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COMMUNICATIONS INI'ELLIGENCE 

Outline of Present~tion by Mr. William F. Friedman, Consultant, Armed 

Forces Security Agency, at the Second Annual Communications Security Officers' 

Conference to be held at Brooks Air Force Base, 3-7 March 1952. 

I. Introduction 

A. Appreciation of opportunity to address the Conference 

1. Impression that last year's conference, the first of its 

kind in the history of communication security in the 

Armed Forces of the u. S., showed considerable initiative, 

forward-looking viewpoints, and excellent understanding 

of the COMSEC field. 

2. Above impression stengthened by excellent tone of this 

year's conference. 

J. Much benefit .to be obtained from the mutual exchange of 

ideas. 

&• Particular appreciation of opportunity to address this Conference 

on communications intelligence 

1. Relationship of communications security (COMSEC) and cornmunica .. tions intelligence (COMINT) - close 

ILLUSTRATI.ON: During second World War the President, and other 

high-ranking u. S. Government officials journeyed 

at great distances without "accident. 11 On the · other hand, the plane carrying Japanese Commanderin-Chief, Yamamoto, on an inspection trip in 

April 1943 was shot down by U. S. planes. 

Yamamoto 1 s death was no "accident." U. s. Navy 

communications were reading Japanese messages and 

knew the schedule, escort, etc., for the Japanese 

Commander-in-Chief. Our officials travelled in 

safety because our communications were secure; 

the Japanese Commaiiier-in~chief journeyed in 

peril because his communications were insecure. 

They were vulnerable tO our COMINT. 

C. Importance of COMINT 

1. Has not always been appreciated 

ILLUSTRATION: Story of Semiramis, the Persian queen, who had 

inscribed upon her tomb a message that if the 

cryptogram engr?-ved thereon could be solved it 

would lead to riches beyond all dreams of avarice. 

Many hundred years later the message was solved 

Declassified and approved for release by NSA on 11-22-2013 pursuant to E .0. 1352a 

0 
• 

by an earnest student, only to find within the 

tomb a message in plain text that had he learned 

something more useful than the art of deciphering, 

he would not be in need of money. 

2. In World War II was recognized as a vital military weapon. 

ILLUSTRATION: Paragraph from Time Magazine of December 17 ,,' 1945 

revealing the use of a cryptanalytic machine in 

World War II which deciphered Japanese diplomatic 

messages. 

II. Communication Intelligence: History and -Development 

A. General remarks 

1. Definition: all intelligence derived from the study of radio 

transmissions and other communications. 

2. Objectives 

a. To provide authentic information for policy makers, and 

appraise them of realities of the international situation, 

of the war making capacilities and vulnerabilities of 

foreign countries, an:l of the intentions of those countries 

with.respect to war. 

b. To eliminate the element of surprise from an act of 

aggression by another country. 

c. To provide unique information essential to the successful 

prosecution, and vital to the shortening, of the period 

of hostilities;. 

3. General development 

Communications intelligence, which is based on the science of 

cryptanalysis, has a long history inextricably bound up with 

the history of cryptography, which is the basis of communications security. 

4. Limitations of discussion 

a. Information on history and development of foreign countries 

is sparse. 

b. Security considerations preclude; 

(1) Comparison of foreign an:l U. S. systems er successes 

(2) Discussion of current U. s. developments. 

2 

s~~~~J 
c. Personal experience limits discussion mainly to Army's 

cryptodevel~pments. 

B. History of Cryptology, Illustrated 

1. Biblical examples 

a. 

b. 

Jeremiah 25:26 and 51:41: Shlhakh a cipher for Babylon. ~ 

Daniel 5:25-29: interpretation of MENE, MENE, TEKEL, 

UPHARSIN. 

2. Examples from classical antiquity 

(1) 

a. Scytale used by the Lacedaemonians to send messages to (2) 

field comrna.rders. 

b. Simple substitution used by Julius Caesar. 

c. Shorthand used by Tiro, the amanuensis of Cicero. 

3. Ciphers of the 15th, 16th and 17th centuries. 

a. Beginnings of modern cryptogrB:phy found in Venice and the 

Papal States - 1400. 

Knowledge of basic weakness of monoalphabetic substitutions recognized and corrected by having high-frequency 

letters represented by more than a single character. 

b. Earliest tract on cryptography and cryptanalysis written 

in 1474 by the Neopolitan, Simion Simonetta. 

c. First extensive treatise on cryptography '\'ll'itten by the 

German abbot, Trithemius, in l.531. 

(1) Books burned as having been vn .. i tten in league with 

the Devil. 

(2) Oath of secrecy still pertinent. 

d. Ciphers used in diplomacy 

(4.10) 

(151) 

(l) Cipher alphabet used by Mary, Que~n of Scots, 

circa 1545. 

(2) Tables of the Italian cryptographer, Porta. 

(3.5 (3.5 & 6.1) 

(a) Greatest of early cryptographers · (b) Inventor of the camera obscura 

(c) One of earliest cr,yptanalysts to solve a 

system of keyed substitution. 

3 
~ REF ID:A66405 

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(3) Porta•s Table· - found among state papers of Queen 

Elizabeth, used to communicate with the English 

Ambassador in s:Pain. 

(4) Vigenere Square - not invented by Vigenere but 

reproduced by him. 

(5) -Francois Vieta, fourxier of modern algebra. In 

1589 as Privy Counselor Vieta solved the Spanish 

cipher system used by Phillip II of Spain, 

thereby being accused of sorcery. 

(6) Sliding-card cipher. Facsimile of one used later 

in reign of Queen Elizabeth. 

(7) "Two-word or two-alphabet" square cipher involving 

coordinates. 

Used in time of Charles I (1627) to communicate 

with ambassad·or s in France an:i Fl anders. 

4. Ciphers of the American Revolution 

a. Ciphers used by the British and the Americans were almost 

identical, many of the British messages being solved by 

an American, a "cipher expert to Congress." 

b. Examples of use of cipher 

. (1) Jeffersonian syllabary, constructed on the two-part 

principle. 

(2) CipherS". used by Benedict Arnold in communication 

with British. 

5. Marked advances - 19th century 

a. Solution of Egyptian hieroglyphics by a Frenchman, 

Jean Francois Champollion, about 1821 represents 

greatest linguistic achievement of 19th century. 

(1) Solution bssed on tri-lingual inscription on 

Rosetta Stone. 

(2) Examples of cartouches from the Stone. 

(3) Certain writings of the Egyptians cryptographic 

in character. 

b. Literary interest in cryptography exemplified by tales 

of Edgar Al~n Poe { '~ 1-1.. ·n .. e _C-o \~ '5 ~· 

(6.1) 

(5.1) 

(5.2) 

(3. 7) 

(3.8) 

(6.2) 

(6.8) 

(4.0) 

(4.1) 

(4.2) 

(4.6) 
c. Civil war 

(1) Confederate cipher device based on pr~ciples of 

the Vigenere square. 

(2) Examples of route cipher used by Federal Anny. 

(a) Message from Lincoln to Burnside. 

(b) Message to General Grant. 

d. Franco-Prussian War 

Example of micro-photography used by French in 

seige of Paris. 

6. Decline in cryptography 1864-1917 

a. Military codes based on commercial codes. 

Slater's code of 1906, "Telegraphic Code to Insure 

Secrecy in the Transmission of Telegrams" based almost 

word for word on "Telegraphic Code to Insure Secrecy 

in the Transmission of Telegrams," by J. F. Gregory 

published in 1885. 

b. Chief Signal Officer personally prepared suitable code 

in 1899. 

c. "Cipher of the War Department" 

First published in 1902 by the Adjutant General; 

revised in 1906. 

d. War Department Telegraph Cede 

(1) Printed in 1915 by a commercial firm in Cleveland. 

(2) Only code when U. S. entered war in 1917. 

(3) Informed by British that the code was not saf'e to 

use. 

7. World War I 

a. New era of communications and cryptology 

(1) Hertz•s discovery of so-called Hertzian waves. 

(2) Marconi's demonstration of signalling by wireless. 

b. Tactical systems used by belligerents. 

5 

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(7) 

(8) 

(10) 

(128) 

(214) 

(216) 
REF ID:A66405 

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(1) Cipher system used by Russians based on Vigenere 

square. 

(2) Front-line system used by French a transposition 

system with. columnar key. 

(3) System used by Italian army also a variation of 

Vigenere square. 

(4) System used by Germans: the ADFGVX cipher. 

Early AEF examples of traffic analysis and 

traffic intelligence based on intercept and 

solution of .ADFGVX sys terns • 

(5) Playfair system used by British and Americans. 

(a) Invented not by Loni Playfair but by Sir 

Charles Wheatstone. 

(b) Description of encipherment. 

(c) Early description of solution published in 

1914 by J, o. Mauborgne, later Major General 

and Chief Signal Officer. · 

(6) Proposed cipher device of British Army. 

c. Codes and code systems of World War I. 

(1) Prior to World War I were thought impractical for 

tactical use. 

Limited to commercial or diplomatic usage. 

(2) Germans first used field codes in 1916; soon 

followed by Allies. 

• (a) Early AEF codes like the "Baseball Code" of 

the 52d Infantry Brigade inadequate, 

(b) Field codes of Allies later very good. 

d. Famous cryptograms of World War I. 

(1) Zimmermann message which brought the U. s. :hn on 

the side of England. 

(2)-Waberski telegram. 

(3) Sabotage messages connected with the Kingla:rrl 

fire and the Black Tom explosion. 

(4) Messages pertaining to the Hin,!l.u revolt incited 

by the Germans, 

- - --- /--- 6 

I"( ___ ; I - I ( ' - - - ' I j 

(11) 

(12) 

(13) 

(14) 

(15, 14.1) 

(23) 

(159) 

(20) 

(21) 

(19, 22) 

(28' 29) 

(25, 25.1) 

(127) 

(33) 
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(a) Messages solved by Friedman 

(b) Dramatic ending in court scene 

e. Cryptograms from peace time. 

(1) Oil scandal in President Harding's regime. 

(2) Rum-runners of Prohibition days. 

(3) Solution of messages for Secret Service. 

8. Cipher Devices 

a. Invention and introduction into wme usage of radio 

brought advances in cryptographic methods, particularly the invention of cryptographic devices and 

machines. 

b. Brief review of histocy of cipher devices. 

(1) Disc from book by Alberti, 1470 

(a) Patented in 1865 by Major Albert J. Myer 

then Chief Signal Officer 

(b) Used by U. S. Signal Corps from 1910 to 

1918. 

(c) Patented again in 1924. 

(2) Cipher device developed by British in World 

(38) 

07) 

(44.1) 

(45) 

(45.2) 

(45.4) 

War I arrl distributed on Western Front. (47) 

(a) Modeled on the Wheatstone cipher device 

(invented in 1870). (48) 

(b) Solved by Friedman at Riverbank Laboratories 

before it was actually in use. (157-Fabyan) 

(c) Comparison with Decius Wadsworth cipher 

device invent ed. in 1917. 

(3) Bazeries' "cipher cylinder11 

(49.1) 

(49.S, 49.4) 

Comparison with the device invented by 

Thomas Jefferson. 

(4) Same system invented indeperrlently in form of 

strips by Colonel Parker Hitt, U. s. Army. 

Solved by Friedman at Riverbank Laboratories. 

(50) 

(160.1, 160) 

(5) Cylindric pringiple adopted.4 by U. S. Army Signal Corps in 19ltl as the M-9 • (50.2) 

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(6) Adaptation of sliding strip form by U. s. Army 

as Cipher Device M-138. 

(7) AT&T Company Machine 

(a) Produced in 1918 as the first one-time tape 

cryptographic transmission machine. 

(b) Solved by Friedman at Riverbank Laboratories. 

(8) Hebern Cryptographic machines 

(a) Early machine with one wheel 

(b) Five-wheel machine produced in collaboration 

with Navy. 

1. Machine solved Py- Friedman before final 

contract was drawn. 

2. Hebern reduced to penury. 

(9) Foreign Cryptodevelopments 

· (a) Commercial Enigma built in Europe in early 

20 1 s arrl sold on commercial market until 

1933 when it was adapted for German 

military use. 

(b) Kryha, German machine built for commercial 

use and considered unsolvable, but in reality 

solved with ease. 

(c) Swedish machine B-21 of same period. 

(d) Joined to a Remington electric typewriter, 

this becomes a printing cipher machine. 

( e) Later modified to have the printing mechanism 

self-contained in the cryptograph - the 

Swedish 211. 

(10) Types of teletype cipher attachments. 

(50.8) 

(56) 

{71) 

(71.1) 

(72) 

(165) 

(57) (74.2) 

(54) 

(55) 

(58.1) 

(59) 

{65) 

(a) AT&T Company machine mentioned above in 8(8). 

(b) IT&T Company machine invented by Colonel Hitt 

after his retirement from the Army in 1925. (60, 64) 

(c) Automatic Electric Company of Chicago failed. 

(d) IBM Company-failed. 

(e). Successful crypto-attachment for teletype 

developed by U. S. Army in 1943. 

S~h~~ 

finally 
('' 

III. 

(11) U. S. Anny Cryptomachines 

(a) M-209 based on Swedish, invention in ~O)(c) 

above, mechcμ-iized in field. 

(b) Converter M-161 

{ c) Converter M-134A . 

(d) Converter M-134C (SIGABA/ECM) 

9. Cryptanalytic aids 

a. History of development 

{70.l, 70.2) 

(70.3) 

(171) 

{170.8) 

(173) 

(1) First ~ptanalytic aid developed by Fria:iman at 

Riverbank Laboratories in 1916. (131) 

~2) Use of IBM machinery after 1934. 

(3) Use of high-speed machinery. 

(4) Recent development of electronics cryptanalytic 

gadgetry. 

(134, 135) 

b. Advantage of machines is that they perform at a high rate 

of speed, accurately and without need for rest, relaxation 

etc., the processes which the human brain can perform at 

a much slower rate. 

c. Examples 

(1) Analogs for decipherment (139, 145, 144) 

(2) IBM Standard Tabulator for use in locating 

repetitions • (141) 

(3) Slide run unit for comparing messages. (138) \ 

{4) The "Camel" am the Camel Code Indicator. (14o,146) 

(5) The nAuto-scritcher" or llRcdin". (143) 

Conclusions 

A. Manner of employment of connnunications intelligence. , 

:i. Use in war to shorten hostilities. 

a. Revealed by Pearl Harbor investigations. 

9 

(.-~~ 1·-- ~~ ((~ ;-: : : : 
• 

b. Noted in letter of General Marshall to Governor Dewey, 

(1) Hitler 1 s intents in Europe known from messages of 

Japanese Ambassador in Berlin to his Government. 

(2) Battle of Coral Sea and Midway based on deciphered 

messages which ma.de concentration of our naval 

forces possible. 

(3) Operations in Pacific guided by deciphered messages. 

(4) Heavy losses to enemy convoys from submarine action. 

B. Succe'ssful COMINT requires large organization, 

1. World-wide intercept. 

2. Expeditious forwarding to processing center. 

3. Central pro~essing organization for concentration of highly · skilled personnel and specialized machinery. 

4. Evaluation, integration, collation. 

5. Transmission of intelligence to operational commanders. 

C. COMINT activities must be co-ordinated with tactical operations 

1. Field commanders must give adequate cover to operations based 

on information obtained from COMINT. 

a. Minor tactical success may result in loss of valuable 

intelligence from an enemy crypto system which has an 

area - or world-wide distribution, since the enemy may 

guess the source.of information. 

b, Destruction of enemy communication system or element 

thereof may result in loss of valuable COMINT. 

2. Conversely producers of COMINT. must be fully oriented on the 

current tactical situation. 

a. In order to give optimum coverage and to know where to 

place maximum effort. 

b, In order to give proper evaluation to the results. 

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