a single movement of the sliding frame. A connectionchanger of this sort is shown in schematic form in Fig. 129a, where the sliding member 10, 

slides between :fixed members 11 and 12, thus changing the electrical paths between the keyboard and the printing mechanism.. The connection-changer 10 is moved to the left or right 

1,2,3, . . . positions, as determined by a cam mechanism.. We won't go into this type of machine any further because it wasn't long before inventors saw the advantages of using, instead 

of slidable connection-changers, mechanisms performing a similar function but of a rotatable 

nature which we now call "electric rotors," and which rotate, usually step-by-step, between 

circular, fixed, contact-bearing members called "stators." Rotors and stators of this type are 

Figure 127. 

153 CQgJ;Di:NTIAla 
REF ID:A63860 

Figure 128a. Figure 128b. 

shown in schematic form in Fig. 129b there being a left-hand stator labeled 1, three rotors 

labelled 2a, 2b, 2c, and a right-hand stator labeled 3. The connections leading away from 

stator 1 toward the left go to the keys of the keyboard; those leading away from rotor 3 toward the right go to the magnets of the printer. About these elements we shall explain some 

details presently. 

In Europe, the first machine using rotors and stators was that developed by a German :firm, 

the Cipher-Machine Company of Berlin, and was appropriately named the ENIGMA. Here's 

a picture of it, Fig. 129c, in which you see a keyboard, a set of eight rotors juxtaposed in line, 

or, as we now generally say, "juxtaposed in cascade," and a printer. This machine was apparently too complicated for practical usage and was superseded by a second model, which 

also printed and was also unsuccessful. One of the difficulties with these two models was that 

a multiple switch with many contacts to be made simultaneously was required in order to 

establish an operative encipher-decipher relationship, so that if in enciphering the letter DP, 

for example, the corresponding key on the keyboard is depressed, and a cipher letter, say F°' 

is printed; then on deciphering the letter F., the corresponding key on the typewriter is depressed, and the plaintext letter DP will be printed. In this machine this could only be done by 

making the current for decipherment traverse exactly the same path through the rotors and 

stators that it had traversed in encipherment. This was the function of the multiple switch 

shown schematically in Fig. 129d, in which a machine with only six characters (A to F) is 

depicted. In the left-hand circuit diagram, DP is being enciphered and produces F.; in the 

right-hand circuit diagram F. produces DP. But the switching mechanisms 4 and 4' in Fig. 

129d make things a bit complicated because they are within one switching member that operates 

in one of two positions, one for encipherment, the other for decipherment, and many contacts 

must be established in one fell swoop, so to speak. I won't go into further details as to its 

construction because a clever inventor of that German :firm came up with a new idea which 

greatly simplified matters, not only in regard to the crypto-component but also in regard to 

the indicating mechanism. We may quickly explain how the matter of simplifying the indicating mechanism was accomplished, namely, by eliminating the printer altogether and replacing it with a simple bank of flashlight type lamps. We'll skip the third model of the 

ENIGMA, which was only a slightly simpler version of the fourth model, which is shown in 

Fig. 130a. This one comprised a keyboard, a bank of indicating lamps, and a set of rotors 

and stators, but no printer. 

154 
J' ~ 

Figure 129a • 

• 

REF ID:A63860 

Figure 129c. 

Figure 129cl. 

155 

Figure 129b. 
REF ID:A63860 

CONFIBF.ll'ff'l1\L 

In Fig. 130a is seen the machine with its cover-plate down. At the front is the keyboard; 

above it, the indicator board, consisting of 26 lamps beneath glass disks upon which letters 

have been inscribed. Above the indicator board are seen four oval apertures with covers, 

through which letters can be seen. To the right of each aperture can be seen the peripheries 

of four metal scalloped wheels, the first being unmarked but the next three being labeled 1. 

A switch lever seen at the right can be set to enc.ipher, decipher, or neutral positions. In Fig. 

130b is seen the machine with the cover-plate removed, exposing the internal crypto-component. Three rotors, labeled 4 in this figure, are seen, and affixed to them are the scalloped 

metal rings, which are not labeled. A fourth scalloped ring, labeled 11 in Fig. 130b, is affixed 

to another rotor-like member labeled 8 in that :figure. This member looks like an ordinary 

rotor in this picture but is really a stator of special construction to be described presently. 

Perhaps it would be useful at this point to show you what ENIGMA rotors look like and these 

can be seen in Figs 131a-c. In each of these rotors there is a circle of 26 equally spaced contact pins on one face of the rotor (Fig. 131a) and a circle of 26 equally spaced contact surfaces 

on the other face (Fig. 13lb). Insulated wires connect the contact pins on one face to the 

contact surfaces on the other face, these connections being made in an arbitrary, systematic, 

or unsystematic manner, depending on certain circumstances into which we need not go. 

When the rotors are juxtaposed as seen in Fig. 13lc, the contact pins on one rotor are brought 

against the contact surfaces on the adjacent rotor, so that an electric current will traverse all 

three rotors via a certain path. The large scalloped rings are for setting the rotors in alignment manually when they are juxtaposed and rotated to form a portion of the key setting (see 

E*Z*R in Fig. 13lc). The toothed metal ring seen in Fig. 131a is associated with a cam 

mechanism so that a rotor will be advanced one step when the preceding rotor has made a 

sufficient number of steps to permit a cam to fall into a notch in the ring. Sometimes a complete revolution will be necessary before this happens, depending upon the initial keysetting. 

The first rotor immediately to the left of the stator at the extreme right in Fig. 131b, however, 

always makes one step with each depression of the key on the keyboard. The advance of the 

rotors is similar to that of the wheels of a counter like that of the odometer on your automobile. 

We come now to the matter of simplifying the crypto-component of the ENIGMA shown 

in Fig. 130b to eliminate the multiple switching mechanism shown in Fig. 129d, without much 

loss in security (or so it would seem, at least). Let us see how this simplification was accomplished in the ENIGMA, by showing Fig. 129d, in connection with the first ENIGMA model. 

For this purpose I show you now Fig. 132, in which the encipher-decipher circuitry is clearly 

seen in a machine having, for illustrative purposes, only three rotors, labeled 1,2,3, rotatable 

between two stators, the one on the left labeled 4, that on the right labeled 5. Stator 4 is fixed 

or nonrotatable in this model, and it has 26 contacts on its left face, only two of which are 

shown. These contacts are connected fixedly to the keys of the keyboard and to the lamps 

of the lampboard. Stator 5 is rotatable, but only manually, and it has 26 contact surfaces on 

its right face, only two of which are shown. But in this stator the 26 contact surfaces are 

inter-connected in pairs by 13 insulated wires passing through the member. Thus, a current 

entering one of the 26 contact surfaces on the right face goes through the stator and returns 

to one of the remaining 25 contact surfaces. For this reason it is called a "refi.ector" and 

serves to return a current that has come from one of the 26 contacts on the fixed stator at the 

extreme right, then through the rotors and into the reflector via one path, returns through the 

rotors and back into the stator via a different path, emerging at one of the 25 other contacts 

on the left face of the stator at the extreme right. This circuitry assures that in a particular 

setting of the machine, if Y JJ = z., for example, then ZJJ = Y., that is, the cipher is reciprocal in nature. It also has as a consequence that no letter can be enciphered by itself, that is, 

Y P• for example, cannot be represented by Y., no matter what the setting of the crypto-component is and this is true of all the other letters of the alphabet with regard to the ENIGMA. 

If you like you may trace the path traversed by the current in Fig. 132 in encipherment and 

decipherment, where Z11 = Y. and Ye = Z11, but Z11 cannot be represened by Z11, nor can Y11 

be represented by Y.. I have already told you briefly about how the rotors are advanced. 

CQHFIBHN'f'IAL 156 
Figure 130a. 

Figure 131a. 

REF ID:A63860 

-~--/ ~ 

~---=-·"=""-~ . ___ ........ ..:!, _________ 

:1-........ ·~-·' • 

Figure 131b. 

Figure 132. 

157 

C0H.Fft)fiN'f'.fA:f; 

Figure 130b. 

Figure 131c. 
REF ID:A63860 

OO:N.PIBBN'l'IAL 

In the ENIGMA shown, the total number of encipherments that can be made before the keysetting of the machine returns to its original setting, as seen through the windows I referred 

to a few moments ago when showing you the first picture of the fourth model ENIGMA, is 

16,900, viz, 263 -262

, and not 268, for technical reasons I won't go into now. 

Power for the electrical circuits is provided by small dry cells in the machine. This model 

enjoyed a fair degree of :financial success, but when Hitler came into power further promotion 

and sales of the ENIGMA were prohibited. Suffice it to say that it became the basis for machines used by the German Armed Forces in World War II. 

In the United States, in about the year 1910, a California inventor named Edward H. Hebern 

(Fig. 133) began to develop cipher machines, but he was merely traveling along roads that had 

thus far led other inventors nowhere. In about the year 1918 he struck out along a new path 

in America. I don't know whether he independently conceived the idea of a machine using 

an electric rotor or had, in his research come across patents covering very recently invented 

European electrical cipher machines. At any rate, Hebern's first application for a patent 

covering a rotor machine, which he called an "electric code," was filed on March 31, 1921, and 

a patent was issued on 30 September 1924. Figure 134 shows the first machine he had built. 

You will note that the crypto-component had but one rotor, and like the early models of the 

ENIGMA it was associated with a printing mechanism, a typewriter operated electrically. 

Hebern's cipher system was also similar in nature with that of the first two ENIGMA modelsa full reversing switch was essential since the electric current had to traverse exactly the same 

path in decipherment as it had in encipherment. I don't think that he ever conceived the 

idea of using a refiector; perhaps he was too late. At any rate, he never incorporated that 

idea in any of his machines. Moreover, I don't think he had any idea as to the cryptologic 

advantages and disadvantages of a crypto-component using a "single traverse" or "straight 

through" system of rotors, as compared with one using a "double-traverse" or "twice-through" 

system of rotors with a reflector. But we won't go into that here, for it's a pretty involved 

piece of business. 

But Hebern's rotors had a virtue not possessed by those of the ENIGMA machines, and 

not incorporated in the rotors of the latter, namely, the wirings of the rotors could readily be 

changed by the user of the Hebern machine, a feature of great importance in cryptosecurity 

(Fig. 135). Hebern interested our Navy in his 3-rotor model (Fig. 136) and as a result of 

conferences with Navy cryptanalysts he built the 5-rotor model which is seen is Fig. 137. Another very important security feature I have thus far failed to mention as regards the Hebern 

rotors was that they could be inserted in a "right-side up" or in an "upside-down" position 

in the machine, which could not be done with the ENIGMA rotors. The Navy liked the 5-

rotor model, even though it was not a printing machine, assuming properly that this could be 

added later on. Therefore, the Navy placed a purchase order for two such machines on 30 

July 1921 and was considering purchasing a rather large number of them later. Lieutenant 

Strubel, then Chief of the Navy's Code and Signal Section of the Office of Naval Communications but now a retired Vice Admiral, asked me to study the machine for its cryptosecurity. 

Navy had but two machines, neither of which could be made available, so I induced the Chief 

Signal Officer to buy a couple of them for Army study. The order was placed on 7 October 

1924. The rotor wirings of the Army's machines were altogether different from those of the 

Navy, a fact which I discovered simply by asking Strubel to encipher a few letters on his machine, using settings I specified. After some study I reported that in my opinion the security 

of the machine was not as great as Navy thought. The result was a challenge, which I accepted. Navy gave me ten messages put up on its machine, and I was successful in solving 

them. There isn't time to go into the methods used, but if you are interested you can find 

them described in my brochure entitled Analysis of a Mechanico-Electrical Crypt;ograph, Part I 

(1934), Part II (1935). 

Hebern built several more models for Navy, and these had printing mechanisms associated 

with them, but Navy dropped negotiations with Hebern when it became obvious that he was 

158 
c 

REF ID:A63860 

CQNPIBFJN'i'I2U;; -. --· r •;t- ...... • _ .. _... 

Figure 133. 

not compet.ent to build what Navy wanted and needed. Navy then established its own cryptographic research and development unit at what is now known as the Naval Weapons Plant in 

Washington. Army developed at the Signal Corps Laboratories at Fort Monmouth a machine known as Converter M-134, and here's an illustration (Fig. 138) showing what it looked 

like. Army and Navy went separate ways in such work for a number of years but :finally, in 

1938 or 1939, close collaborating brought as a result an excellent machine which was developed 

and produced in quantity by the Teletype Corporation in Chicago. This machine was distributed and used very successfully by all our Armed Forces from 1940 to the end of World 

War II and for some years thereafter. In accordance with Navy nomenclature it was designated as the ECM Mark II, ECM standing for "electric cipher machine"; in the Army it was 

designated as the SIGABA, in accordance with a nomenclature in which items of Signal Corps 

cryptographic material were then given short titles with the initial trigraph SIG. 

The ECM-SIGABA is a rather large machine requiring a considerable amount of electric 

power and much too heavy to be carried about by a signal operator performing :field service. 

It was safeguarded with extreme care and under strictest security regulations during the whole 

period of World War II operations. None of our Allies was permitted even to see the machine, let alone have it. The British had their own electric cipher machine, which they called 

TYPEX. In order to facilitate intercommunication between U.S. and British forces, adaptors 

were developed so that messages could be exchanged in cipher between American and British 

units. This system of intercommunication worked satisfactorily and securely. 

159 
REF ID:A63860 

C<»ilFIDE'N'H·l .. I:. 

Figure 134. 

Figure 135. Figure 136. 

160 
REF ID:A63860 

.. 

- -----

• ~!i!!iiii~-- . ' 

-,:_,. • I•• 

=""" 

Figure 137. Figure 138. 

Figure 139. 

161 GONPIBBN'ftAL 
REF ID:A63860 

Certain improvements in the method of usage and the development of special components, 

to be associated with the ECM-SIGABA for automatic decipherment by perforated tapes, 

were introduced during the wartime employment of these machines. But the SIGABA-ECM 

as originally developed and produced became obsolete some years after the close of hostilities 

when newer and better machines developed by NSA cryptologists and engineers replaced them, 

but not because there were ever any indications that messages enciphered on the machine had 

been deciphered by the enemy. As a matter of historical fact, it may be stated that all enemy 

efforts to solve such messages were fruitless, and it is also a fact that no machines were ever 

captured by the enemy; nor where there ever any suspicions that a machine had been exposed 

to enemy inspection at any time. Once and only once were there any apprehensions in this 

regard, when, through a careless disregard of specific instructions, a truck and an attached 

trailer, in which this machine and associated material were housed, were stolen during the 

night when parked in front of the headquarters of the 28th Division during the Battle of the 

Bulge. A great search was instituted, during the course of which a river was diverted, and 

the trailer, with all its contents intact, was found resting on the former bed of the diverted 

stream. The episode terminated in court-martial proceedings and there were no further incidents of this sort. Let me add that such apprehensions as were entertained at the time of 

this temporary loss of custody of the machine were based not upon the possibility that its usefulness was at an end but upon the fear that the Germans would make "Chinese copies" of 

it and thus be in a position to turn our very valuable weapon against us. 

About :five years before the SIGABA was put into service, the Army's need for a small cipher 

machine for :field use became obvious. The strip cipher system was not suitable for this purpose, nor was the Army's first keyboard-operated electrical rotor machine, Converter M-134, 

suitable, for reasons already indicated in connection with the SIGABA. The sum of $2,000 

was allotted by the Army to the Chief Signal Officer for the development of a cipher machine 

small enough to be suitable for field usage but also affording adequate security. The funds 

were naturally turned over to the Signal Corps Laboratories at Fort Monmouth, New Jersey, 

for this development. The military director of the laboratories, spurning all proferred technical guidance or assistance from the Signal Intelligence Service and deciding that his staff had 

sufficient know-how without outside assistance, developed a machine which required no electricity, being all-mechanical. On its completion the model was sent to the Signal Intelligence 

Service for a cryptosecurity test. Two short messages were enciphered by the Chief of the 

SIS, using settings of his own selection. He then handed the messages and the model over to 

me as Technical Director, and I turned them over to two of my assistants. The reason for 

turning over the model with the messages was that it must be assumed that under :field conditions machines will be captured. One of the two test messages was solved in about 20 minutes; the other took longer-35 minutes. This test brought an ignominious end to the SCL 

development, brought about by the failure on the part of the military director of the SCL to 

recognize that cryptographic invention must be guided by technically quali:fied cryptanalytic 

personnel. Unfortunately, all the available funds had been expended on this unsuccessful 

attempt; none was left for a fresh start on a development with technical guidance from the 

SIS. It was about this time that a small mechanical machine which had been developed and 

produced in quantity by a Swedish engineer in Stockholm named Hagelin (Fig. 139) was 

brought to the attention of the Chief Signal Officer of the U.S. Army by a representative of 

the Hagelin firm. The SIS was asked to look into it and, as technical director, I turned in an 

unfavorable report on the machine for the reason that although its cryptosecurity was theoretically quite good, it had a low degree of cryptosecurity if improperly used-and practical 

experience had taught me that improper use could be expected to occur with sufficient frequency to jeopardize the security of all messages enciphered by the same setting of the machine, 

whether correctly enciphered or not. This was because the Hagelin machine operates on what 

is termed the key-generator principle, so that when two or more messages are enciphered by 

the same key stream or portions thereof, solution of those messages is a relatively simple matter. Such solution permits recovery of the settings of the keying elements so that the whole 

CONPlf>tlN'HAi:. 162 
... 

REF ID:A63860 

OON.FIBEN'f'I2\L 

stream can be produced and used to solve messages which have been correctly enciphered by 

the same key settings, thus making a whole day's traffic readable by the enemy. I tried to 

assure the CSO that my opinion was not motivated by a factor commonly called "NIH" -

"not invented here," but I was overruled by my military superiors, and properly so, because 

neither the SIS nor the SCL had developed anything that was better than the Hagelin machine, 

or even as good, with all its mechanical deficiences and cryptographic weaknesses Laken into 

consideration. Accepting, though somewhat reluctantly, the well-considered directive of the 

CSO, the SIS pointed out where improvements could be made, and the desired modifications 

were incorporated in the machine, which became known as Converter M-209. Over 100,000 

of them were manufactured in 1942-1944 by the Smith-Corona Typewriter Company, at Groton, 

New York. Here's an illustration (Fig. 140) showing the machine, which was extensively used 

by all our Armed Forces during World War II, and here's another (Fig. 140) showing its internal mechanism. It turned out that under :field conditions the fears upon which I had based 

my personal rejection of the Hagelin machine proved to be fully justified- a great deal of 

traffic in it was solved by the Germans, Italians, and Japanese. If I was chagrined or suffered 

any remorse when I learned about the enemy successful attacks on M-209 traffic, those feelings were generated by my sense of having failed myself to think up something better than 

the M-209 despite the shortsighted attitude of the military director of the SCL. 

---- --1 

\'\ -~ \ \• 

Figure 140a. Figure 140b. 

With the introduction of printing telegraph or teleprinting machines for electrical communications, the need became pressing for a reliable and practical cryptographic mechanism to be 

associated or integrated with such machines. The :first apparatus of this sort in the U.S., 

shown in this photo (Fig. 141), was that developed by the American Telephone and Telegraph 

Co., in 1918, as a more-or-less simple but ingenious modification of its ordinary printing telegraph. First, a few explanatory words about the basic principles of the modern teleprinter may 

be useful. This principle employs what is called the "Baudot Code," that is, a system in 

which permutations of two different elements taken in groups of :five are employed to represent 

characters of the alphabet. Curiously enough, Francis Bacon was the first to employ such a 

"code" way back in the early 17th Century, and I showed you the one he used in Lecture No. 

II (see Fig. 31 on p. 34). These two elements in Bacon's "code" were a's and b's; he used but 

24 of the 32 permutations available (26 = 32). For electrical communications the two elements 

may be positive and negative currents of electricity, or the presence and absence of current, 

the latter system being often referred to as being composed of "marking" and "spacing" elements, respectively. The illustration below (Fig. 142) depicts the Baudot or "5-unit code" in 

the form of a paper tape in which there are holes in certain positions transverse to the length 

163 
REF ID:A63860 

Figure 141. 

7 : • u c ~4£ S H ' & F 

- -~:it 

• 

Mach me 

f'orfurator 

Kry lape 

rransmrtter;; 

... ---Key Tapes 

? 2 

2 ' . . . . . . . . • • • • • • • • • • • • ....... • • • • . ..... ............................................................................ . i ••• ·:: ·:1 :; ··: •• :. ·: :. :: !::. 

TAPE SHOWING PRINTING TELEGRAPHIC CODE 

Figure 142. 

of the tape. The holes are produced by a perforating mechanism; the small holes running the 

length of the tape are "feed-holes" by means of which the tape is advanced step by step. You 

will note that there are :five levels on which the perforations appear. The letter A, for example, 

is represented by a perforation only on the 1st and 2nd levels, the 3rd, 4th and 5th levels remaining unperforated; the letter I is represented by holes in positions 2 and 3, no holes on the 

other three levels, etc. The English alphabet uses 26 of the 32 permutations; the remaining 6 

permutations are used to represent the so-called "stunt characters," which I will now explain. 

The third and fourth characters from the right-hand end of the tape are two permutations 

labeled "letters" and ":figures," respectively. These are equivalent to the "shift" and "unshift" keys on a typewriter keyboard, for "lower" and "upper" case. When the "letters" key 

is depressed, the characters printed are the 26 letters of the alphabet (all capital letters); when 

the "figures" key is depressed the characters represented are similar to those printed on a 

typewriter when the "shift" key is depressed. The second, third, and fourth permutations at 

the left-hand end of the tape are also stunt characters and represent "line feed," "space," and 

"carriage return," and they perform electrically in a teleprinter what is done by hand on a 

typewriter: "line feed" causes the paper on which the message is printed to advance to the 

next line; "space" does exactly what depressing the space bar on a typewriter does, etc. When 

there are no holes anywhere across the tape, the character is called a "blank" or "idling" character-nothing happens; the printer does no printing, nor is there any "stunt" functioning by 

the printer, but the tape merely advances. 

In modifying the standard printing telegraph machine to make it a printing telegraph cipher 

machine, or, to put the matter in a slightly different way, in developing the printing telegraph 

cipher machine the American Telephone and Telegraph Company was fortunate in having at 

its disposal the services of a 23-year old communications engineer named Gilbert S. Vernam, 

(Fig. 143) who conceived a brilliant principle and an automatic method for enciphering teleGONFIBEIN'f fAL 164 
.. 

a 

REF ID:A63860 

CONPIMN't'IAL 

printer communications. The principle and method turned out to be so useful and valuable, 

not only in the U.S. but also internationally, that it has come to bear his name and is often 

referred to as the "Vemam principle," the "Vernam rule," the "Vemam mod-2 addition," etc. 

V ernam saw that if in accordance with some general but invariant rule the marking and spacing 

elements of a 5-unit code group were combined one by one with those of another 5-unit code 

group, which would serve as a keying group, and the resultant 5-unit group transmiLLed over 

a circuit and combined at the receiver with the same keying group in accordance with the 

same general rule, 18 the :final resultant would be the original character. Vernam conceived 

the idea early in 1918, or perhaps in late 1917. I have a copy of Vemam's circuit diagram, 

dated and witnessed on 27 Feb 1918, but the application for a patent thereon, with his name 

as inventor, was :filed in the U.S. Patent Office on 13September1918, and Patent No. 1,310,719 

was granted on 22 July 1919, covering the invention entitled a "Secret Signaling System." 

The following more detailed description of Vernam.'s patent on the foregoing cipher system 

is extracted from a paper19 written by one of the A. T. & T. Company's engineers who was associated with Mr. V emam. at the time the invention was conceived and who, a few years after 

retirement from that company, became one of NSA's consultants: 

"This patent describes an "on-line" system, each character being enciphered, immediately 

transmitted, and in turn deciphered without delay at the receiving terminal. Thus, characters 

of a message in perforated tape form are automatically combined with other or key characters 

which are transmitted over the circuit. At the receiver an identical group of key characters is 

used to provide signals for combination with the arriving signals, character by character, to produce the original message. The combining rule for these operations disclosed in the patent was 

one in which like code elements produced "spaces" and unlike elements, "marks," as shown below. 

The cipher message tape prepared in this way is unintelligible in form and may be sent to the 

receiving station by messenger or by mail, or if desired, it may be transmitted by wire or radio 

and reproduced by another machine perforator at the receiving point. The cipher tape is there 

run through the message transmitter, where its characters combine with those of a duplicate key 

tape to reproduce the original message, which will be printed out in page form and in "plain 

text." 

LENGTH OF KEY TAPE 

With the system as described above, the key tape must be at least as long as the sum of all 

the message tapes used with it, as the messages will lose their secrecy to some extent if the key 

tape is used repeatedly. The use of a short repeating key may give sufficient secrecy for some 

uses, however. 

A roll of tape 8 inches in diameter contains about 900 feet of tape and would serve to encipher 

about 18,000 words counting five printed characters and a space per word, without repeating the 

key. If sent at an average speed of 45 words per minute, this number of words would require 

400 minutes or nearly 7 hours to transmit. 

In order to reduce the amount of key tape required for handling large amounts of traffic, the 

"double key" system was devised.20 In this system two key tapes are used, the ends of each tape 

being glued together to form a loop preferably about seven feet in circumference. The tapes 

should differ in length by one character or by some number which is not a factor of the number of 

characters in either tape. A separate transmitter is used for each tape, and the characters of 

the two key tapes are combined, by a method similar to that shown in Figure 144, with those of 

the message tape to form the cipher message. 

The result is the same as though the two key tapes were first combined to produce a long single 

non-repeating key, which was later combined with the message tape. This long, single key is 

not, strictly speaking, a purely random key throughout its length as it is made up of combinations of the two original and comparatively short key tapes. The characters in this key do not 

18 In this system which uses only two different symbols or elements, the so-called "binary code," the combining rule is its own inverse. 

19 Parker, R. D. "Recollections Concerning the Birth of One-Time Tape and Printing-Telegraph Machine 

Cryptography." NSA Technical Journal, Vol. I, No. 2, July 1956, pp. 103-114. 

20 By L. F. Morehouse, an A.T. & T. Company equipment engineer. See U.S. Patent No. 1,356,546, "Ciphering System," granted 26October1920-WFF. 

165 OON.PfMN't'IAL 
REF ID:A63860 

Figure 143. Figure 144. 

repeat in the same sequence at comparatively short regular intervals, however, as would be the 

case if only one key tape loop were used. 

The number of characters in this equivalent single key is equal to the product of the number 

of characters in the two tape loops, and may easily exceed 600,000 before any part of the key 

begins to repeat. If proper care is taken to use the system so as to avoid giving information to 

the enemy regarding the lengths of the two key tape loops or their initial settings and to avoid 

the possibility of ever re-using any part of the resultant single key, this system is extremely difficult to break even by an expert cryptanalyst having a large number of messages and full 

knowledge of the construction of the machine and it.s method of operation." 

The foregoing double-key-tape system was placed into operation in 1918, on three start-stop 

circuits which were used for intercommunication among four stations serving Washington, 

New York, Hoboken and Norfolk, and which according to Parker [see footnote 20 above,] "continued in operation for many months, even after the end of the war." In addition, a Signal 

Corps Company was organized to go to Europe with new equipment for installation of printingtelegraph circuits in France. This Signal Company was about ready to sail when the Armistice 

was signed November 11, 1918. 

Upon my return to Riverbank in April 1919, after being demobilized, I became an interested 

party in a rather warm argument conducted by letters exchanged between Colonel Fabyan, 

the Chief Signal Officer, the Director of Military Intelligence, and the War Department, regarding the cryptosecurity of the cipher printing telegraph system as used by the Signal Corps. 

The argument ended by successfully meeting a challenge by the Signal Corps to prove Fabyan's 

contention. The challenge consisted in sending Fabyan, on 6 October 1919, and requesting 

him to solve, the cipher tapes of about 150 messages selected from one day's traffic in the 

system. On 8 December 1919 Fabyan sent a telegram to the Chief Signal Officer notifying 

him that solution had been accomplished. In order to prove that this was true, I sent a perforated cipher-message tape to each of the officers named above. In order to decipher these 

messages the Chief Signal Officer had to use his own key tapes, thus proving that not only had 

Riverbank solved the system but had recovered both key tapes which had been employed in 

enciphering the challenge messages, so that Riverbank was in a position to produce the plain 

text of any of the latter on request, if further proof of solution was needed or desired. I wrote 

a monograph on the solution, consisting of a basic paper of 21 typewritten pages, an Addendum 

1 of 10 pages, an Addendum 2 of 25 pages and an Addendum 3 of six pages; a copy of each of 

these documents was sent to Washington. The solution was accepted with mixed feelings in 

Washington, especially on the part of Brigadier General Marlborough Churchill, the Director 

of Military Intelligence, who had signed a letter to the Chief Signal Officer, dated 8 August 

166 
.. 

REF ID:A63860 

OOHPIBHN'ffl\L 

1918 prepared by Capt. Yardley to the effect that the cipher system in question "is considered 

by this office to be absolutely indecipherable." 21 General Churchill had the duty and courtesy 

to write a congratulatory letter to Colonel Fabyan, dated 24 March 1920, the final paragraph 

of which is as follows: 

"Your very brilliant scientific achievement reflects great credit upon you and your whole personnel. It would be impossible to exaggerate in paying you and Riverbank the deserved tribute for this very scholarly accomplishment." 

The paper by Mr. Parker (see footnote 20) closes with the following :final paragraph: 

"Perhaps some day Mr. Friedman will tell of the part that he and the Riverbank Laboratories 

played in the cryptanalytic phase of this development." 

Mr. Parker was not aware of the fact that what he suggested had not only been done once, 

but twice. The :first time was immediately after the solution when copies of the writeup mentioned a moment ago on page 101 had been sent to Washington where they had met the fate 

that often happens to documents of limited or special technical interest-complete disappearance in the voluminous files of bureaucracy. The second time was soon after the end of hostilities of World War II, when it was discovered that a certain outfit I won't name was using 

the double-tape keying system for its teleprinter communications. I rummaged through my 

own :files and uncovered the handwritten manuscript of certain parts of what I had written at 

the close of the successful solution of that system while at Riverbank. My second write-up 

is a classified document, dated 21 July 1948, the subtitle of which is "Can Cryptologic History 

Repeat Itself?" It is possible that this write-up can be made available to those of you who 

are interested in reading it, if proper authority grants permission. 

Mr. Parker's paper (see footnote 20, above) devotes a good deal of space to the contention 

that the only reason why the double-tape keying method was adopted was that the Signal 

Corps and specifically its representative, Colonel Mauborgne, "complained about the difficulties that might be experienced in the preparation and distribution of one-time random key 

tapes and seemed inclined to disapprove of the proposed system because of these difficulties. 

Since the system, when properly used, seemed obviously to be one which gave absolute secrecy, 

a discussion arose on the value of the system and on methods which might be devised for the 

production and distribution oflong one-time key tapes having characters arranged at random." 

Parker points out that the original method of use contemplated the use of long tapes of this 

nature and that he and his associates felt that the problem of producing and distributing long 

tapes "while presenting a challenge, was not impractical." I am glad to admit that they 

were right, because during World War II and for years afterward tapes of this nature were 

produced by special machinery (in some cases as many as :five copies being perforated and the 

sections numbered automatically in a single operation). Distribution of and accounting for 

the tapes proved practical, too, and aside from an occasional error involving the re-use of a 

once used tape, absolutely secure intercommunication by radio printing telegraphy was assured 

and was used between and among large headquarters where the volume of traffic justified the 

use of this equipment. The principal advantage was the simplicity of crypto-operations-no 

rotors to be set, no setup of rotors to be enciphered, no checking of encipherment by deciphering the message before transmission, etc. 

The A. T. & T. Company Printing Telegraph Cipher equipments purchased by the Signal 

Corps were withdrawn soon after Riverbank proved the double-key-tape system insecure. 

The machines went into storage, when in due course most of them were dismantled. But 

after I left Riverbank at the end of 1920 and had joined the Chief Signal Officer's staff in 

11 The letter consisting of a single paragraph stated: "1. The mechanical means of enciphering messages 

with an arbitrary, meaningless running key of 999,000 letters, provided no two messages are enciphered at 

the same point on the tape as explained to Major Mauborgne, Signal Corps, and Captain Yardley, Military 

Intelligence Branch, by officials of the American Telegraph and Telephone Company, is considered by this 

office to be absolutely indecipherable." 

167 GONPIBEN'ffAL 
REF ID:A63860 

CQHFIBHN'f'IAL 

Washington, I induced the Chief Signal Officer to resuscitate two equipments. These I employed, believe it or not, in compiling codes, called Division Field Codes, for use in training or 

in an emergency. I won't undertake to explain how I performed this stunt, for it was a stunt, 

but it worked very successfully. The codes were duly printed, issued and used until there was 

no longer any need for codes of this type. 

Cipher printing telegraphy was placed upon the shelf and more or less forgotten by Signal 

Corps communications engineers from 1920 until soon after Pearl Harbor. However, the 

leading members of the S. I. S. maintained a theoretical cryptanalytic interest in such equipment, and in 1931 there came an opportunity to test such theories as were developed by them 

when a machine produced by the International Telephone and Telegraph Company evoked the 

interest of the Department of State as a possible answer to the needs of that Department for 

rapid and secure cryptocommunications by radio. The Secretary of State requested the 

Secretary of War to study the machine, which was to be associated with a standard teleprinter, 

and to study it only from the point of view of security. For this purpose messages enciphered 

by the Chief of the Communications and Records Division of the Department of State were 

provided. Here are two pictures of the teleprinter attachment. (Figs 145a, and 145b.) It is a 

source of satisfaction to be able to tell you that the S.l.S. quickly solved the test messages 

and therefore reported that the machine was quite insecure; but it is with much regret that I 

must now tell you who invented and developed the machine. It was a retired officer of the 

Signal Corps and none other than my old friend Colonel Hitt. I was as embarrassed to tell 

Figure 145a. Figure 1456. 

him about the results of our test as he was to force himself to listen to what I had to say about 

the inadequacies of his brain child. As is so often the case, when a competent technician has 

to neglect his technical studies because of the pressure of administrative duties, he unfortunately finds it very difficult to keep abreast of new developments and progress in a :field in 

which he was at one time an expert. The I. T. & T. Company, having spent a great deal of 

money on the development of a machine which hardly presented any room at all for improvement because the principles underlying it were so faulty, dropped further work on it. Colonel 

Hitt, I am glad to say, readily survived the disappointment and was well enough in 1942 to 

be able to return to active duty during World War II and retired a second time at the end of 

hostilities. He lives a quiet life now, on a small farm near Front Royal, Virginia. 

Beginning about 1938, Mr. Frank B. Rowlett, one of my associates, and I kept urging that 

there was or would be real need for new and improved machines for protecting teleprinter communications. There was not only a complete lack of interest in such apparatus, but what was 

perhaps a more important factor in the failure to continue work in this :field was the lack of 

Signal Corps funds for research and development for such work. 

Our more-or-less sudden entry into World War II, after 7 December 1941, immediately 

brought a great need for cipher printing telegraphy, especially for radiocommunication, but 

CONPIB~AI. 168 
,. 

" 

... 

REF ID:A63860 

GONPIBBN llAL 

there was no apparatus for it whatever-not a single one of those A. T. & T. Company machines of 1918-1920 was in existence. But the S.I.S. did have drawings in readiness, and the 

development of the machines was given as a priority task to the Teletype Corporation, because 

that :firm had proved that it had the necessary know-how when it produced the SIGABAECM's for us. Navy had less need for cipher printing telegraphy than Army because the use 

of printing telegraphy by radio was then not practicable for ships at. sea. However, Navy did 

have a need for such apparatus for its land communications and joined Army in the procurement thereof. The machines were produced with a remarkable speed by the Teletype Corporation. Most of them were allotted to Army, a few to Navy. The Army called the machine the 

SIGCUM; the Navy called it CSP-1515. Under heavy use in service, improvements were 

made both in regard to mechanical and electrical features and in regard to methods of keying, the 

use of indicators, etc. But I must tell you that before those machines became available in 

quantity there was only one recourse: we went back to the use of the double-key-tape method 

using standard teletype apparatus. The cipher was practically the same as it was in 1920, but 

we had safer methods of key-tape production and indicators for their use. The S.I.S. and the 

equivalent unit in Navy were not happy because operator's errors left messages open to solution, 

so that when the new cipher machines were ready they were pressed into service as soon as possible, priority being given to circuits with heavy traffic. 

Cryptographic equipments of the foregoing type fall in the category of apparatus for protecting Uteral cryptocommunications because the latter employ letters of the alphabet; but 

apparatus for protecting cifax transmissions, that is, picture or facsimile transmissions, and 

apparatus for protecting ciphony transmissions, that is, telephonic communications, were 

also developed. But there isn't time to go into details with regard to machines and apparatus 

for these last two categories of crypto-equipments although the history of their development is 

rather fascinating and very important. I cannot refrain, however, from adding, that in every 

case except one, the apparatus was produced by commercial research and development :firms 

with direct guidance from the cryptologists of the Army and the Navy. The one exception is, 

I believe, in the case of the extremely high security ciphony system and equipment developed 

and built by the A. T. & T. Company. It was called SIGSALY. There were six terminals, 

each of which cost over $1,000,000. But NSA cryptologists and engineers have produced 

smaller and better equipments based upon SIGSAL Y principles, and such equipments are bound 

to play extremely important roles in any wars in the future. 

So much for the history of the developments and progress in cryptographic apparatus at this 

point. I shall return to that phase of cryptologic history before the close of this lecture. Right 

now I shall say a few words about the history of the developments and progress in cryptanalytic 

apparatus. 

The solution of modern cryptocommunication systems has been facilitated and, in some 

cases, made possible only by the invention, development, and application of highly specialized 

cryptanalytic machinery, including apparatus for intercepting and recording certain types of 

transmissions before crytanalysis can even be undertaken. One must understand the basic 

nature of the problem which confronts the cryptanalyst when he attempts to solve one of these 

modern, very complex cryptosystems. First of all he must be given the cryptocommunications 

in a form which makes them visible for inspection and study. Usually they are characters (letters or numbers) in the case of literal communications, or they are electrical signals of a recordable type in the case of cifax or ciphony communications. Next he must have available to him 

instrumentalities that will assist him in his analytical work, such as machinery for making frequency counts, comparisons of sequences, etc., and this, in the case of complex systems, must be 

done at high speed. Cryptanalysis of modern cryptosystems requires testing a very great number of assumptions and hypotheses because sometimes astronomically large numbers of possibilities, i.e., permutations and combinations, must be tested one after the other until the correct 

answer is found. Since the advent of high-speed machinery for such purposes, including electronic digital computers about which so much is being heard and read nowadays, the cryptanalyst isn't discouraged by these astronomically great numbers of possibilities. 

169 
REF ID:A63860 

Perhaps long before my time cryptanalysts in Europe discovered that the use of sliding strips 

of paper could sometimes facilitate reaching a solution to a cryptanalytic problem, but so far as 

I am aware the very first cryptanalytic aid made in the U.S. is the one shown in Fig. 145, which 

is a picture of what I made at Riverbank and which I called the Polyalphabet. It was useful 

in solving ciphers which today are regarded as being of the very simplest types. When I came 

to Washing Lon after leaviug Riverbank., I wasn't troubled by a plethora of ideas for cryptanalytic 

aids-I was preoccupied with devising and inventing cryptographic aids and machines. But 

I did now and then develop and try out certain ideas for cryptanalytic aids, frequency counters, 

comparison or coincidence machinery, and the like. Why didn't I think of IBM machines? I 

did, but what good did that do? Did the Signal Office have any such machines-or even one 

dollar for their rental? You know the answer to that without my spelling it out. There 

wasn't any use even in suggesting that IBM machines could be of assistance to me-remember, 

now, that I'm talking about the yems from 1921 to 1933, and in the last-named year we were in 

the depths of a great economic depression. But one day in the summer of 1934 I learned by a 

devious route (Army and Navy were not then sharing secrets) that the Navy Code and Signal 

Section had an IBM machine or two, and my chagrin was almost unbearable. Not long afterwards I learned that a certain division of the Office of the Quartermaster General in the MuniI 

' ( ! • . I • • 

~ : ' ~ o ~ • 1, • I ' ~ 

1 . · 1 . ~ I . . . . I i. . : I ! . : ' : 

: ~ : . . . . . , . I I : : ; 

: . I : I · : . ~ ! : . , 1 , ' ; ' : ~; 

~ : ; : j I: ; · ;II : . { I: t j ,:Ii : ; 111 i > .. :-. ~ i i 1 4 ._ ~ ~ 1 , ~ ~ ~ '1 ,, • 1 • 

UNITED STATES WAR COLLEGE , 

·-·· .... , .c.. .... _ -

- --- -- -------

Figure 146. 

tions Building had an IBM installation which had been used for accounting purposes in connection with the C.C.C.-the Civilian Conservation Corps, established to provide work and subsistence for young men who could find no jobs in the depression. I also learned that a new officer had 

just been assigned to head that particular division-and that he just had no use for the new fangled-ideas of his predecessor and wanted to get rid of those nasty IBM machines. But the con170 
.. 

• 

REF rn':A63860 

CONfi'IBEN'f'I2\L 

tract with IBM still had some months to run before the lease expired and either the machines 

would sit idle or the Government would lose money by terminating the contract before the due 

date of expiration. This annoyed me, but it also gave me an idea and I wrote the following 

memorandum: 

30 October 1934 

Major Akin: 

In many years service here I have never once "set my heart on" getting something I felt 

desirable. But in this case I have set my heart on the matter because of the tremendous load 

it would lift off all our backs. 

The basic idea of using machinery for code compilation is mine and is of several years' standing. The details of the proposed system were developed in collaboration with Mr. Case of the 

Int. Bus. Machines Corp. 

I regard this as one of my most valuable contributions to the promotion of the work for which 

we are responsible. 

Please do your utmost to put this across for me. If you do, we can really begin to do worthwhile cryptanalytic work. 

Attached to the memo was a brief explanation amounting to what I've told you about that 

IBM installation in the Office of the Quartermaster General. Note that I placed the emphasis 

upon the burden that would be lifted from cryptographic work by using the IBM machinery, 

thus leaving more time for cryptanalytic work. This was because the responsibilities of the 

S.I.S. for cryptanalytic operations were at that time restricted purely to theoretical studies. 

Studies on cryptanalytic work on foreign cryptosystems had been a responsibility of G-2 of the 

General Staff until 1929, when that responsibility had been transferred to the Chief Signal Officer 

and the Signal Corps in the year named. But the Signal Officer had very little money to use 

for that purpose, and, besides that, the Army Regulation applicable thereto specifically restricted 

cryptanalytic operations on foreign communications to wartime. And more to the point was 

the fact that there was no material to work on even if funds were available, because the Army 

had at that time no intercept stations whatever, anywhere in or outside the U.S. But that's 

another story, and I'll proceed to the next point, which is that my memo to Major Akin produced 

results. Just a half month after I wrote and put it in his "In" basket I got the machines moved 

from the Office of the Quartermaster General to my own warren in the Office of the Chief Signal 

Officer! That memo must have been potent magic. 

Once having demonstrated their utility to the Chief Signal Officer, the almost prematurely 

terminated contract with IBM was renewed-and soon expanded. I don't know how we could 

have managed without such machines during World War II. 

We built or had built for us by IBM and other concerns adaptors to work with standard IBM 

machines; we constructed or had constructed for us by commercial :firms highly specialized 

cryptanalytic apparatus, machines and complex assemblies of components. Under wartime 

pressures fantastic things were accomplished and many were the thrills of gratifying achievement when things that just couldn't be done were done-and were of high importance in military, 

naval and air operations against the enemy. 

Even were time available I couldn't show you pictures of some of the high-class gadgets we 

used, neither is it permissible to say more than I have already said about them, even though it 

is no longer a deep secret that electronic computers are highly useful in cryptologic work. 

To the layman the exploits of professional cryptanalysts, when those exploits come to light as, 

for example, in the various investigations of the attack on Pearl Harbor, are much more fascinating than those of cryptographers, whose achievements in their :field appear in comparsion to be 

dull or tedious to the layman. But long consideration of the military importance of COMSEC as 

against COMINT leads me to return to something I mentioned at the very begininng of this 

lecture, when I made a statement to the effect that cryptography and cryptanalysis represent 

the obverse and reverse faces of the same single coin. In closing this lecture I will expand that 

statement a bit, and in so doing perhaps formulate a dictum which we may call the law governing the minting and usage of the cryptologic combat coin. It would run something like this: 

171 CONPIB~ 
REF ID:A63860 

CQ:NRBHN'f'In:L 

When an officer is selected to command a :fighting unit, an efficient appointing authority 

gives him and entrusts into his care a top secret, magic talisman of great potency, a coin which 

is called his cryptologic combat coin, and which, as is usual in the case of all but trick coins, has 

two faces, a COMINT face and a COMSEC face. When given to him that coin should be in mint 

condition, it should be bright and shiny on both faces, and he should strive his utmost to keep 

them both that way. If, to begin with, he is given a coin that is tarnished a bit on both faces, he 

is really starting out with a great handicap, no matter how good he and his forces are in respect 

to size, equipment, training and ability. If he keeps both faces bright and shiny, he stands a good 

chance of winning a battle even if his forces are inferior in size, etc., compared with those of the 

enemy. But if he lets either face of his coin become dull from indifference, carelessness, or 

ignorance, he will almost surely lose the battle, even if his forces are superior in size, etc., compared with those of the enemy. 

As a remarkable example of the validity of the foregoing dictum, an example that comes 

directly from the two Japanese Navy officers who wrote Midway: The Battle f:kat Doomed Japan 

(see footnote 12 above), let me quote the initial paragraphs of the Preface to their book (p. xiii): 

"For Japan, the Battle of Midway was indeed a tragic defeat. The Japanese Combined Fleet, 

placing its faith in "quality rather than quantity," had long trained and prepared to defeat a 

numerically superior enemy. Yet at Midway a stronger Japanese force went down to 

defeat before a weaker enemy. 

Not only were our participating surface forces far superior in number to those of the enemy, 

but the initiative was in our hands. Nor were we inferior, qualitatively, in the crucial element 

of air strength, which played the major role throughout the Pacific War. In spite of this we 

suffered a decisive defeat such as the modern Japanese Navy had never before experienced or 

even dreamed possible." 

Earlier in this lecture (seep. 134), I quoted two other paragraphs from this same book, in 

which the Japanese authors make perfectly clear the reasons for the loss of the Battle of Midway, reasons which have also been stated by other writers. The cryptologic combat coin our 

Navy entrusted to Admiral Nimitz was highly polished and bright on both sides; the one the 

Japanese Navy entrusted to Admiral Yamamoto was dull on both sides to begin with. Admiral 

Yamamoto not only didn't even know how tarnished it was; he lost his life because of his ignorance a couple of years later. Neither he nor his superiors had the experience and knowledge that 

were necessary to polish up that coin. It took almost ten years for the truth of that dictum 

I formulated for you a moment or two ago to become clear to the Japanese Navy. Had they 

taken quick and full advantage of the unfortunate leakage of the vital COMINT facts soon after 

the Battle of Midway, they could and perhaps would have come to the proper conclusions long 

before they did. Who knows what the results might have been, and the effect thereof, on the 

outcome of the war in the Pacific? 

Hardly anything of importance in the cryptologic battles of World War II escaped the attention of Winston Churchill, who even 'way back in 1915, when he was First Sea Lord of the 

British Navy in World War I, had taken a great interest in cryptology. He made the following :final comment on the Battle of Midway, a comment that is impressive in its guarded revelations and in its restraint: 28 

"One other lesson stands out. The American Intelligence system succeeded in penetrating the 

enemy's most closely guarded secrets well in advance of events. Thus Admiral Nimitz, albeit 

the weaker, was twice able to concentrate all the forces he had in sufficient strength at the right 

time and place. When the hour struck this proved decisive. The importance of secrecy and 

the consequences of leakage of information are here proclaimed." 

I 

It will probably seem to many of my listeners and readers that I have paid more tributes to 

the achievements of our Navy cryptanalysts in World War II than to those of their Army and 

Air Force opposite numbers. If I have done so, I can only say in extenuation that three factors 

are here involved. First, as regards my apparent overlooking of the contributions of the USAF, 

u The Hinge of Fate. Vol. IV. Boston: Houghton MifD.in Co., 1950, p. 252-3. 

172 
• 

... 

.. 

REF ID:A63860 

CONftBEN'f'IAL 

I need but remind you that it wasn't until after the war was all over that the Army Air Corps 

became autonomous; before then the technical achievements of cryptanalysts of that Corps 

were merged with those of the Army. Second, as a member of the Army's Signal Intelligence 

Service, and then the Army Security Agency during World War II, it is :fitting that somebody 

other than I blow the trumpets in celebration of our Army's cryptanalytic achievements. All 

I will say is that they were as important as those of our Navy, but for various reasons they have 

not received much publicity, which is just as well from the point of view of National Security. 

As a matter of fact, the publicity regarding our Navy's cryptologic successes comes very largely from former enemy officers and from the various official investigations into the attack on Pearl 

Harbor, and not from any U.S. Navy personnel. Third, there has been very little leakage with 

regard to Army's cryptanalytic successes except such as can also be traced back to those Pearl 

Harbor investigations. General Eisenhower's Crusa.de in Europe has not one word to say on 

the subjects of signal intelligence, cryptanalysis, codes, ciphers, or signal security, etc., although 

he does make a few rather caustic remarks about the failures and errors of his own intelligence 

staff. General Bradley's book is equally reticent on these subjects but I cannot refrain from 

quoting one rather amusing episode having to do with COMSEC: 

To identify hills, road junctions, and towns without our giving our plans away in the event 

of an enemy tap on the wire, I had key features numbered on my war map and gave copies of 

those numbers to the division commanders. It was a makeshift private code, lax enough to 

cause Dickson [Bradley's G-2] to worry over the security of our plans. 

One morning when I called Major General Terry Allen, he referred to an obscure crossroad 

by its number in this private code. 

"Just a minute, Terry," I said. "I can't find that number on my map." 

"Well, listen carefully, Brad," he said. "The enemy may be listening in. I'll say the name 

of the place as fast as I can." 

Dickson overheard this conversation and threw up his hands. "Security wouldn't be much of 

a problem," he said, "if only there were fewer generals in the army." 

General Hap Arnold's book I've mentioned before and have taken one extract from it. 

There are several others I might have used, but they are not too significant in revelations. 

One volume of the history of the U.S. Army in World War II, entitled "The Signal Corps" 

contains a few references to the achievements of the Signal Intelligence Service, but these, too, 

are not very illuminating. In only one book by a former U.S. Army Officer, Col. Robert S. 

Allen, entitled Lucky Forward: The His"tory of Patron's Third Army, 24 do I :find a specific reference to the help the SIS gave Patton. In telling about Patton's signal officer, Colonel Hammond, Allen writes: 

"One of his ace units was the SIS. A radio-interception agency, commanded by Major Charles 

Flint, a young, trigger-smart expert, it worked closely with G-2 on a dual mission: maintaining 

a vigilant security check on friendly communications and intercepting enemy messages. The 

unit performed outstandingly in both fields. 

Its reports plugged up an unwitting leak from a Mechanized Cavalry source, capable of revealing important troop-movement information to the enemy. And at a critical period in the 

Battle of Bastogne, the unit broke a German coded message that enabled heavy losses to be infilcted upon the redoubtable 5 Para Division. The SIS was particularly fruitful in breakthroughs 

and ftuid situations when the enemy was on the run and had to use radio." 

The foregoing extract is, of course, far from spectacular. Indeed, I imagine that it will 

hardly bring forth more than a polite yawn from many members of an audience that has already learned about the sensational revelations made during the various Pearl Harbor investigations and about those (amous letters that General Marshall wrote to Governor Dewey. 

But there remains this much more to be said: the achievements of our Army's cryptologic 

units both in Washington and in the :field, as well as certain still undisclosed top secret sue24 New York: The Vanguard Press, Inc., 1957, p. 56. The author makes some quite caustic comments 

about the failure of the intelligence staffs to make use of the intelligence they were furnished. They are worth 

reading. 

173 OONPIBB~Ala 
REF ID:A63860 

OO:NFIBEN'Hl .. Ea 

cesses of our Navy's units ashore and afloat, are locked away in archives where they will probably remain for a long, long time. More than this I am not at liberty to tell you in this 

lecture. 

With this statement I bring this series to a rather undramatic but I hope meaningful close. 

I will wind it up by paraphrasing the last sentence of the T nt.roduct.ion to that important book 

The Battle of Midway from which I have quoted at some length. The Introduction was written 

by Admiral Nobutake Kondo, the senior living commander of the fonner Imperial Navy, who 

participated in that battle: I close this series with the hope that my lectures will serve as 

material for criticism and reflection. 

174 
REF ID:A63860 

GO:HFH>BN'ffAL 

APPENDIX I 

From Time Magazine, 17 December 1945 

MAGIC WAS THE WORD FOR IT 

U.S. citizens discovered last week that perhaps their most potent secret weapon of World 

War II was not radar, not the VT fuse, not the atom bomb-but a harmless little machine 

which cryptographers painstakingly constructed in a hidden room at Fort Washington. 

With this machine, built after years of trial and error, of inference and deduction, cryptographers had duplicated the decoding devices used in Tokyo. Testimony before the Pearl 

Harbor Committee had already shown that the machine-known in Army code as "Magic"-

was in use long before Dec. 7, 1941, had given ample warning of the Jap's sneak attack-if 

only U. S. brass hats had been smart enough to realize it (Time Dec. 10). Now General 

Marshall continued the story of "Magic's" magic. It had: 

Enabled a relatively small U.S. force to intercept a Jap invasion fleet, win a decisive victory in the Battle of the Coral Sea, thus saving Australia and New Zealand. 

Given the U.S. full advance information on the size of the Jap forces advancing on Midway, enabled the Navy to concentrate ships which otherwise might have been 3,000 miles 

away, thus set up an ambush which proved to be the turning-point victory of the Pacific war. 

Directed U.S. submarines unerringly to the sea lanes where Japanese convoys would be 

passing. 

By decoding messages from Japan's Ambassador Oshima in Berlin, often reporting interviews with Hitler, given our forces invaluable information on German war plans. 

UNEASY SECRET 

So priceless a possession was Magic that the U.S. high command lived in constant fear that 

the Japs would discover the secret, change their code machinery, force U.S. cryptographers to 

start all over again. 

General Marshall had a long series of bad moments after U.S. :flyers, showing a suspicious 

amount of foresight, shot down Admiral Y amamoto's plane at Bougainville in 1943. Gossip 

rustled through the Pacific and into Washington cocktail parties; General Marshall got to the 

point of asking the FBI to find an officer "who could be made an example of." (The FBI, 

fearful of looking like a Gestapo, refused.) 

Once a decoder was caught in Boston trying to sell the secret. Once, well-meaning agents 

of the Office of Strategic Services ransacked the Japanese Embassy in Lisbon, whereupon the 

Japs adopted a new code for military attaches. This code remained unbroken more than a 

year later. 1 The worst scare of all came during the 1944 presidential campaign, when George 

Marshall heard that Thomas E. Dewey knew the secret and might refer to it in speeches (see 

below). 

Yet for all these fears, the Japs never discovered that the U.S. was decoding their messages. 

Even after the surrender the Army still used Magic as a guide to occupation moves: though 

it had once been planned to send a whole army into Korea, Magic showed that a single regiment would be enough. 

SECRET KEPT 

The letter, on stationery of the Chief of Staff's Office, bore a bold heading: TOP SECRET. 

FOR MR. DEWEY'S EYES ONLY. Candidate Thomas E. Dewey, his curiosity piqued, 

read rapidly through the :first two paragraphs: 

I am writing you without f:he knowledge of any other person except Admiral King (who concurs) 

because we are approaching a grave dilemma in f:he political reactions of Congress regarding Pearl 

Harbor. 

1 While I have no recollection of the Boston business, I shall never forget the Lisbon incident.-W.F.F. 

175 
REF ID:A63860 

GO:NFIBEN'l'l!a:l:a 

What I have to tell you below is of such a highly secret nature that I feel compelled t,o ask you 

either t,o accept it on the basis of your not communicating its contents to any other person and returning this letter or not reading any further and returning the letter f,o the bearer. 

Tom Dewey looked up from the typewritten page. As he did, the word crypwgraph, a few 

paragraphs below, flashed into his vision like a red traffic light. He made his decision quickly, 

folded the letter, handed it back. Colonel Carter W. Clarke tin mufti), who had flown from 

Washington to Tulsa to catch up with Tom Dewey's campaign, went back, his mission uncompleted. 

YOU HAVE MY WORD 

It was September 1944. The campaign train rolled up through the Midwest, returned to 

Albany. A few days later, Tom Dewey received another visit from Colonel Clarke. 2 

The Colonel, again in civilian clothes, handed over another letter from General Marshall. 

The General had changed his mind somewhat: 

I am quite willing t,o have you read what comes hereafter with the understanding that you are 

bound not t,o communicate t,o any other person any portions on which you do not now have or later 

receive factual knowledge from some other source than myself. . . . You have my word that neither 

the Secre'ta.ry of War nor the President has any intimation whatsoever that such a letter has been 

addressed t,o you . ... 

THE LOCKED FILE 

This time Tom Dewey read on. As he turned the pages, he became the :first man outside 

the high command to know the full story of "Magic" and what it was accomplishing in the 

war against the Japs (see above). The letter closed with a plea: 

I am presenting this matter t,o you, for your secret information, in the hope that you will see 

your way clear t,o avoid the tragic results with whiCh we are now threatened in the present political 

campaign. 

Tom Dewey locked the letter in his files, went back to his electioneering. Though he had 

known before that the U.S. had cracked the Jap code, had suspected that this information 

cast grave doubts on Franklin Roosevelt's role before Pearl Harbor, he held his tongue. The 

War Department's most valuable secret was kept out of the campaign. 

l\IEETING AT A FUl\"ERAL 

Recounting this story at the Pearl Harbor hearing last week, General Marshall recalled that 

he and Tom Dewey had never discussed the matter in person until they met at Franklin Roosevelt's funeral last April: "I asked Mr. Dewey to come with me to the War Department and 

I showed him current Magic showing Japanese movements. His attitude was friendly and 

gracious." 

Had Marshall ever told Franklin Roosevelt of the letters to Dewey? Said Marshall: "The 

President died without knowing of it." 

SECRET LOST 

The Pearl Harbor Committee blithely tossed away one still-secret U.S. weapon. George 

Marshall's letters to Governor Dewey (see above) mentioned that the U.S., with the help of the 

British, had decoded German as well as Japanese messages. George Marshall begged the 

Committee to cut out these references. The Committee refused. 

Publication of the letters thus gave the Germans their :first knowledge that their code had 

been broken. It was also a breach of diplomatic confidence with the British, who had let the 

U.S. in on the secret on the understanding that it would be kept. 

1 "A few days later ... " But note that the :first letter is dated 25 September 1944, the second, 27 September. 

It is possible that Colonel Clarke was unable to deliver the letter, but my recollection is that he did deliver 

it the very next day.-W.F.F. 

OONFIBBN'l'IAL 176 
• 

REF ID:A63860 

OO:NPIBBN'f'IAL 

ANATOMY OF CONFUSION 

Up to the witness stand stepped Lieut. General Leonard T. Gerow, chief of the Army's War 

Plans Division in 1941, to accept full blame for one of Pearl Harbor's most egregious errors. 

On Nov. 27, a sharp warning of impending hostilities had gone out from General Marshall to 

Lieut. General Walter C. Short in Hawaii. On Nov. 28, General Short replied that he had 

ordered an alert againsL saboLage-which was like saying he had a butterfly net ready for a 

tiger. Yet his reply was never challenged by Washington. Why? 

Explained General Gerow: he thought the Short message was an answer to other communications. Said he: "If there is any responsibility in the War Department for failure ... I 

accept that responsibility." 

Then up stepped General Marshall himself to take part of the blame. He didn't recall 

seeing the Short message; he should have. "That was my opportunity to intervene and I 

didn't take it," he confessed. "Just why, I do not know." 

FOURTEEN POINTS 

The week's testimony also shed light on the warning that came too late-the message Walter 

Short received on Dec. 7 at 2:58 p.m. Hawaiian time informing him that the Japs were on 

the way. 

On the night of Dec. 6, Major General Sherman Miles, Chief of Intelligence, received from 

"Magic" decoders the :first thirteen points of the strongly worded, :final Jap diplomatic note 

being sent from Tokyo to its envoys in Washington. Next morning, some time between 7 and 

8 o'clock, an assistant telephoned that he had "important" information. General Miles 

reached his office at 9 o'clock. 

General Marshall had risen early, breakfasted at 8, looked over the Sunday papers, gone 

out for a horseback ride. (He usually rode for 50 Ininutes.) He was in the shower when an 

urgent message arrived by telephone from General Miles' assistant. He :finished his bath, 

dressed quickly and went straight to the War Department. The time: 11:25 a.m. 

\VllO'S CONFUSED? 

A hastily gathered staff meeting decided that the Jap note meant war, that a warning should 

go immediately to Hawaii, the Philippines, the West Coast, the Canal. General Marshall 

called Admiral Harold R. ("Betty") Stark, then Chief of Naval Operations. "Betty" Stark 

thought by some obscure reasoning that further warnings would "only confuse" :field commanders. 

General Marshall wrote out a warning anyway, called Adiniral Stark again to read it. Stark 

decided on second thought that the warning might as well go to Navy commanders as well. 

General Marshall sent it on to the Signal Corps which proinised, according to General Miles, 

that it would be delivered in 20 minutes. It was then 11:50 a.m.; the attack was one hour 

and ten minutes away. 

Instead of 20 Ininutes, the Signal Corps took eight hours and 28 minutes to get the message 

to Short (by commercial cable instead of Army radio). Nobody had bothered to check up 

on the Signal Corps; the General Staff took for granted that the message was going full speed 

ahead. 

Why hadn't General Marshall used the telephone? His explanation: he knew that many 

phone calls-including transatlantic talks between Franklin Roosevelt and Winston Churchillhad been tapped; he feared that the Japs would intercept his call and label it an "overt act." 

Anyway, he said, even if he had phoned he would :first have called the Philippines, where he 

thought the real danger lay. 

Said George Marshall: "We thought Hawaii was the most improbable [target] of all .... 

I was inclined to feel the hazards were too great and they would not risk it." 

177 
CONflBHN'f'IAL 

REF ID:A63860 

APPENDIX II 

The Letters from General Marshall t,o 

Governor Dewey, 25 and 27 September 1944 

The Marshall-Dewey correspondence is so important in cryptologic history that I feel that 

the whole of it should be included even in this brief history. When the letter was written, it 

was, of course, TOP SECRET and it was only under great pressure from certain members of 

the Joint Congressional Committee that General Marshall revealed its contents. 3 Thus, it 

came into the public domain not only on the very day that General Marshall was forced to 

place it in evidence-its publication caused a great sensation in the newspapers-but also when 

the 40 volumes of the Hearings of that Committee were published and put on sale by the 

Superintendent of Documents of the Government Printing Office. The disclosure of the contents of the Marshall-Dewey correspondence was indeed such a sensation that Life magazine 

printed the whole of it in its issue of 17 December 1945, with the following introduction: 

MARSHALL-DEWEY LETTERS 

General Told Candidate We Had Broken Jap Code 

During the 1944 election campaign General George C. Marshall wrote two letters to Republican Candidate Thomas E. Dewey, telling him that Army cryptographers had broken the Japanese "ultra" code. This fact was first revealed in a story by Life Editor, John Chamberlain, 

which appeared in Life, Sept. 24. Marshall's purpose, Chamberlain wrote, was to forestall 

Dewey's revelation of that fact in a possible attack on the Roosevelt administration's Japanese 

policy before Pearl Harbor. The actual text of the letters remained secret until last week, 

when General Marshall appeared before the Congressional Committee investigating Pearl Harbor and made the letters public. They appear below. 

When he had :finished reading the first two paragraphs of the first letter, Governor Dewey 

stopped because, as the Chamberlain article reported, "the letter might possibly contain material which had already come from other sources, and that anyway, a candidate for President 

was in no position to make blind promises." General Marshall sent the letter back again with 

an introduction which relieved the governor of binding conditions. This time Dewey read the 

letter and after much thought and discussion decided not to make use during the campaign of 

any information he previously had. 

First Letter 

TOP SECRET 

(FOR MR. DEWEY'S EYES ONLY) 

25 September 1944 

My Dear Governor: 

I am writing you without the knowledge of any other person except Admiral King (who concurs) because we are approaching a grave dilemma in the political reactions of Congress regarding Pearl Harbor. 

What I have to tell you below is of such a highly secret nature that I feel compelled to ask 

you either to accept it on the basis of your not communicating its contents to any other person and 

returning the letter or not reading any further and returning the letter to the bearer. 

I should have preferred to talk to you in person but I could not devise a method that would 

not be subject to press and radio reactions as to why the Chief of Staff of the Army would be 

seeking an interview with you at this particular moment. Therefore, I have turned to the method of this letter, to be delivered by hand to you by Colonel Carter Clarke, who incidentally has 

charge of the most secret documents of the War and Navy Departments. 

In brief, the military dilemma resulting from Congressional political battles of the political 

campaign is this: 

1 So far as I am aware it has neither been ascertained nor disclosed, if known, who gave Governor Dewey 

the information. But it is a fact that as a patriotic citizen, he acceded to General Marshall's request-he 

made no use whatever of the vital secret information during the campaign or after it. Time's account specifically states that Dewey "held his tongue." The War Department's most valuable secret was kept out of 

the campaign." I know this to be true.-W.F.F. 

178 
• 

.. 

REF ID:A63860 

CONPIBBN'ffA:L 

The most vital evidence in the Pearl Harbor matter consists of our intercepts of the Japanese 

diplomatic communications. Over a period of years our cryptograph people analyzed the character of the machine the Japanese were using for encoding their diplomatic messages. Based 

on this, a corresponding machine was built by us which deciphers their messages. 

Therefore, we possessed a wealth of information regarding their moves in the Pacific, which 

in turn was furnished the State Department-rather than, as is popularly supposed, the State 

Department providing us with information-but which unfortunately made no reference whatever to intentions toward Hawaii until the last message before Dec. 7, which did not reach our 

hands until the following day, Dec. 8. 

Now the point to the present dilemma is that we have gone ahead with this business of deciphering their codes until we possess other codes, German as well as Japanese, but our main 

basis of information regarding Hitler's intentions in Europe is obtained from Baron Oshima's 

message from Berlin reporting his interviews with Hitler and other officials to the Japanese 

Government. These are still in the codes involved in the Pearl Harbor events. 

To explain further the critical nature of this setup which would be wiped out almost in an 

instant if the least suspicion were aroused regarding it, the Battle of the Coral Sea was based on 

deciphered messages and therefore our few ships were in the right place at the right time. Further, we were able to concentrate our limited forces to meet their advances on Midway when 

otherwise we almost certainly would have been some 3,000 miles out of place. 4 

We had full information of the strength of their forces in that advance and also of the smaller 

force directed against the Aleutians which finally landed troops on Attu and Kiska. 

Operations in the Pacific are largely guided by the information we obtain of Japanese deployments. We know their strength in various garrisons, the rations and other stores continuing 

available to them and what is of vast importance, we check their :8.eet movements and the movements of their convoys. 

The heavy losses reported from time to time which they sustain by reason of our submarine 

action largely results from the fact that we know the sailing dates and the routes of their convoys and can notify our submarines to lie in wait at the proper point. 

The current raids by Admiral Halsey's carrier forces on Japanese shipping in Manila Bay and 

elsewhere were largely based in timing on the known movements on Japanese convoys, two of 

which were caught, as anticipated, in his destructive attacks. 

You will understand from the foregoing the utter tragic consequences if the present political 

debates regarding Pearl Harbor disclose to the enemy, German or Jap, any suspicion of the vital 

sources of information we now possess . 

The Robert's report on Pearl Harbor had to have withdrawn from it all reference to this highly 

secret matter, therefore in portions it necessarily appeared incomplete. The same reason which 

dictated that course is even more important today because our sources have been greatly elaborated. 

As a further example of the delicacy of the situation, some of Donovan's people (the OSS), 

without telling us, instituted a secret search of the Japanese Embassy offices in Portugal. As a 

result the entire military attache Japanese code all over the world was changed, and though this 

occurred over a year ago, we have not yet been able to break the new code and have thus lost 

this invaluable information source, particularly regarding the European situation. 

A recent speech in Congress by Representative Harness would clearly suggest to the Japanese 

that we have been reading their codes though Mr. Harness and the American public would probably not draw any such conclusion. 

The conduct of General Eisenhower's campaign and of all operations in the Pacific are closely 

related in conception and timing to the information we secretly obtain through these intercepted 

codes. They contribute greatly to the victory and tremendously to the saving of American 

lives, both in the conduct of current operations and in looking toward the early termination of 

the war. 

I am presenting this matter to you, for your secret information, in the hope that you will see 

your way clear to avoid the tragic results with which we are now threatened in the present political campaign. I might add that the recent action of Congress in requiring Army and Navy 

investigations for action before certain dates has compelled me to bring back the corps commander, General Gerow, whose troops are fighting at Trier, to testify here while the Germans 

are counterattacking his forces there. This, however, is a very minor matter compared to the 

loss of our code information.1 

4 In regard to this and the succeeding four paragraphs, see my comment below (p. 122). 

6 The last two sentences in this paragraph were omitted from the Second Letter. See footnote'. 

179 CON-PIBl!lN'ffAL 
REF ID:A63860 

Please return this letter by bearer. I will hold it in my secret file subject to your reference 

should you so desire. 

Second Letter 

'I'OP SECRET 

(FOR MR. DEWEY'S EYES ONLY) 

My Dear Governor: 

Faithfully yours, 

G. C. Marshall 

27 September 1944 

Colonel Clarke, my messenger to you of yesterday, Sept. 26, has reported the result of his delivery of my letter dated Sept. 25. As I understand him you (A) were unwilling to commit 

yourself to any agreement regarding "not communicating its contents to any other person" in 

view of the fact that you felt you already knew certain of the things probably already referred 

to in the letter, as suggested to you by seeing the word "cryptograph," and (B) you could not 

feel that such a letter as this to a Presidential candidate could have been addressed to you by 

an officer in my position without the knowledge of the President. 

As to (A) above I am quite willing to have you read what comes hereafter with the understanding that you are bound not to communicate to any other person any portions on which you 

do not now have or later receive factual knowledge from some other source than myself. As to 

(B) above you have my word that neither the Secretary of War nor the President has any intimation whatsoever that such a letter has been addressed to you or that the preparation or sending of such a communication was being considered. 

I assure you that the only persons who saw or know of the existence of either this letter or my 

letter to you dated Sept. 25 are Admiral King, seven key officers responsible for security of military communications, and my secretary who typed these letters. 

I am trying my best to make plain to you that this letter is being addressed to you solely on 

my initiative, Admiral King having been consulted only after the letter was drafted, and I am 

persisting in the matter because the military hazards involved are so serious that I feel some 

action is necessary to protect the interests of our armed forces. 

(The second letter then repeated substantially the text of the first letter except for the first two para.-

graphs). 

Life failed to note that the last two sentences in the penultimate paragraph of the "First 

Letter" were omitted from that paragraph in the "Second Letter," but there is no explanation 

for the om.ission. 6 Perhaps it was simply for the sake of brevity, but this seems improbable. 

In my first lecture I called attention to the fact that the account given in the Time article 

gives credit to Army cryptanalysts for providing the secret communication intelligence "which 

enabled our Navy to win such spectacular battles as those of the Coral Sea and Midway, and 

to waylay Japanese convoys," whereas the credit for the communication intelligence which 

enabled our Navy to win these battles was produced by Navy cryptanalysts. One cannot 

blame the editors of Time for making such a bad error because the source of the error can be 

traced directly io General Marshall's letter itself. Several years ago I asked my friend Colonel 

Clarke, who, you will recall, carried General Marshall's letter to Governor Dewey, how such 

an error had crept into General Marshall's letter and was told that the letter which had been 

prepared for General Marshall's signature did not meet with the General's wholehearted approval and that the General himself had modified it. Perhaps that is how the error to which 

I have referred crept into it. One could hardly expect General Marshall to be entirely familiar with the technical cryptanalytic details involved in what he wanted to tell Governor Dewey, 

nor should one criticize him for not being able, in his very busy days and under very heavy 

pressure of events, to bear in mind or even to know about the differences between the enemy 

systems worked upon by the respective and separate Army and Navy cryptanalytic organizations. It is of course possible, indeed it may be, that in the cases of certain important naval 

operations valuable COMINT caine from messages read by Army cryptanalysts, and this may 

0 The sentence beginning "I might add . . . " and the one beginning "This, however is . . ." were omitted. 

180 
• 

.. 

REF ID:A63860 

be what confused General Marshall in implying that all the credit belonged to them because 

of their solution of the Japanese highest-level diplomatic cryptosyst.ems, the one that used the 

so called "Purple Code," which wasn't a "code" but a cipher machine. 

Since the period during which the disclosures of the Joint Congressional Investigation were 

made, disclosures which were disastrous so far as the important accomplishments of the two 

services, before and after the Pearl Harbor attack, in the field of communications intelligence, 

much has been written and is now in the public domain regarding those accomplishments, 

but fortunately no technical details of significance have been disclosed . 

181 
60NPIBRN'FIAL 

REF ID:A63860 

BIOGRAPmCAL SKETCH 

WILLIAM F. FRIEDMAN-B.S. (genetics), 

Cornell University, 1914; Research Fellow, New York 

State Experiment Station, Geneva, N.Y., 1914; Graduate Student and Instructor in Genetics, Cornell University, 1914-1915; Director, Dept. of Genetics, 

Riverbank Laboratories, Geneva, Ill., 1915-1916; 

Director, Depts. of Ciphers and Genetics, Riverbank 

Laboratories, 1916-1918; 1st Lt., N.A., serving in 

Code and Cipher Solving Section, G2, GHQ AEF, 

Chaumont, France, 1918-1919 (retired as Lt. Col., 

USAR, 1951); Director, Dept. of Ciphers, Riverbank 

Laboratories, 1919-1920; Cryptographer, OCSigO, 

Washington, D.C., 1921; Cryptanalyst, Wsr Department, 1922-1947; Director, Communications Research, Army Security Agency, 1947-1949; Cryptologic Consultant, Army Security Agency, 1949; Research Consultant, Armed Forces Security Agency, 

1949-1951; Research Consultant, National Security 

Agency, 1951-1954; Special Assistant to the Director, 

NSA, 1954-1955 (retirement); Member, NSA Scientific Advisory Board, 1954-; Special Consultant, 

National Security Agency, 1955-. 

For his many contributions to the security of his 

country, he has received the War Department Medal 

for Exceptional Civilian Service (1944), the Presidential Medal for Merit (1946), the Presidential National 

Security Medal (1955), and a special congressional award of $100,000 for inventions and patents in the :field 

of cryptology (1956). For their contributions to literature, he and Mrs. Friedman received the Fifth Annual 

Shakespeare Award in 1958 from the American Shakespeare Festival Theater and Academy for their book 

"The Shakespearean Ciphers Examined." 

Mr. Friedman is a member of Sigma Xi, the Cosmos Club, the U.S. Naval Institute, and the Shakespeare 

Association of America. He is listed in Who's Who in America, and in American Men of Science. 

Author of many classified books and brochures, technical treatises and articles on cryptologic subjects; 

articles in the Signal Corps Bulletin (1925-1940); Riverbank Publications on Cryptology (1918-1922), the 

more important of which are "Several Machine Ciphers and their Solution," "The Index of Coincidence and 

Its Applications to Cryptography," and "Applications of the Science of Statistics to Cryptography." Technical papers and reports published by the Office of the Chief Signal Officer and by the Signal Intelligence 

Service (1935-1945), among which may be mentioned "The Principles of Indirect Symmetry of Position in 

Secondary Alphabets and their Application in the Solution of Polyalphabetic Substitution Ciphers," "American Army Field Codes in the American Expeditionary Forces in the First World War," "Field Codes used 

by the German Army during the World Wsr," and "Analysis of a Mechanico-Electrical Cryptograph." Encyclopaedia Britannica article on "Codes and Ciphers (Cryptology)," 1927 (revised 1954). "Jacques Casanova, Cryptologist," in Casanova Gleanings, Nice, France, 1961. Co-author with his wife, Elizebeth Smith 

Friedman, of the "Shakespearean Ciphers Examined," 1957; "Acrostics, Anagrams and Chaucer," Phiwlogical 

Qua.rt.erly, 1959; "The Cryptologist Looks at Shakespeare" (Folger Shakespeare Literary Prize), 1955. 

182 M4(M6)-Feb 63-83--5386 
REF ID:A63860 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED 

• 

CONFIDENTIAL 

MODIFIED HANDLING AUTHORIZED