REF ID:A38365 

fWl.. 

All right, let's turn the lights out and ring the bell, I think there~ 

some absentees.~t!r~ 

Well, let's go on with the slides There are a couple of slides ~want to 

show I am going to talk a bit about the traffic analysis from our own point 

of view of communication security This is meant to illustrate the important 

intelligence that is derived by traffic analysis by watching the flow mix and 

ebb of traffic and this one shows convoys across the Atlantic from Hampton Roads 

and Algiers The chart shows the daily breakdown by security classification of 

the traffic from Hampton Roads, Port of Embarkation, to Algiers, North Africa 

for the month of April 1944 Three definite peaks in traffic volume are 

evident, each of which indicates a convoy movement from Hampton Roads to Algiers 

The approximate size of the movement is Judged f~om the total messages in groups 

and peak periods while the destination and route are given away by addressee 

callsigns in the messages Close inspection will show that the first traffic 

search began on 4 April, the second on 13 April and the last on 22 April Experience 

circuit the 

has shown that these traffic peaks appear on the/day or two following the actual 

convoy sailing date The convoy movements are therefore called on the 2nd, ll.th 

and 2~th of April Furthermore, the traffic study shows definitely the proportions 

of supplies and troops carried in each convoy This is due to the fact that all 

passenger messages are classified secret, cargo messages are classified confidential 

Detailed analysis shows that there were 21,836 confidential groups and 3,965 

secret groups transmitted in connection with the 2nd of April convoy. The next 

convoy gave rise to 18,16~ confidential and 4,47~ secret The third convoy 

@'pp roved for Release by NSA on 10-11-2013 pursuantto E .0. 1352a 
REF ID:A38365 

required 19,429 confidential and 594 secret It is apparent from these figures 

that the major function of' each of these convoys was to carry equipment and 

supplies 

Well, you all remember I am sure the various signs that were posted in 

buildings -- Keep quiet, the enemy is listening and Troop movements are very 

very guarded Now I am going to read you from a book with the strange title, 

11All Honorable Men" by James Stewart Martin, who apparently was a member of 

some OSS or Economic Bureau or one of the War time economic things of the 

government. 

"On a bleak night in February 1945, I found ieyseli' standing with 

my small party of investigators in mist at the Washington airport waiting to 

take off. As I stood in the gloom obse;-ving all the security measures that 

surrounded our routine departure, t~e~ ~l!l'c~k- out of' :he field and planes, silence 

• • ~ 1 I ~ 

and sudden orders, I remembered our disco~ery_~arlier in the war of how easy 

the secrecy of ship sailing had been penetrated by the Germans. In 1940, 41 and 

42 ships leaving American sea.ports had had the same security measures to protect 

their departures yet many of their broken hulls and water-soaked cargoes had 

washed up on to the beaches of N~w Jersey, Virginia and the Carolinas where 

German submarines had spotted them with in sight of shore. In case after case, 

every man on board had been marked before the Captain opened his orders. No 

they may not have known it, the cargoes they carried were re1nsured with Munich 

The routine system of placing insurance had put precise i•texertr; information 

on their sailing date and destination in the hands of the Germans bef'ore the 

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REF ID:A38365 

ship left port In the summer of 1941, before there was any economic warfare 

section, several trustbusters discovered-that while the American public was 

looking more and more askance at German business connections, insurance companies 

doing an international business seemed to have no such doubts about their f'ore:gn 

commitments Insurers of large risks, such as ships, cargoes and industrial 

plants, customarily spread the risk among other companies willing to take 

fractional shares. The big insurance and re-insurance companies in the United 

States which handled the largest risks have such treaties on an international 

,,,_ 

basis through arrangements with the Lloyds group in England or with the Zurich 

group in Switzerland It had long been the custom the American companies to 

place their reinsurance on ships and cargoes with the Zurich group by cabling 

information to them so they could accept responsibility for a aha.re of the 

American insurers' risk. The information ca.bled would include the name of the 

ship, the sailing date, the cargo carried, the destination a.nd the value of the 

insured property. One detail which should have raised someone's eyebrow but did 

not until the government stepped in was the fact that the Zurich group in turn 

had a reinsurance treaty with a Munich reinsurance pool in Germany The result 

wa.s that during 1941'/J and early 1941, by the time a ship had cleared New York or 

service 

Baltimore harbor, headed for a European port, the German intelligence/already had 

the sailing date in band " This goes on to tell about how anyone who was 

. interested in some of our big buildings could purchase blueprints for $ 51'/J--for 

$ 55 he had the plans of' the White House showing the locations of the fire 

extinguishers and other protective apparatus. For $ 75 he had the plans for a 

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REF ID:A38365 

new large magnesium plant, one of the bl.ueprints had an arrow pointing to a 

va1ve with a legend--under no circumstances must this valve be closed while 

the plant is in operation as an explosion wouJ.d resuJ.t. So much f'or our 

protective measures from messages. It's Just almost impossible to tighten up 

everything apparently 

Well, now, let•s see what the next slide is. I am going to pass that up. 

Tha.t 1 s some more traffic analysis and I am going to devote the rest of the talk 

to cryptanalysis The most important steps. First, the study of external 

characteristics of messages Second, study any available collateral including 

that obtained from previous solution, this means cryptanalytic continuity, very 

- iii' ...,...._ 

important. Study the beginnings and eD.d.s_of messages Search for repetitions 

. between and within messages, pre~ati~ of statist1pal 5!0unts of letters, groups 

. " . • • .,. .. .r.& ... "'f .. i 

and etc. Search for indica.torsz determine the type of cryptosystem used, 

separate the traffic into groups of messages in the same or related keys, test 

'1 -

f'or probable words, sterotypes and ~ga.e~, isologs, h_?llologs. Then reduce it 

to simplest terms 

The rest of r.rry talk will be devoted to a brief discussion of modern, 

practical cryptanalytic operation and gadgetry. Now we turn fl.l'st to a picture 

of' an old gentleman, Trithemius This picture matches the picture that the 

average layman has of a cryptanalyst Veiled secrecy bas produced an air of 

mystery and before World War II, it was possible to do much processing merely 

with pencil and paper. Now cryptanalytic work is very big business, complex , 

expensive but it pays big dividends You heard Dr. Engstrom say that at the 

present tl.Dle we are spending about a half a billion dollars Ja year on this 

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REF ID: A38-365 

activity. Now the cryptanalysis in modei-n systems has been facilitated by the 

invention, development and application of special cryptanalytic aides by way ar 

machines The nature of the problem, not merely the number of permutations and 

combinations but the type is more important. The nature of the problem is one 

of testing out the multiplicity of assumptions and hypothes~s, commonly by 

statistical methods I'll show you a picture of what I think is the earliest 

cryptanalytic device, one that I ma.de at Riverbank. in 1915 or 16 Sliding strips 

between two glass plates, I can slide them easily, they are in tracks and rubber 

rollers so I could print alphabets fast, single alphabet or a whole row of 

alphabets--the polyalphabet In 1934, I became quite chagrined that we didn't 

have any kind of machine apparatus to help us and the Navy did. I found this 

out by secret channels. The Navy began in 1932, if I remember correctly, with 

one IBM Sm', a punch, tabulator, sorter and they used ft for cryptanalytic 

purposes and there came a tJ.IDe then a couple of years later when I found out 

that there was a possibility that we could get some There was no hope that 

we could convince the Signal Corps people that we should put in our appropriation 

for this thing so there came a time when I found out that in the office of the 

Quartermaster General of the Army, there was an installation -- a sorter, 

a punch, a tabulator and that a new officer had come to take charge of this 

\ • i 

particular division The division had_to do with the accounting for the CCC, 

,. 

remember tha.t gentlemen This office! did_n•t find that Henry :Bennett who was 

..... Quartermaster General to George Washington used machinery so he decided that 

he would bave this taken out so when I found this out, I maneuvered to get 

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REF ID:A38365 

the remaining term of the contract transferred to the Office of the Chief' 

Signal Officer and that was done by a memorandum--you can see blood and tears 

on it -- which I wrote putting my case forward in my own handwriting, what we 

could do if we had a little help of that sort and this is the extract of the 

with 

first contract that we actually got :bmm mM f'or our apparatus From that 

small beginning I show you now one wing of' a big building at .Arlington Hall 

during World War II which contained nothing but lBM machinery and we had two 

such wings. They were several hundr~d feet in length, hundreds of' ma.chines 

Now I would lJ.lte very much to be.able to shov you the examples of the two 

most l.Dlporta.nt machines that contributed to the cryptanalytic victory in World = - • .. • -

~ ! 1:: i •·\.''' • .,. - fl 

' ,. ~I ; ' ? ... 

Wa.r II but I cannot These pictures would sl:low_ you a Navy type of' bombe, a word 

which we took over from the British, who took it over-from the French, who took 

Pol~? 

it over from the Dutch (I think it was the Dutch). The Navy bad a different 

type of machine from the army. They went in for " high-speed commutator devices, 

if' I remember correctly, the rotational speed of the commutators is 18,jjj per 

second, 18j1Jj revolutions per second, this is a very high speed thing and they 

were going to have at first 336 of these machines, ea.ch ma.chine having four 

commutators The reason for the f'our is that the Naval Enigma. had f'our ,Jl'otors 

and the reason f'or the 336 is that the set of' rotorsthat they provided f'or Na.val 

use, there were 336 permuta.tionsof' the rotors that could be used in one date or 

in one period--twelve hour period. The Army went in for electrical relay solution 

machines which we installed in a big wing, basement wing of Arlington Hall. It 

wae a tremendoue thing built for us by tbe Western Blectric Company and we called 

-6-
REF ID:A38365 

- - - 4 

her Ma.dame X It's J.ID.possible to show you a picture of that thing because it was 

much too big to get into a picture but I don't have a picture of' the Navy bombe, . 

I wish I had I don't know whether the Navy even bad any pictures of' the bombe 

taken It ma.y not be too late I think the Navy has one or two still in 

operation 

Now we are going to come to the specialized types of machines which both 

Services use. I can show you only pictures of those specialized types that 

Army used because I happen to have them. I don't know whether the Navy had any 

pictures taken. This is something I will have to inquire about--I got these 

together for the talk. I a.m sure however that they had as many and as complicated, 

if' not more complicated, machines than the kr"ItIY had I must say one word about 

a ma.chine which the Navy designed and I don•t know whe"lter they actually built 

1. 

it or not, called Duanne, toward the end of the war The solution of the enigma 

depended upon one thing, two things really. First, no change in the wiring 

the Germans didn•t do this throughout the war 

of the rotors/and second.}.y, the possession of a crib. That is, the knowledge, 

pretty definite assurance that a message would have a. certain word or expression 

in it. Without that you couldn't even start We didn't have any trouble getting 

.. r 

these cribs because of' the method:i..calnel;!s of the German minds, I mentioned that 

before, so that there were always cribs aVa.ilable and you would be astonished 

-.... - ' . . .. 4 

at the sources of some of them For example, the solution ~of messages to and from 

0 • 

Rummel would be depel'.ldent upon catching a crib of some lonely opera.tor way of':f' . 

the coast of Norwaly who was reporting, "nothing to report " On some o:f' these 

crib sources, the British and ourselves had double and triple coverage to be 

sure tha.t every letter was taken It was that important 

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REF ID:A38365 

Now we have to have ma.chines to make coincidence counts of in comparing 

mess.ages If you have a message of 2SS letters tand you want to compare it with 

another message with say 2SS letters to see if'ithey are by chance the same cipher 

or whether they are sl.id, displ.aced a 1.ittl.e bit. You can do this by band, yes, 

one person can do this sort of testing, comparison, about one comparison a 

which would require 

second but that would take for 2S0 messages/about 4S,0S~ comparisons, they 

woul.d take about ten hours. This is much too slow so we built a ma.chine to 

make the comparisons and we call the!ll.cgm;parators. 

t Ill ~ ; f :; ? • 1!• 

We have ma.chines now at 

-4' 

. . NSA, one a ROBIN will make 50,SSS comparisons a second We are going to have 

a ma.chine if it already hasn't been ma.de and built, the DELLA, I think it bas 

been delivered, 5 mJ.llion comparisons a second. Now this is many times ilmdter 

the capacity of 

:.tkml.x:kkR ROBIN and you can see what effect ma.chines of that speed would have 

upon cryptanalytic techniques in the future. The first comparator that was 

built, I mean a real sort of a Job, was the one built by v~ft:-.f Bush at MIT 

for the Navy It was a 70 mm comparator but we bad in Army bread.board things 

that we used for several years before the Navy's comparator was put out. 

Now I'm going to show you some pictures of some of the types of machines 

and I'm going to say JUSt a few words about each of them perhaps 

First I'm going to show you ALCATRAZ--that •s the ALCATRAZ, we JUSt passed 

it ALCATRAZ is a machine which will. make monographic and diagraphic iequency 

counts, colw:ma.r, or anyway you please It was a great big thing, very bulky 

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REF ID:A38365 

and we have better ones now 

Now this picture shows you an automatic deciphering ma.chine I don't 

know what the caption I think that deals with the Japanese 

Military Attache 

Here is a ma.chine which will locate repetition between messages and we 

call this a BRUTE FORCE machine because we don't make any attempt to do a 

first sifting. You take all the messages and just push them through the machine 

and hope that you are going to find a repetition. That's a BRUTE FORCE machine. 

Here's another one, called the SLIDE RUN machine where you have a displacement of the messages. You want to find where they should be superimposed 

Here is a machine for decoding and deciphering--! don't know now just 

what it was, it was a war-time machine 

Here's one which was called the CAMEL that was a machine for locating 

certain types of indicators in Japanese military traffic. 

And this was the CAMEL CODE INDICATOR-LOCATOR_and a specialized thing also 

for the Japanese Army ciphers 

... ~ ... .,.. Here is a machine Jd:tll which consists of an assembly of' components, some 

special Job, nothing complicated about that but just getting together the 

~ 

necessary number of' parts for the particular JOb And sometimes these things 

had to be done in a hurry 

This is a machine which was used for a system called JAS and I think that 

was Military Attache system? I forget, but anyway that was one of' the machine.s 

-9-
REF ID:A38365 

that was used Oh, that's an Army Ground Force 

This next one is Selective J-Square You remember that square that I showed 

you, it looked like a magic square, they had a number of those in simultaneous 

use and this ma.chine was designed to pick out which one was used for a 

particular group of messages. 

Next is a J-Square permutator The same sort of thing You had a plugboard here and you could plug in to see how many plugs there were. I think 

the back of the ma.chine shows a little complicated wiring that had to be 

undertaken 

This is called the PURPLE DUD-BUSTER. In connection with the PURPLE 

ma.chine, we had many times messages that had garbles in them and it was 

important to try to get out every message and to degarble by band, which was 

kind of difficult and a slow process, so ma.chines were devised to locate and 

to eliminate the busts as they were called or duds. 

This is the GEE That's a Gerni:an one-time pad system about which I told 

you This was the ma.chine that was used to generate that additive. I am sure 

it didn't look anything like the original German ma.chine 

The next is the GEHEIMSCHREIBER CRIB TESTER If you had some crib that 

you wanted to try out on one of the fish systems, this was the ma.chine that 

could help you 

This is what we called an AUTO-SCRITCBER That is what the boys called 

it, I called it RODAN, because in a way it was a thinking ma.chine It didn't 

do things quite by the exhaustion method--it would take a hypothesis, go through 

a certain number of steps testing and if it got to a contradiction, it would 

-1() -
REF ID:A38365 

say, "no, it 1 s no good, go back again, young man", and this it would do time 

after time until it got a hypothesis without contradiction and that then led 

to the solution of the particular ENIGMA key 

Here is a ma.chine called 0 1MALLEY It was a specialized arithmetical 

computer It gives the summations of products of pairs of numbers 

Here is DEMON II which is a high-speed type of comparator thing and next 

we have GOLDBERG which is the first general purpose large-scale coincidence 

ma.chine This is the first machine that NSA had built with the magnetic drum 

for storage. I think there is another picture of GOLDBERG--you can see the drum 

over on the left peeking through the aperature there 

And, of course, we had ATLAS This is ATLAS I, we had two ATLAS II's 

and these, of course, were replaced by the more modern digital computer machines, 

specialized 7~l's and other types of machines And we are going up to, you 

heard what Dr Engstrom said, higher and higher speeds all the time 

Now I had hoped to show you some s1ides or a beauti:f'ul chart which 

depicts the story of the batlte of the Atlantic--a most stupendous, fascinating 

tale, stranger than f'ictioD;_ • Tqe ~tory of the Battle:::: of the Atlantic has 

;; ~ f 

remained a profound secret. The Germans are very smart people but they 1ack 

The Germans knew that the enigmas cou1d be so1ved .. They had 

worked out on pa.per methods for solution, mathematical demonstrations and so 

on, but they said it was impractical--cou1dn1 t be done, it would take forever 

to reach a solution It never dawned on them that one cou1d build machinery 

to do what they thought had to be done by hand. That was a fatal failure, thell' 

-ll-
REF ID:A38365 

imagination Now in the Battle of the Atlantic, the Germans came to a time 

there is 

when they felt ::tUraS something strange about how their submarines meet up with 

Allied ships, way out of the way How is it! Well, their ciphers were secure, 

this they knew, so it couldn't be ciphers It must be treachery, it must be 

spies What did they do! They adopted the practice of not giving the Captain 

of a submarine his sailing orders sealed in an envelope as is often the case 

but they told him to go to sea and they would send him word This was a very 

fortunate thing for us because then we had the envelope open and the failure 

messages caused their downfall Now the funny part of it is too that they 

tried to account for the submarine losses in another way besides treachery 

very 

It must be direction finding. ~ The Allies must have some/high-pll.BX 

powered new kinds of direction finding gear and do you know, strange to 

relate, the books that are coming out 6f Germany even today, describe their 

,,. - 'IL~ ... a ..I .. I 

loss of the Battle of the Atlantic to high-powered radar direction finding - .. .... - . ... -.... I ---

~.. ... "'" .A ' ~ 

and that sort ofthing. It hasn't dawned on them that if that were the case, 

if there were such a thing as high-powered D/F, high-powered radar apparatus 

in 1943 when they began losing submarines by the scores, surely ihe art would 

now have something to say in the periodicals but, no, their JJDagination has 

I stuntified it 

~vldr;xtteM their thinking and/is still ascribed to direction finding and radar 

Let's hope that they continue in this lixttxsx~ delusion So what I have been 

telling you is a profound secret I mention to you that in a talk which 

Adllllra.l Wenger gave before the Navy War College he deliberately nu.sled them, 

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REF ID:A38365 

. . .. . "" 

the secret is so precious. I want to take this opportunity also to say that 

this country owes an enormous debt of gratitude to the brillance with which 

AdJDJ.ral Wenger and his superior, the Director of Naval Communications, Joseph 

Redman, operated this precious communication intelligence source during World 

War II and the Battle of the Atlantic in a manner that left no leakage It 

was a brilliant execution of security arrangements The subma.rinet commanders 

who were told to go where, the destroyer commanders who were told to go where, 

had no idea and weren't told so the precious secret has been kept The slides 

I tried but they are too dense, they don't show and it's a beautiful story to 

tell but I will have to pass it up. 

Now, in the Pacific Theater-- I have already indicated to you some of the 

principal reasons for successi on the failure on the part of the Germans but 

I must not fail to mention that we owe a tremendous debt to our British Allies 

who showed the way in the enigma and in many of the other systems used by the 

Germans and the Italians What we gave them were Japanese systems in exchange 

but their contribution to assist America is incalculable Besides the things 

I have mentioned on the part of t~ Germans, lack of :una.gination, in the Pacific, 

there was lack of technical know-how The Japanese mind piled complexity on . 

complexity thinking that this is what will :tx give them security They ma.de . - - ... _..... ...... -- ,. . 

many errors in their complex systems--they couldn't help it I wish I could 

... 

show you their machine for producing their random additive groups Gentlemen, 

it's pitiful, pitiful what this intelligent people did in this line. Their 

ma.chine for ma.king random additive pages number because their systems were 

-13-
REF ID:A38365 

so slow and so complicated and so open to attack, we read pretty nearly everything 

Besides the failures on the part of the Germans, the Japanese, and the 

Italians, and by the way, Dr Hall has reminded me that the Italians did use 

the Hagelin machine in their part of the war and I think it was the British who 

read most of the traffic, besides their failures in imagination, don't forget 

the 

that there was brilliance on the part of/America.nl and British cryptanalytic 

staffs, I will exep except present company, and one other thing, very 

important--lots of money, millions of dollars.1 Without the money, I don't 

think we could have done what we did The last few charts I think might be 

interesting Let's see for a moment--to give you an idea of how 

and finally winds up by courier to tl:ie-Pentagon. We didn't have really Just .. --.... ~ 

the couriers' we had telegraph "teletype lines, secure lines with crypto gadgetry 

on them. 

This is a chart which shows the production of decrypts for the period 

l December 1941 through ~ 31 August 1945 

over 11~0 messages and this is the cream of the crop--there were only translations ma.de Of the ones that showed some useful information. This is the 

Navy distribution system, the way they linked up their various COlllJ.nt operating 

centers, complicated, controlled from the center in Washington And this is 

a picture of the combined Naval-COMINT organization There were various 

centers in the British centers. 

-14-
.. 

REF ID:A38365 

'I - .. ... - - ~ 

Now I think we can s~top the lantern slide a.Ild I am going to talk for 

the next few minutes some more about-what it meant and I will read some ... i. I ~ .; ._ lt _..~ ~ .. ) '41-

• • "I' ,, 

extracts from a report of a committee, appointed by the President in l952, to 

' 

look into the cryptanalytic activities of the United States. There was a 

bit of unhappiness about the way in which-the Army and the Navy crypta.na.J.ytic 

organizations had coalesced Some people thought it was a ~ shot gun 

marriage, perhaps it was There was a desperate desire to make it work and 

in order to make it work better than it had been, the President appointed 

this committee, headed by a New York lawyer who had had some experience in 

this business during the war and they studied the case and they brought in 

a report with recommendations for strengthening the Armed Forces Security 

Agency, as it was called on its first union, and I will read from that 

report because it had some -- this tells the essence of what was done during 

the war. 

11 In World War II, COI>UNT may well have been our best paying 

investment Its cost cannot be accurately computed but an informed guess 

would be perhaps one-hal.f billion dollars annually General Bandy is 

reported to have said that it shortened the war in Europe by at least a 

year. In the Pacific COMINT located the Japanese Fleet enroute to the Coral 

Sea and again enroute to Midway in l942 enabling us to mass the carriers for 

the battles which generally are regarded as the turning point of the war 

against Japan." . - .. 1' .. 

-l5-
REF ID:A38365 

An extract from the report of the Joint Combat Intelligence Center, fa.cific 

Ocean areas on this engagement reads as follows. (and this is in the Brownell 

Report) 

"The factors that vitally affected the l3a.ttle of Midway arm were 

many and compJ.ex but it is undoubtedly true that without radio intelligence, 

that is COMINT, it would have been impossible to have achieved the concentration 

of forces and tactical surprise that ma.de the victory possible In 194-2 COMINT 

told of the critical Japanese decision not to Join the Axis war on Russia 11 The 

funny part of this is, the U S authorities thought this message was a phony 

meant to deceive us "In 1944 it helped us to pick the soft ~ spots 

. for our island advance ~ often ~~o~in~ us where the Japanese expected us to 

-...:..!"=-;-'- .t- .:A 

attack and where their troops were massed. The strategic bombing survey llll.S&ion 

which checked on shipping losses after the surrender discovered that COMINT's . ... .. 

knowledge of the size and location of the J'panese Mercha,nt Fleet on V-J Day 

of Merchant Marine 

bad been more exact than the records of the Japanese ~ Ministry/itself 

COMINT provided us with our only reliable measure of how fast the Japanese 

were losing their will to resist Our leaders bad an immediate and thorough 

record of the peace feelers which the Japanese asked 7 Ambassador Sa.'tu in 

Mexico, in Moscow, to send us through the Russians and of the explantations 

to him of how decisions were being reached and on what points further concessions 

would be ma.de. 11 In connection with this, the Brownell Report doesn't tell us, 

but you see we were reading these peace overtures of the Japanese, trying to 

-16-
REF ID:A38365 

to get Moscow to intervene,••KIDIK• to call a halt and Satu was in touch with 

the Russian Foreign Office and we set back and waited to see if the Russians 

would tell us about these peace feelers Not one word.r The principal credit 11 r ~ •..,. '* 

for winning the Battle of Britain"'has gone to radar in the public eye, and the 

so few to whom so many owei so much, but much credit is also due to another /-":. 

t~e{ wi:>f 

British few who rapidly deciphered the high level combat traffic of Lutzhaf'en 

and guided the airborne few to the defense of the right place at the right time. 

In COMINT did even better It read Rommel's intentions in Africa 

so well that the desert fox guessed the truth He coni'ided his suspicions to 

Berlin only to be told by the German High Command that such things were not 

possible 

Before D-Day in France, COMINT :f'urnished periodic appraisals 

of the situation for the High Command showing where he felt the ma.in attack 

of 

would come as well as some/Berlin's replies ignoring good advice 

presumably in favor of Hitler's intuition 

COMINT also contributed Ambassador Oshima.'s detailed reports to Tokyo on 

his pre-invasion tour of the channel defenses which led to basic revision of 

our landing plans. After the assauJ.t was launched, COMINT supplied a large 

quantity of battle reports, battle orders on every level from the OKW itself 

down to the various divisions 

Throughout the campaign in France and Germany, our estJ.ma.tes of ene.IIW 

troop strengths location and intentions were based more on COMINT than on any 

other source - ... _, -

= 

T 

-l7-
REF ID:A38365 

COMINT WAS also the principal source of information used to select strategic 

and tactical bombing targets Mft7PDHK behind German lines and it helped us to 

identify the testing of advanced weapons, such as :unproved torpedoes and guided 

missiles, in time to get our scientists started on suitable countermeasures thus 

greatly reducing the ultimate tactical effectiveness of the enemy's new developments. 

Now I must say a word or two about the protection of COMINT First of 

all you have this very difficult psychological problem that our State Department 

officials are confronted with. This is best told in the late Secretary Bull's 

and 

memoirs, met I will read you a little extract Be is talking about a meeting 

'l .. with Matsuoka with the Japanese Ambassador "Actually I already knew the 

contents of the message It contained a statement from Matsuoka to me that 

the German and Italian leaders were confident of' victory that American participation in the European war would merely prolong it and bring about the destruction 

of' civilization and that Japan could not inJure the position of her Allies 

We knew this because of the fact that our Navy and Army cipher experts, with 

remarkable ingenuity bad broken the Japanese code and were deciphering government 

messages from Tokyo to Washington and other capitals, translating them and 

sending them to the State Department for our information These intercepts 

bearing our codename MAGIC played little part in our early negotiations but 

were of great importance during thef'inal phases They enabled us to know 

many of the instructions the Japanese Foreign Minister was sending to Nomura 

and to other Japanese representatives It gave us a check on what Nomura 

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REF ID:A38365 

was reporting to Tokyo concerning the conversations he was holding with me 

and they showed that the Japanese Government was going ahead with the plans 

even while talking peace with us I looked upon them as I would look upon a 

witness who was testifying against his own side of the case. I naturally had 

to be careful, never to give Nomura the slightest impression of this special 

. knowledge I had to take care to keep our conversation limited to the knowledge 

I might have gained from him or from normal diploma.-Cic-sources This is a -

!- .. '- w ~ _I 

trick Try it yourself someday and see whether you can rem.ember where you got 

a certain piece of information from. So as to safeguard the security of these 

messages, I named one of my secretaries to handle them, keep track of them and 

make sure that they were returned to the Navy or destroyed " He mentions the 

Navy, I will add that we bad an agreement between the Services as to who would 

distribute to where Up until we had such an agreement, it was a little like, 

well little boys running to the teacher with news, the Army trying to get to 

the President before the Navy, and so on. Well, this was no-go so an arrangement was worked out whereby Army would decrypt and translate messages bearing 

the even date, that is cryptographic date, and the Navy would handle messages 

bearing the odd date and this way we divided the traffic up more or less 

equally The Army would distribute to the Chief' of' Staff and bla bla bla 

and the Navy woillld distribute to the President and bla bla bla so that there 

there 

would be no competition l.ll running to these places and gettlllg/ahead of the 

other Services 

Now, a few words with regard to the organization required for effecitve 

COMINT operations Intercept of' foreign communications and subsequent processing 

_,,_ 
REF ID:A38365 

requires the services of large numbers of communications and specia.J..J..y trained 

personnel In order that the product may be lDU!i: useful operatio:na.l.ly and not 

merely historically interesting, the intercept traffic must be forwarded most 

expediously to the processing center and after processing the final results 

promptly 

must be transmitted/to the eyahqrtrsg evaluators and other intelligence personnel 

and in some cases directly to field commands by fastest means. The scheme, 

the system, by means of' which this was done was beautiful in the Navy, in the 

Army and in the British Services Great protection, special crypto-systems, 

special security officers, so that there was no slip-up Thus a large processing 

is 

center/necessary now because of the complexity of modern crypto-systems, most 

of' them cannot be solved in the field You can solve low-grade, perhaps traffic 

analysis problems. Some COMINT processing can be accomplished in the field as 

I said before in order to meet certain immediate needs of field commanders but 

as these systems get more and more compJx:ated, Iam beginning to be very doubtful 

about that. Each Service provides for its own special needs in this category 

but COMINT processing is essentially a complex activity and much of' it can be 

r , done well only at IDaJOr processing centers where the limited numbers of highly 

skilled personnel can be concentrated ~ very speciali~d analytic machinery 

' I ... . can be installed and maintained It is not enough to install them--you know 

they have to be nursed There is no pool in civil occupations for cryptanalytic 

personnel--this is an J.m.portant fact to remember. We've got to train our own 

in pretty nearly all irasesx phases 

I want to say a few words about the great importance of' coordinating COMINT 

-2f/J-
REF ID:A3-8365 

activities with other intelligence operations and with the tactical situation 

Although COMINT is the most rel.iable, the most timely and the most egl!QJlmmxanrt 

inexpensive in the long run, the most inexpensive kind of intelligence, it must 

still be evaluated, collated, correlated and coordinated with intelligence 

coming from other sources If for only one reason a.lone, to provide data for 

cover and protection of COMINT sources When a decision has been made to take 

action based on COMINT, careful efforts must be made to insure that the action 

cannot be attributed to COMINT alone Very, very important When possible 

action is always preceded by suitable reconna.isance and other deceptive 

measures, otherwise the goose that lays the golden eggs will be killed I 

am going to give one or two examples of this COMINT cover. 

On a certain day in November 1944, an enciphered code message was sent 

by a certain Japanese staff section to a certain Japanese Air Force unit 

requesting air escort for two convoys carrying troops to reenforce the 

Philippines The message gave the number of ships, tankers, escort vessels, 

.. date of departure, port and route, noon positions for the next seven days 

The message was solved in Washington Two days after the convoy left, one 

.. .. report in a message which was also intercepted and solved, stated that it 

had been sighted by a l!-29 with strong indication tba.t the other convoy had 

~ 

also been sighted A few hX hours later, messages from these convoys 

reported losses as follows· six ships definitely sunk, one disabled, one 

on fire Later we learned from another source in addition one aircraft 

carrier was also sunk Did you happen to notice that message about the B-29? 

-2J--
REF ID:A38365 

Just didn't happen to be cruising around there but sent there to be observed 

Of course knowledge and experience point to the necessity of exploiting 

every possible advantage a tactical situation affords and the temptation is 

of course very great in the heat of battle to use COMINT whenever and wherever 

it is available. This may lead to carelessness which quickly Jeopardizes COMINT 

sources Of course the full value of COMINT cannot be realized unless operational use is ma.de of it, however, when action based on it contemplated, 

possible compromise of source must always be borne in mind and the danger of 

. compromise weighed against the military advantages to be gained A minor 

military advantage is never alone sUfficient ground~ for risking the loss of 

the source--this is a cardinal principle 

Also we must bear in IIll.nd that cryptosystems are usually world-wide or 

area-wide in distribution and changes ma.de as a result of suspicion of 

compromise may therefore have a far-reaching consequence on the ability to 

produce COMINT elsewhere 

using 

The Commander seeking a minor advantage by llllDlg 

60MINT in one locality may thus deprive another Cnmaander of much greater 

advantage or even deny it to a Commander of a ma.Jor operation 

Finally, another aspect of coordination is that between the operations 

people and the COMINT people. The COMINT people should be carefully oriented 

to give the optimum coverage for operations in progress There are JUSt so 

many facilities and personnel available and only a part of the enormous amount 

of traffic can be obtained and processed Therefore it is essential that 

the COMINT field be constantly informed of current and planned operations so 

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; 

::. . ,. -

as to direct attention where most needed This vtas a very very important 

point to get across, it was a difficult one to get across because the coilllDa.Ilders, 

people in charge of very important large scale operations were very leery of 

telling any outsiders ll!li. what they were planning to do and how and when and 

where But as we went on, mutual confidence was established and the COMINT 

people got to know what the operations people were planning and they both 

supported each other 

Now, with these remarks I bring to a close my series of talks on the 

history of communications intelligence, and cryptology I have been invited 

to stay on for a couple of weeks to participate in SCAMP activites in whatever 

way I see fit I plan to sit in on certain presentations by other participants 

in this symposium and I hope I will be able to understand a little bit of it 

But I shall be available to any of you whom may wish to talk to me individually 

on cryptologic matters or on activities of the National Security Agency This 

I will be very glad to do Also, if any of you wish to exa.mine or discuss 

any of the books and exhibits I have with me, I shall be very glad to have you 

come and visit with me Thank you very much for your patience in listening to 

my rather lengthy talks and f'or your courtesy in paying such careful attention 

to what I have had to say. Thank you, gentlemen. 

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