I. INTRODUCTION 

•• • 1. Fiend hart mtt. 

I 

REF 1 Ip ~A~lJ.31 U t!C-.CVl/'e .J.. • r: rm 

2. Security warning - T. s. material. 

II. MAGIC - WHAT IS IT? 

1. Text of sermon - 11Magic was the word tor it" 

\ 

" 2. Read extract from page 20, 17 December 1945 issue TIME, under article 

entitled 0 .Pearl Harbors• 

•u. s. citizens discovered last week that perhaps their most potent 

secret weapon ot 'World War II was not radar, not the VT tuse, not the 

atom bomb-but a harmless little machine which cryptographers painstaking~ 

constructed in a hidden room at Fort Washington. 

"With this machine, built attar years ot trial and error, ot inf'erence 

and deduction, cJ.7P'tograpbers had duplicated the decod:!:ng devices used in 

Tolqo. Testimon;r before the Pearl Harbor Committee had already shown that 

the machina--known in AJ"Jq' code as 'llagic1-was in use long before Dec. 7, 

1941, had given ample warning ot the Jap1 s sneak attack-it only u.s. brass 

hats had been smart enough to realize it. Now General Marshall continued 

the sto1"7 of 1Magic 1s 1 mgic. It had1 

u 

"Enabled a relative~ small¥• Force to intercept a Jap invasion 

fleet, win a decisiw victor,v in ~be Battle of tha Coral Sea, thus saving 

.\ustralia 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 hava been 3,000 miles away-, tlms set up an ambush which prowd to be 

the turning-point victor.v of the Pacific war. 

''Directed u.s. s'UJ)marinaa unerringq to the sea lanes where Japanese 

conVOJ'B would be passing. 

••By decoding messages from Japan 1 s ,&mbassador Oshima in Berlin, otten 

reporting interviews with Hitler, given our forces invaluable information 

on Gel'JIBn war plans.n 

3. Time's source - Chief of Staff A:nv. 

4• Read extracts - Marshall to Dewey letter: 2 6'~a4'1' +-f- (••fe vtl/ ht 14 e,!f;;,,.,.,~~ 

"Now the point to the present dile~ is that we hava gone ahead 

with this business of deciphering their codes until we possess other 

codes, Oe:nnan as well as Japanese, but our min basis of information 

1"9g&rding Hitler's intentions in Europe is obtained f~ Baron Oshima's 

Declassified and approved for release by NSA on 08-08-2014 pursuantto E.O. 1352a 

. ' 
REF ID:A71131 

messages from Berlin reporting his interviews with Hitler and other 

of'f'icials to the Japanese Government. These are still in the codes 

involved in the Pearl Harbor ewnta. 

11To explain turther tbe critical nature of this setup which would 

be wiped out almost in an instant it the least suspicion were aroused 

regarding it,, the Battle ot the Coral Sea was based on deciphered 

messages and therefore our fn ships were in the right place at the right 

time. Further, we were able to concentrate DI( our limited f'orces to 

meet their advances on Midway when otherw1Be we almost certainl.7 would 

have been some 3,,000 miles out of place. 

"We bad full intormtion of' the strength of their forces in that 

advance and also of tbe smaller force directed against the Aleutians which 

tinall.T 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 avail.able to them,, 

and what is of vast importance,, we check their fleet movements and tbs 

movements of their convoys. 

~The heavy losses reported from time to time which they' sustain by 

reason of our submarine action largeq results from ths tact that 118 

know the sailing dates and the routes of their con'VOJ'B and can notify 

our submarines to lie in wait at the proper point. 

8The current l'Bids b7 Admiral Hals971 a carrier forces on dplpanaae 

shipping in Manila Ba7 and els•here were largeJ.7 based in timing on the 

known movements of Japanese convoys, two of which were caught,, as anticipated,, in his destructive attacks. 

* * * 

"The conduct o:t General Eisenhower's campaign and of all operationa 

in the Pacit1c are closely re1ated in conception and timing to the information we secretly obtain through these intercepted codes. Thq contribute great~ to the victo17 and t~mendously to the savings of American 

11 ves, both in the conduct of current operations and in looking toward the 

ear~ termination ot the war.a 

* * * 

5. "llagic 'RB the word for 1 t." 

Tk•se •S- 'i•"" "'&..k."' c f •If•• eo4 6. I.qng protf&cted hearing of the Joint Congressional COlllDittee. (Read excerpts) 

""' ~ c:i&L d-.. ..i 

11With the aarciae of the greatest ingenuity' and utmost resourcefulness,, 

regarded by the cOJllJd.ttee as meriting the highest commendation,, the War and 

Navy Departments collaborated in breaking tbs .11.panese diplomatic codes. 

Through the expl-01.tation of intercepted and decoded messages between Japan 

and her diplomatic establishments, the so-called Magic, a wealth ot intelligence concerning the pu.rposes of' the Japanese was available in Waahington.u 

• 
REF ID:A71131 

and again, on page 2)2: 

• ••• all witnesses familiar with Jla.gic material throughout the war 

have testified tl&t it contr:l.buted enormously to the defeat of the enmqy, 

great~ shortened the war, and sawd many thousands of lives.• 

7. The hightest in A.n\r, Nav and State testified to this effect - and yet in 

open hearing, nm.ch was limited. 

8. Read extract - Memo tram Secretaey of State to AC of S, G-2 - .3 Januaey 19441 

11'lhe Department bas found this •terial valuabls at all times, and vital 

in a number of highly important situations. It would appear that information 

of this kind, and its ana:q&:ls, will be even more vital in the future than 1n 

the past, both during the period of actual hostilities, and tor a considerable 

period ot time (which cannot now be estimated) after the hostilitiea may be 

concluded. This material is of great nlue in determining the facts on which 

...l • poliey JllUBt be formulated or action taken.•• 

'ilJ/l.. "*'iMll '~ foe'~ e. he w ..,...:. ~ u '°'' 

9. What is thia magic? 

(a) TDE'S application to machine - wrong. 

(b) Anq had such •chine - but teclmlcians who produced it b7 pure analysis, 

bulldog perseverance, and brilliant research never gaw namd machine "llagio.• 

1. '· (c) •'llagic• first usea\b7 Britis!J- as a cover name tor product of h1.ghJ1' 

specialized operations which we call 

(1) Signal Intelligence., or 

(2) Comnunication Intelligence. 

(d) "Vagic Summa17 .. n .,. r ~ , ·,,.r ~ \'' • -:'1 ~I l'l<~u.1 ~,,,.11_ I( - "Ci 

III. VALUB OF MAGm - Ist's examine more closeq: 

l. (a) Cmmmnique in New York Times - Ju~ 12 - 1.3 - 141 

"Jul1' 121 Aitape-Wawak1 our medium units attack planes and fighters, 

with twenty tons (of explosives), harassed enem;r-occupied coastal sectors 

from Wewalc to Yakamu.l, starting tires in bivouac and supply' areas. Air and 

naval patrols attacked lines of communications.n 

I 

"July 1.3: 45,000 Japanese troops trapped between Aitape and Wawak on 

New Guinea since April have started a desperate battle to .tight their W&7 to 

the northern part of the islancl. 11 

••Juq 14: Our outposts inflicted hea'VJ' casualties in a prelimina17 

engagement with an enemy force moving westward, apparentq to attack our 
REF ID:A71131 

our Aitape position. our medium units and attack planee with 53 tons of 

exploaivas, struck ene:m;y concentrations in the Yakamul and Wewak areas.n 

(b) Inside sto17 behind it -

(1) 28 May 1944 message, available l .June, mentioned supplie.a :needed 

by the 18th Japanese Anv (control.ling operations in eastern New Guinea) 

must arr1'98 at Wewak by end of June in order to be of use on "attack on 

.AITAPI.• 

(2) 24 June 1944 massage, the Southern Army stated 18th A:m.r would 

attac~AITAPI. 

(3) Other fragmentary messages confirmed this. 

(4) 20 June 1944 message (aw.ilable 25 June 1944) from 18th Al'!IW' 

planned all-out attack on U.S. Aitape perimeter on Jul.Jr 10, giving detailed 

diapoaitiona and operations. Total strength of forces involved about 20,000. 

(5) Attack was made and defeated with heav losses for the Japs. 

2. Sto17 how Jap dupliciy- was thwarted. 

(a) Extract New Yodc Times - 5 August 19451 

"The long suspected fact that Japanese hospital ships, bearing Rad 

Cross insignia, have been car1'7ing supplies for the Japanese m1lita17 

torcea was contiimd toda.7 when General MacArthur azmounced that such a 

vassel, carrying guns and shells as well as personnel, had been boarded 

in the Banda Sea near T1mdr Island Saturdq. 

"When bandages were removed from s oms 1 patients 1 no wounds were 

found ••• prel.1nd.na17' examination disclosed 23 heav mchine guns, 15 

light mchine guns and an un1etermined number of 75 DDL shells. The 

shells were packed in bona labelled 'medical supplies••" 

(b) Inside sto17: 

(l) Earq 194S, it became apparent (from reading Jap traffic) that 

the enem;,y- was attempting to redepl07 their forces in N. E. I. 

(2) One objective - to withdraw units from Banda Sea area to Java and 

Suma tea. 

(3) By June, lack of transl>ort forced them to utilize hospital ship 
REF ID:A71131 

TACHIBANA 11ARU (contrary to Geneva Convention) 

(4) Ship (renamed IBR<BE MARU) assigned 1500 troops ot 11th Infantry 

~ and 150 tons ordance and munitions from TUAL in the ICRI Islands to SURABAYA. 

( 5) Precautions to prevent d1scowry1 

( 8 ) Supply' of' hospital clothing tor troops. 

I 

(b) Dail)' sick reports. 

(c) Lists of' medical supplies. 

(d) Sending regimantal colors b;y air. 

(6) Ship left TUAL 1 August - scheduled to arriw SUMBUA. on Sth. 

(7) According to New York TimBa account, the TACHJ:B4Nl, although 

marked b:y f'lood lighted red croeses, twenty f'eet high, 118.B halted north 

ot TDIOR b:y two dast1'0)"8ra. 

(8) Search party f'oundt 

(a) Cases marked "Medical supplies0 containing nmd.ticms. 

(b) Only wounded - one sore thumb 

(9) This was no accident. 

3. Interesting tact - that Japa never suspected solution of their syatem. 

4. Pinal aample: 

(a) late 1943, Germans !aced with desperate shortage of critical items -

metals and precious drugs. 

(b) Raad excerpt New York Times - 10 November 1943• 

"The story ot a newr-ending tight between ingenious enem;y smDgglera 

and the dogged, persevering men handling the blockade of Europe wa~ told 

todq by the Minis tar of Economic Warfare. 

"Soma weeks ago, tiw ships p:qing between Buenos Aires and Spain 

were mlted by the British control points tor search with the following, 

al.moat melodramatic results 1 

n40 drums stated on navi.certa as containing paste were found tull 

ot liver extract, an important base in f'ood cmpound tor U-Boat craws. 

r 
REF ID:A71131 

"12 dl'18 had false bottoms, smeared with putty, and embedded in each 

drum was a disk of' platinum, 31

' in diameter, 1/4" thick:, and weighing a 

pound. The7 are worth more than 84,000 apiece. What is f'ar more important, howewr, is that they are worth a king's ransom to the Germana as a 

factor 1n the manufacture of' nitrogqcerine tor exploaivas. 

1 •Also in the cargoes were six tons certified as bacteriological peptone, when 1n fact they were stutfed with small containers of gland extract 

powder for the treatment of' shock:." 

(c) Inside sto17s 

(1) Series of' messages between Erich Otto Meyneir, German Charge d 1A.f'tai:raa 

in Buenos Aires and Berlin. 

(2) Complete arrangements of' the cargo was described. 

IV. DI IS IT DOD? 

l. Before explaining, again stress saour1.t7. 

(a) After V-J da.71 necessit7 tor keeping technological advances during the 

war no longer existed. 

(b) In SIGM no ~licit7 possible as f'uture success depends upon degree 

ot secre07 with past achievements. 

( c) Effect of "Black, Chamber11 and 11Pearl Harbor." 

(d) Success being on VBl"1' slander thread through entire war. 

MlbWftY (a) Battle of lleQu,pg - June 1942· 

(1) Articles in 3 newspapers and a radio columnist disclosed we knew 

in advance. 

(2) Jape changed codes. 

(3) Rav up against it for weeks 

(f) Dif'f'icult7 of punishing violaters of' security without disclosing to the 

world £!!!! details which would !!! !!!!:!. disastrous ~ original ~· 

2. On. other hand, need for lilting curtain a bits 

(a) lack of' appreciation b7 commanders. 

(b) Read excerpt f'rom report : 
REF ID:A71131 

"In ma~ cases it was the unnecessary task of signal intelligence 

. Detachments in tm Mediterranean Theater to overcome a general feeling 

of skepticism in American Tactical Staffs concerning the "f'Blue and 

accurac7 of signal intelligence •terial. In sewral instances outright 

disbelief by the intelligence produced b7 Detachnents was expressed 'bJ" 

G-2 Staffs ot Headquarte!'fl serwd by the Detachments. In time all tactical 

staffs served b7 Intelligence Branch Detachments became aware of the 

accura07 ot intercept information; but maJl1' unfortunate m:iatakes were made 

b7 tactical comDBnds b7 ignoring signal intelligence information before 

the proper c~nfidence in such intelligence was dewloped. It is felt that 

such unnecesaaey lack of confidence in signal intelligence operations can 

be •liminated before actual operations in an active theater are begun b7 

educating tactical staffs 1Ji th the role which signal intelligence can and 

should play in modern tactical warfare. 0 

3. 1Magic11 is done b7 Signal Intelligences 

(a) Signal Intelligence is the product obtained from interception and 

ana~is of traffic passed b7 the various means of communication and from the detection 

of' secret inks, 111fcrophotograpl4 ' and open codes. 

-. (b) In simple terms, object of signal intelUgence is to intercept enemy 

massages and answen three questions : 

(c) 

(1) Who sent the message to whom? 

(2) Where are the correspondents? , 

(3) What do the messages &&J"? 

~ 

All important. Fundamental error to think that the bald text ot a ~ , 

message is necessari~ capable of correct interpretation without identity.l.ng the 

originator and the addressee, and, on m&Jl1' occasions without having additional background to appreciate its significance. 

4. Ylha'J; are the operatiom involwd? 

(a) Interception 

(b) Traffic ArJa4'&1s 

(c) Cryptana~is 

(d) Translation and emendation 

(e) Exploitation or production 

(.t) In.tomation 

1 
- - -------------------------

REF ID:A71131 

j Ji; £.val11ot1 o ~ 

(g) llilitaey intelligence 

(h) Dissemination 

@ Secret inks 

s. Reliabilit7 

(a) Onq one source ot intell1gence - others are : 

(1) Air and ground reconnaissance 

(2) Prisoners 

(.3) Captured documents 

(4) Secret agents 

(S) Other sources 

rt.."· pi#' (b) By far, most reliable as it rewal.a innermost thoughts and in swtrwords 

what en&JV is planning and doing. 

(c) Measured by results, it is al.ao tar more t'Smeq and inexpensive. 

(d) Quotes of what Germans thought ot it from "Ge:rmn Operational Intelligence• 

"Signal intelligence was a chiet source of 1Dto:rmt1on in the German 

A.nv"• ••• Good intercept woztc, producing, as it did, al.most 90 percent 

reliable 1nto:rmtion, as invaluable. n 

and again: 

"During the invasion, the G-2•s in the Weat drw about 60 percent of 

the operational.l1' important intormatiqn tro:m signal intelligence. The 

remaining 40 percent was derl.wd from all other fields of intelligence. 

•••Yost of the inf'ormationwaa deduced from the organization ot enem;r 

radio traffic networks, from decoded messages, and from the radio nets of' 

the enemy Air Force liaison ot'ticers who were attached to ground troops. 

Based upon this iJif'ormation, the evaluation center of signal intelligence 

often came to conclusions which, at first, sounded hypothetical to the 

operational command and were therefore doubted. In 90 percent of all 

these cases the ewnts verified the signal intelligence information so 

that evantualq mare credence was giwn to its conclusions.• 

(e) Also for Americans - German counterat.tack against Mortain-Avranches 

corridor in August 1944· Jm.ch known through Signal Intelligence of' enemy strength, 

positions and intentions at least )6 hours before. As a result Bradlq able to bring 

up necessar.v re:l.ntorcemanta (U.S. VII Corps~ including 4th, 9th and )oth Divisions, 

)d Amored Division and part of 2nd Aniored Division involnd in this). 

! 
REF ID:A71131 

' 

(.f') Reliability ia great but not always 100 percent. 1f1V? (Best to 

check when able) 

(1) Man who's message 7011 aN reading may be mistaken or he may 

have erroneous information and not know it himself'. 

(2) Messages may have garbles and lead to erroneous interpretation, 

or there uq be serious errors in translati"on (slide). 

(3) Messages may be "phonies" (hard to tell). 

(4) Messages ray be practice message not easily identifiable as such. 

(a) In\1945, tr&:f'fic intercepted in Ita'.q •de reference to InII 

Corps (not previously identUied). Ewntually diacowred prefaced by 

"'t••••C\ message," and that identification was in error. 

9 
:,~~~~~,---.--~~~~~~~------------......... I REF ID:A71131 

; f 

') LBCTURE /12 

I. COUBSB - "Signal Intelligence and Communication Security." 

1. Up to now have discussed only Signal Intelligence. 

2. COJDDUnication Securlv of equal importance and goes hand in band nth Signal 

Intelligence. -Siamese Twina-all has been known aa s. I. s. 

3. Definition: 

a. Signal Intelligence is the product obtained lrom interception and ana~ia 

ot tratfic passed by the various means of c011DUnication and from detection of secret 

inks, m1crophotogra.phs 1 and open codes. 

b. Communication Securitz embraces all measures designed to de!V' to unauthorized 

persons such information of military w.lue as might be deriwd from our COllllllU.nications. 

II. BRIEF msTORt (use slide) 

ITO 

III. EXTENT !! -.s .. m..,H.,.A-.L INTELLIGENCE - World War II (use slide} 

IV. TYPICAL SIGNAL INTEWGENCE OIGANIZATION (use ETO slide) 

V. Now discuss in more detail various phases of Signal Intelligence Service. 

a. Signal Intelligence 

(lJ Intercept Operations 

(a) AcCUJD11lation or data - frequencies, call signs, schedules, and 

procedures. 

(b) Chatter of utmost importance. 

( c) Clearly allied is D/F - radio nets parallel order of battle. 

(d) Radio finger printing. 

(e) Tina 

(t) Beacons, radar harmonica, navigational aids. 

(g) Tectmiques and equipment at an authorized receiving station quite 

different from an intercept station. 

• 

(h) Strategic fixed intercept different from tactical. 

(1) Impress - interception quite different from ordinary reception and 

considerable more training required. 
RESPONSIBILITY FOR CODE AND ~E!D\!t'i'¥J.J.!~1THE U S ARMY 1861-1945 

BEFORE 1861 

1861-1865 

CIVIL WAR 

1865-1898 

1898 

lcHAosl 

SIGNAL CORPS 

MOBILE STATIONS IN THE FIELD 

SOLUTION ACTIVITIES INCIDENTAL 

SIGNAL CORPS 

CODE COMPILATION, NO SOLUTION 

SIGNAL CORPS 

MILITARY TELEGRAPH CORPS 

FIXED TELEGRAPH LINES 

SOLUTION ACTIVITIES INCIDENTAL 

SPANISH-AMERICAN WAR EXISTING CODES USED, NO COMPILATION, LITTLE OR NO SOLUTION 

1898-1917 SIGNAL CORPS 

CODE COMPILATION 

THE ADJUTANT GENERAL 

ONE CODE COMPILED (1902) 

ARMY SERVICE SCHOOLS 

SOME TRAINING IN SOLUTION, TOWARD END OF PERIOD 

1917- 1919 (IN WASHINGTON) (IN FRANCE I (IN FRANCE) 

WORLD WAR I MILi TARY INTELLIGENCE DIVISION, SIGNAL CORPS G-2 AEF 

GENERAL STAFF COMPILATION SOLUTION OF GERMAN 

COMPILATION INTERCEPTION COMM UN !CATIONS 

SOLUTION DIRECTION- FINDING 

SECRET INK WORK 

SHORTHAND 

G-2 COMMUNICATIONS 

1919-1929 (IN NEW YORK ) (IN WASHINGTON) (IN WASHINGTON I 

MILITARY INTELLIGENCE DIVISION SIGNAL CORPS THE ADJUTANT GENERAL 

(WITH STATE DEPT SUPPORT) CODE COMPILATION PRINTING 

SOLUTION DISTRIBUTION 

ACCOUNTING 

CALL IN WASHINGTON HEREAFTER) .--~~~~~~~~~~~----. 

1930- 1934 

1934-1941 

1941- 1944 

WORLD WAR JI 

DEC 1944 -

SEPT 1945 

SEPT 1945-

SIGNAL CORPS THE ADJUTANT GENERAL G-2 

SIGNAL INTELLIGENCE SERVICE 

CODE COMPILATION 

TRAINING IN SOLUTION 

GENERAL TRAINING 

RESEARCH AND DEVELOPMENT 

SIGNAL CORPS 

.SIGNAL INTELLIGENCE SERVICE 

CODE COMPILATION 

TRAINING IN SOLUTION 

GENERAL TRAINING 

INTERCEPTION 

CURRENT SOLUTION 

RESEARCH AND DEVELOPMENT 

PRINTING 

DISTRIBUTION 

ACCOUNTING 

SIGNAL CORPS 

PRINTING 

DISTRIBUTION 

ACCOUNTING 

ALL PHASES OF ACTIVITY THROUGH 

SIGNAL SECURITY AGENCY AND 

SECOND SIGNAL SERVICE BATTALION AT 

ARLINGTON HALL STATION ANO 

INTERCEPT STATIONS 

STAFF SUPERVISION 

G-2 

STAFF SUPERVISION 

G-2 

STAFF SUPERVISION 

SIGNAL CORPS 

ADMINISTRATIVE CONTROL OF ALL PHASES I OPERATIONAL c!.;:,L OF ALL PHASES I 

G-2 

COMPLETE CONTROL OF ALL PHASES THROUGH 

ARMY SECURITY AGENCY AND 

SECOND SIGNAL SERVICE BATIALION AT 

ARLINGTON HALL STATION• 

INTERCEPT STATIONS AND THEATERS 

S!CPCEI 
REF ID:A71131 

(j) Stumbling block to interception 

1. Radio silence - - a. Quote Ge!Wln document dated 20 March 1943: - 1'While preparing for an attaclc, the Russians keep strict 

radio discipline and often impose radio silence, thus 

making most difficult the useful employment of radio 

intercept in that sector." 

2.• Battle of Bulge 

I 

On S llovember 1944, radio silence ordered tor units behind 

lines in East Holland. On 9 November, German C inc, West 

ordered immediate cessation of radio traffic in FortreSI 

Area West and subordinate units. On 10 December, message 

read all SS units observing radio silence. 

Most striking etf'ect - radio silence •a lllf'twafte New 

Years 1945 - last bid for air supre•cy - IFF navigational 

aids - all silenced until operation. 

2. Use of landlines. - (k) Counteraction 

!• Radio operators require extensi1'e training. 

2. Mobility ot units require use of radio. -

3. ImpossibilitJ' of landlines - Pacific Operations. - (2) Traffic Ana~ia 

(a) lf.ay &l'JSW'er the Dwho" and "where." 

(b) Study of eneJqy traffic to overcome procedures,, dail-7 changing,, unaytamatic call signs, changing frequencies, net organizations, 

preservation of contimity. Extracts all information w/o reading 

the message. 

(c) Fusion with other sources of inf'oimtion. 

( d) F.apecialq useful in tactical uni ts. 

(a) Provides "cribs • 11 

(f) May be only' source n•ter schus-8111 - example-

(g) Big~ deaireabl.e be checked against other sources - inferences are 

inevitable. 

2 
REF ID:A71131 

(3) CryptanalJ'Bis 

(a) May' answer 11who11 or 1'where. n 

(b) Does give 1'what11 1a aaid. 

(c) No magic - no crystal ball. 

(d) A science using straightforward scientific principles and procedures. 

(e) Techniques - mathenatical and statistical - element of luck and 

impU.ea 1t1maw how .11 ..... h .. ,. 

(t) Describe codes and ciphers. 

(g) Cipber machines. 

(h) High, medium and low grade syatems and their general exploitation in 

Signal Intelligence. 

(i) Example of 3 ~ code used by German Iurtwaffe - trigger happy 

Germans 

(j) ns D 109' s trom RJ 2 tqing out over Mii at 1430 t:cy:l.ng in over RM 

1515 low level attack." 

"2 MB 109' a up at 0830 down 0930 LO." 

(k) Teclmiques s 

1. Study of the external characteristics of messages; 

2. Study of any available collateral infomation, including that - obtained from previous solutions of syatems used by the same 

ene:m;,y organization (this is what is meant by 11 c:eyptana].ytic 

continuity" without which the cryptana4'11t is great~ handicapped). 

3. Study' of the beginnings and endings of messages; -

!t- Search for repetitions within and between messages; 

2.• Preparation of statistical counts of letters, groups ot letters, 

cmplete code groups, and the like; 

6. Search for indicators; 

?. Determination of the type of cr,yptograp}\y used. -

8. Separation of the traffic into groups ot messages cryptographed 

1n the same key; 

9. Test~ of probable words assumed to be present in the message; -
(4) 

REF ID:A71131 

10. Search for messages which may be presumed to contain the 

- . same plain text enciphered in dif.f erent ways. 

(1) Emphasis on cryptograph continuity. 

(m) Use of machire 1'/• 

(n) Stress intel'Blationship of thr9e phases. ~~~ 

Translation a.nd Emendation 

(a) Kighly trained - skill, imagination and flexibility of J11J.nd. 

(b) Voice interceptor. 

(c) Intimate knowledge not only of language - but colloquialisms - basic 

military terms -

(5) Produ?tion o,. E-"fle/ro..."'t1..,. 

(aj Eliminate delays, establish short cuts, standardize procedures, use 

machl.nery. 

(b) Save on cryptanal.ysts. 

(c) Establishment of priorities - hundreds of thousands of messages. 

(d) Scanning units. 

(6) Information 

(7) 

(a) Selection of material • . {b) Public~"'in proper form. (During height of activity, Signal Security 

Agency in Washington alone produced an average of 1000 bulletins a day, each I'rom l to 5 pages long J 

These conclude functions of Signal Intelligence Service (Intell ~ide) 

and rest taken up by G-2. - ~"\ '1. ~ -~ 

~~ 

~ ~ 

(a) Communications vital factor. 

(b} August 1945, TTY in U.S. above $59,000. 

VI. PROTECTION OF SOURCE OF SIGNAL INTELLIGENCE 

1. Convoy on high seas - direct action as result - enemy concludes you solved their 

codes. 

2. Tunisia example -

4 
.. 

REF ID:A71131 

'In Tunisia, f'or example, a costlY" error was made when intelligence 

from radio intercept was not handled properq-. Two German coded messages 

were intercepted, sevaral hours apart, and broken. The first massage stated 

intentions of a German attack at a particular hour. The second message 

postponed the attack and gave the new tillEI of the jump-oft. Both messages 

were. forwarded to the Allied tactical comnands as soon as they' were broken. 

One command, attar receiving the second message, mde a radio broadcast, 1n 

clear, referring to the German intention to attack, stating that it had been 

postponed, and giving the exact tims as reported in the Germn massages. 

As a result of German intercept services reading the broadcast the attack 

was again postponed. Furthermore, later German messages intercepted stated 

a realization that the Allies were reading German tactical codes. In a short 

time all codes being read regularly by Allied signal intelligence units disappeared from the air, and a dependable source of intelligence was lost to 

the Allies until the new codes were broken.• 

&f" M,,_ - ~ ,,.-::X -uJ 2. ~ ~ ~ t-......,. 3. Artillery mample. r:....w:t~ 

~\{~~ 

,,,,,, 

:.~~~~~ 

l\AA"-tr•• :a..t;r ~ 

~~::~·1--.,.. 4• Jap eample J.~ - ie-4···' .t.oi • .,...... ... .,u·-.&.t .._ -"""'..c ., ~(ii • .,. J. ..,.. ecOn a certain day in November 1944, ,an enciphered code message was sent 

by a certain Japanese staff' section to certain Japanese Air Force units, 

requesting air escort for two convoya carrying troops to reinforce the 

Phillipines. The massage went on to say that the convoys consisted of ten 

ships, tankers, and escort vessels; on what date it Tras to leave and from 

what port; what the route was to be, even to including noon positions for 

the next seven days. This message was solved in \'lashington. Two daJS after 

these convoys sailed, one of them reported in a massage, which was also 

intercepted and solved, that it had been sighted b:y a B-29, with strong 

indications that the other convoy had also been sighted. A tew hours later 

massages from these convoys reported the following losses: six ships 

detinitel,y sunk,, one disabled and one afire. Later,, we learned from another 

source that in addition one aircraft carrier was sunk. But did :you notice 

the message about the B-29" It didn't just happen& 

5. Definite rules laid dawn on use ot this. 

6. ~ authorized recipients. 

7. Special channels 

B. Never take owrt act to comprmise source • 

5 
... 

I 

- REF ID:A71131 

f 

IECTURE #3 

I. COMMUNICATIOM SECURITY 

a. (1) - .=:-President of u. s. and CoJ11111ander in Chief, u. s. Navy, 

Chief of Staff, Army and other high ranking Government officials joumeyed several 

times half' wa7 around the world to attend special meetings and contdrences. 

{Travelled safe]J') 

(2) On the other hand, the gentleman who was reported to have said in 

1941: "I'm looking forward to dictating peace terms in the 'White House.~ JB!I;, 

the Commander in Chief of Jap Comb Staff' .. Admiral Isoroku Yamamota, while in 

the course of an ordinary inspection tour, died in a flaming Jap bomber that 

crashed on the Solomon Islands in April 1943· Accident? "Accidents don't 

happen - they are brought about. 11 

b. (l) Ever think about the tre111andous number of communications required 

to handle an operat:r:on like Torch and Overlord? 

(2) Communication securit7 responsible for success. 

c. Communication securi. ty - embraces all measures designed to deny to unauthorized persons such information of military value as might be derived from 

our communications. 

d. Three basic elements to cmmnunication securit7.: 

(l) Pb;ysical securi t7 

(2) Transmission security 

(3) Cryptographic securit7 

~h P:t:\Ysical security safeguards s 

(l) EJc;tensive and comprehensive accounting system for every single item 

(2) Office courier for delivery 

(3) Complete and adequate instru.ctions and means for destruction in 

emergencies. 
REF ID:A71131 

(4) Rules for p}Vsical safeguarding (code rooms and etc) 

( 5) Cryptographic clearances 

( 6) Inspections 

(?) Colmr Incident 

t. Transmission security 

(1) Provide operating procedures which give least inforration to enem;y 

(2) 

(3) 

(a) Hidden addresses 

(b) Changing call signs and f'requencies 

Monitoring - checks on violations 

• 

Prevention of deception by enenv 

g. Cryptogra~hic seclirity 

()'9A. 

(1) Provision of adequate cryptographic systems to meet all needs - l!FVeihigh level material - unbreakable-. (Maintenance) 

( 2) Continuous research in this field - for cryptographic lmeasages lcif ony • cif'ax. 

(3) Cryptographic systems used by ArntY divided into: 

(a) Normal 

(b) Standby 

( c) Emergency 

(4) cryp'ffonets - world wide - isolation system, etc. 

( 5) Reporting of compromises (AR 380-5) 

(lrfarine on Kwajalein, who during mop up operations in June 1944 \ 

stUDl>led across body of a dead Jap - a piece of water soaked paper lying beside 

Jap attracted his eye - 'WBS in English. Paper was Mavy Department document - a 

code wideq used in Pacific. Jap writing on it - indicated "received 3 January 

1944.n Immediate check made as to responsibility for loss of document - narrowed 

2 
REF ID:A71131 

.. _ 

\ 

'down to~ specific squadron of Army bomber co'llllland. Investigation revealed a 

Liberator was shot ~ ' down. Squad' com1nander said he saw plane shot down and crew ~ -

capturea and report,e9 the loss to higher authority and assumed higher authority 

would take care of loss of code. Result no one reported its loss. Jap was 

found 8 ·January. Must assume codes read for 5 days.) 

~ II. THE ARMY SECURITY AGENCY 

(history slide) • , 0 I 

~~i:; 1tC-P - IUl .. 

~ I_ - L 0-tG~ -1~~~:~ 

a. 6 September directive -

- ' 

b. World-wide organization " 

- .. c. Provides a service to a-2· J - rr" 

d. Organization.and function (2 slides) 

t.~ Doctrine letter) 

III. 

I ' 

' Be.cause o 

• 1 

great technological adva for col'lplete 

I 
REF ID:A71131 

COMCLUSION.: , 

In last three lectures - tried to remove some of the aura ,.., romance 

which popular writers are in the habit of attaching to this subject. 

It is hoped that you have seen, because of' the great technological advances in this field, the need for complete integration from top to bottom -

speed of' cmnmunications - the establishment of' ASA as a step in the right 

direction. 

Further hope you have seen how radio can be a two edged sword. Without 

..:. 

it itJ.s dif':f'icult to function. Improperly used, it may bring disaster. 

Above all, it is hoped you have gained some appreciation of' the importance 

of Signal Intelligence to our National Security.~~ ~ ~ ~ .... ~ ~ ~, 

We must accept as our axiom that the weaker our military and naval establishments, the stronger must be our intelligence safeguard. 

In closing, again emphasize the JJD.portance of avoiding unnecessary discussion of what has been disclosed to you ' in these lectures.