SUB.IECJ...,NAME 

'!'cnie SB0HB'P 

NO. 

-14 284028 

FROM DATE 

l/DGAS-14 11 Feb 47 SUSPENSE DATE TVPE FILE DElilGINATION 

SUB.IECT 

Series of Lectures i. r: l\ , ffl/l ,,,.~ s ~"' 

TO 

WD AGO FORM 734 I JAN 111411 

c mln.unicati ~ Annex 

DATE DATE 

MAIL CONTROL R•CORD 
REF ID:A71133 

·u~: 

SIGNAL INTELL1=GENCE 

and 

COMMUNICATION SECURITY 

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A SPECIAL COURSE OF LECTURES 

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Prepared under the Direction 

ot the 

Chier, Army Security Agency 

15 August 1946 

Army Security Agency (WDGAS-14) 

War Department 'Washington 

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Declassified and approved for release by NSA on 06-25-2014 pursuantto E.O. 1352a 
REF ID:A71133 

without having the kera to them. Now. vhy all the 1ecrecy about 

what ve did in th11 tield during the varT Ian•t the var over? 

WhJ can't the ruil story be told? 

It's true that Vhen V-J Day came in August 1945. the necessity ! 

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tor keeping secret many technological &dvancea made by the Army 

the Navy, an4 the Air Force during the var no longer existed, and aa 

a result rather extensive publicity could be given to them. But. 

in the com}llUn.1cat1ons intelligence field no such publicity is 

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possible, .tor by its very nature the hope or ruture success in 

this field ~el>'nda to a large degree upon aecr•c1 with regard to . I 

past •chievem.enta. I want to emphasize that Qur success throughout ~ 

the war hung by a very, very slender thread v~ich could have been . 

cut eas117 and would have denied ua extremely 1mportant intelligence I 

dire~tly contributing to the auccesatul outcome ot the var. 

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!'Tb~ most important and moat disastrous publicity leak of the 

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var occ~red in early June 1942, right att~r th~ Battle ot Midway, 

when an a~ticle appearing in three newspapers or very wide circula- , 

t1~n and a columnist with an international radio aJd1ence disclosed ' / 

' that our Navy knew in advance the Japanese p~ns tor the attack. We 

haven't time to tell you hov that leak occurred, but the etrect vas 

qu1ckJ The Japanese immediately changed their codes and ciphers and 

our N&VY, was really up against it for a number or weeks. In passing. 

I might add that the trouble with such leaks is that under our present 

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laws, it's practically impossible to punish violations or secre9y 

Without di8Cl081ng to the Vorld full details Which Would be even more 

disastrous than the original leak. . 

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However. if the Army, the Navy, and the Air Force in a tutti,re 

var are to make the most or the tremendous potent1&lit1ea ~resented 

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bJ the highl7-apec1a11zed field of knowledge forming the subject ot ,. 

this course. it's necessary that detailed instruction be giyen to~ 

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chosen tev vho may later be made responsible tor conducting the : ' 

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activities in this tield6 the conditions and circumstances under 

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which specialized operating units under their command may or can 

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produce uaetul reeulta, and hov these unite •hould best be organized 

and directed 1,n order to function moat ettecti,v•t'f • In this course ,. 

we v111 deal largely with Army units but the general principles Yill 

apply equally to Navy and Air Force units. 

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Then there's another re~son tor 11f1ng the clitatain a bit. Maybe 

not all ot,'7ou will have such an ass1gnmentJ maybe 1 aome ot Y!>U will I ' 

be commanding other aorta ot units, large ones perhaps, and t~eretore 

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an appreciation ot the contribution coDDllun1c&t1on intelligence can 

make in,aetu&l combat sttuat~ons will be valuable even 1r you don't 

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_special!&~ 1ri. the tield. Do~'t think tb&t the contribution communic&t 

I I ' tion lnt~ll1gence can make in actual combat •ituat1ona will be ';' , , 

val:iiabl• even if you don't apecialiae in the tield. Don't t~ink 

tll&t the Cdntribut1on communic&t1ona intelligence can make iai ~ 

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obvious to everybod7. Certain commanders ;in the late var, ea~c1&11' 

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,, 111 their early days of participation in actual combat, were ver7\ 

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skeptical. 

Id; me read you an extract trom an official report: 

"In lllB1' cases it vaa the unnecesa&rJ task of signal intelligence)/ Detachments in the Mediterranean Theater to overcome a general '.' 

feeling of skepticism in American Tactical Stat.ts concerning , ·,, , the value and accuracy of signal intelligence material. In ~~~ I 

several instances outright disbelief in the intelligence prod~c~ ; 

by Detachments was expressed by G-2 Staf'ts ot Headquart~ra aerv '/ 

by the Detachments. In time all tactical staff e served 1by ', , '\..,, 

Intelligence Branch Detachments became aware of the accuracy' oi '\ r\ 

intercept information; but many unf'ortUDate mistakes were made ~\ 

by tactical commands bJ" ignoring signal intelligence vae 

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]' \ developed. It is felt that such unnecessary lack of corμ"idea.c \'\ in signal intelligence operations can be eliminated before· i 

actual operations in an active theater are begun by educa~1~ 1, \ '.'\ 

tactical statts 'With the role Vh1ch ai~l 1ntell1gence ·c•:c' a?\t1'·. \ 

should play in modern tactical wartare. " \ \ [1. ~ 

t . '\ Perhaps the tev examples I'll have occasion to cite will be r 

auf'f'icient to imprees upon all or rou the tactical value ot the k1n4' 

or intelligence, commun1cat1on intelligence can ~eld. 

This course deals with "Signal Intelligence and Oommuntcat1on' 

Security", I don't think it necessary to go tar back into their 

history, but it ia necessary to define them. 

Perhaps I should begin by defining a term not mentioned thus 

tar, namely, radio intelligence, which ia the product obtained trom I 

the interception, study, and analysis or electro-magnetic em11s1on1 

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ot all t7pea. Beaidea emiaa1ons carr71ng me .. agea or co11111un1cat1ona, 

I that 1a, em1ea1ona vhich conve7 thoughta, ideas. reports, orders, and 

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so on, whether the7 be in written or oral torm, or even 1n the torm 

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ot p1cturea, ~here are em1aaiona vbich do not conve7 any qt theae l ' 

things but ·~· purel7 a1gn&le ot one sort or another, auo- &8 radar, ,. i 

nav1gat1on&l, guided-missile· control, aeterologic&l or me~eorogr&pbic 

signal• 8'd ao on. So, we may divide the r&41o 1ntelligend~ field r 

' into two aub•t1elda (l) the .sub-field which deala V1tb the interception and solution ot Vhat we will call "oommun1c&t1on-type" aignala, \ 

and (2) the aub•tield which deals vith the interception and atud7 ot 

•tnoQ.-co~i cat1on-tJP•" signals. Under a very recent arrangement, '. 

the Air Poree 11 respona1bl• tor the latter t1el4 and not JDUch v111 

be aa1d\~•bout it in thia course. Tbe r1eld 1a relat1vel7 nev, aa 

you m&J' well imagine, and there is much apad• vork to be done,. You I 

v111 be concerned largely Yith 1e&l'!11ng ae mμcb a1 you can, hovever, 

about the aub-t1eld ot radio-1ntell1gence vb~ch we call communication 

intelligence or 81gnal intelligence. And because the ott1c1&1 

designation up to the pre1ent 1s signal 1ntell1gence, I'll bave 

to use that until the term ia changed ott1c1&lly. Signal intelligence, then, 1a the product obtained trom the tpterception, study, 

and solution ot meaeagea. We a1ao include, tor p~act1c&l reasons, 

the atud7 or secret v:d.ting produced by means or invisible inks 

and m1crophotograph1c methods. 

We a110 vill deal w1th aommun1cat1on aecur1t7, which embraces 

all meaaurea designed to deny to unauthorised persona such intorm&- ' \ 

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tion aa might be derived by the application ot aignal intelligence . procedUl'ee on our ovn commun1cat1ona. 

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REF ID:A71133 

It is al.Qloat 1mposa1ble to estimate the amount ot time and 

money spent, ihe changes in plans vhich were neceaeitated, and the 

hundreds ot ot~er tb1nga involved in investigating the loss and 

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taking corrective action in the foregoing.case. , 

Thia v~s a very costly error, and wbJ did it happen? Poor 

security indoctrination is the only answer, and it was the answer 

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given by the ~nspector General vho conducted the investigation. 

Hearings disc~osed that the officers involved were unaware of the 

security regu~$t1ons imposed on the handling of the cryptographic I ' 

material they'he.d. But the hearings also d1acioaed that the Signal ,• r\ 

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orr1cer bad'received thl'ee specific letters deaiing with special ,/ 

secur1ty,A.nstruct1ona tor the cr7ptograph1c equipment assigned to 

him, and t~t 20 other publications bearing on s~curity were on 

file in the Division Signal Center. 

The Inspector General's recommendations mad• at the conclusion 

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of his hearings v~ll indicate hov seriously he considered the 

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various d$re11ct1o~s. He recommended that the C~mmand1ng General 

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ot the D1~1s1on be relieved o~ command; that hie Phief or Starr , '· I ' I 

be relieved of his &ssignments; that the Division Signal Officer, , ' ' 

message center officer, assistant message center' ,officer &nd 

mess•ge cerite,r ch1et be tried by courts martial ro~ gross neglect 

ot dui,-. 

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