\ 

,. 

REF ID:A655~· 

f'or use with 

l'l.r 'il-3b • SI31l.AL CCP.l-S 1:'~ELLIG.G J:E 

(2 Sep.tcmber 1942) 

pendin~ ?Ublicatio~ of' a mnnunl on the 

H:ss w:r A?:D FU;CTIO! s O? '.l'! :c .1.ffi.ff" sr::::u:ill'Y .AG31·cy 

I 

"The 1nf'ormo.t1cn contained herein is not to 1-e oons'idered 

11.s an i:>f'1'1oiai' po.::-t or Fli 11-35. hut merely o.s a1 interim subI ' stitu&e until such time as 11 new men.m.l is pt..bluhed by the 

liar Department coveri"l~ sib'?lal ::.n'tellibenaQ s.r.d cdmml.Uliaetion 

seour:!ty aotl vi ties." 

Declassified and approved for release by NSA on 04-24-2014 pursuantto E.O. 1352a 

• 

~ 

• 
REF ID:A65567. 

~ESTRitiTEii 

SlJPPLllDT.ARY INFORIUTI-OI 41m CCllRBCTION SHEET 

tor 'fUl8 w1 th 

Fii ll-35, smNAL CCBPS INTELLIGENCE 

(2 September 1942) 

pending publication ot a manual on the I 

MISSION AND FUNCTIONS OI' THE .&RMI SICURIT! AGENCY 

1. In general, the organization, ~ctions, and responsibilities ot the 

Signal Intelligence Service, which are described in Fii 11·35, Signal Corps 

Intelligence, 2 September 1942, appl.J' to ~ present signal intelligence and 

communication securit7 organization tor the Arllf1 - the ArfllJ' Securit7 Agency. 

Pending publication ot a field manual on the mission and .f'unctions o: lihe 

Ar'fl11 Securit7 Agen01, the supplementary inf'ormation contained herein, mn 

those portions of 111 11-35, •hich are listed in paragraph 2, below, may be 

used as interim substitutes tor the new manual. 

2. The inf'ormation contained in the portions of FM ll~35 whi"h e.ra 

listed below is considered· to be auf'ticiQntl.y current to be used al' a git!:le 

' I 

in the instruQtion of Signal Corps Rare classes, prov1di-ng tha~ ref a~&~r~a 

to-the 11Chief' Signal Officer" are chd.nged to read 11C!:J.ie!", Amy Securitl' 

yenc1"J 11Signal Corps" to .

11Arm:r Security !genCl"; 11Sipal Intelligence I • 

Se1"V'ice" to 11Ar!y Security J.genc1 orpnization11"or "Am Securitx ~"; 

I ' "Signal Officer"· to 11Al"mt Securi tr J\gencx Liaison otti-cer" i etc. Other minor 

I chanpa, princ:ipal.]¥ in terminology-, ~ indicated attar specific :references, 

belows 

a. Ohapter l 

' Parall"aph 1 - Delete. , 2 - On line 5 change word "assigned" to read 

"alloc1ted•. 
...... _ - ~-! 

. • 

· b, Chapter 2 

.3 - Delete. 

4 - Delete subpara.graphs a, b, c, and d. (See paragraph 4 of this correction sheet f'or current 

definitions. ) , . _ 5 - Delete. (Sae paragraph 5 ot this correction sheet 

for a list of current ~upplementary references.) 

(1) Section I -

' Paragraph 7 - Delete. (See paragraph 3a ot this correction 

sheet.) 

8 - Delete,} See paragraph 3b Dt this correction 

9 ~ Delete.) sheet. , lO .. Change first sentence to read "Signal com- .. munication personnel may be directed to aasjet 

is signal intelligence and communication 

security activities in addition to their 

;:1igDal communication duties. tr· 

11 • Delete. (See paragraph .3c or this corre.ction 

sheet:.) 

12 • Delete. 

(NO'l'E"k The information contained in paragraph 3d 

or thi~ correction she.et should be added to Section 

I, Chapter 2, immediately following paragraph 14.) 

(2) Section II -

Paragraph 16 • Delete subparaf.-raphs b and c. (See paragraph Jc of this correction sheet.) 

17 .... Delete.. (See paragraph .3e or this cbrrection 

sheet.) 

16 - Delet~ subparagraphs e and g. 

(.3) Section III - ~ilB.nge title to fe.&d "THEATER ARMY SECURITY -~(·EHCY. II 

--- Parag"'rpn 2&. el'lte (See po.l'agraph Jb or this correction •,liq~ t..) 

26 - JG lu1 ".l, (Seo paragraph ,;r of this correction 

.-1'" '3·~1 • ) 

/ 28 - lclete subparngraphs' b and g. 

29 - :Oc..li?te subparagraphs d and f. Ohange. word 

•:.Army" in line 2 or subparagraph g to read 11~honter 11 • 

JO - Change first two sentences to read "This sub-

' section performs a limited amount or origin!l 

cmtanalysis, It is ·dependent upon Army I 

Security Agency, War Department, tor assi"stance in the solution of themore complex . ., . . · 
........ 

a. Chapter 3 

REF 

\ 

enemy cryptosystems.n Add the following subparagraph: . 11 0. Cryptana1-ysis ot simple field 

cmtomtems. n ' 

(Na.rE: The intormation contairiecl in paragraph 3g 

ot this correction sheet should be ac1dod to Section III, Obaptor 2, immodiatel.7 tolldlring para- graph 30.) 

(1) Section I -

Paragraph .31 - Delete sontences 4, 5, and 6, and substitute 

the following= "Radio intellinnce companies 

are allocated to vo.rious commands as~reauired." 

32 - Delete. I 

35 - Delete. (For i=if'ormation on communication ' 

security pro~odures and objectives see 

TM 11-469, Commu.~1cation Security.) 

(2) Sec"tion'II -

Paragraph .3~ - Dolete. (See paragraph 3h ot this correction 

sheet.) 

(3) Section III • 

Paragraph 40 - In third aontonce, cha.nge refeJ"enco to 

"Assistant Ohiot ot Start, G-2" to read 

"D:f.rector of Intelligence. War Domrtment 

General Ste.ff • 11 

d. Chapter 4 (See paragraph Ji of this correction shoat tor general · comments on this chapter.) 

(1) Section I - -

Paragraph 50 - Delete. 

51 - Delete. 

52 - Delete. a. 

53 - In subparagraph -2;' c'ha.nge the 1'.lferenco to 

"enemy equipment identification ott:!cer11 on 

lino 4 to rone 11~Sccurit1 Agencx liaison 

officer." Dolo+.e subpo.ragre.ph b. 

54 - Chango first sentence to rend "Tho .ArmY 

Socurit1 Agen~t.J.jg!son officer to whom 

captured cr;rrpt~~P.ls are reported will 

assign an-of~~~o~ ~~mnke a st1ldx of the 

captured l!fll.0?':1f!:_n1.i to wcmro a dgj..l!,g 

report with suffi~ient copies for distribution as roguired. 11 ' 

, 
55 • Change reference to "enemy equipnent identification officer" in lino 1 to read 11li.rmy 

Security ~qqx_linison officer." 

56 • Deleta subpara~"T'ap.h b and substi tuto the following: ".P.s. ';°t=>-1~!.! Socuri t!Z.,_;!K2,.IJ.QX 

liaison offl<:...c~lJ report to ~ne ~irector 

ot the Then~~-~i:'llll, SeclJl'ity Agonc~ho 

Director of tho 'rh~m ~ .. er Ari§" Secur .. 1;.Y Js.goncy 

will direct the_1!!.1lizntion or dispo~ion of 

captured cryptom~ter10.l in accorrl!l.nr.e with 

j.nstructions from tho Chiof, .Army Security 

Agoncy, ilar Do..l!Y'~·" 

57 • Doloto. 

59 - Chango the reference to "enemy equipncnt 

identification officer" on lino 6 to road 

"Director of the Theater Al"J!!.Y Security Agoncy.n 60 - Delete subpnrngrnph a and substitute the following: a,, Intorrogc.tod by t}ie Army 

Socuri ty J~gency liaison officer to a.μ,gmont hit 

report nnd to devise for botter operation and 

utilization or tho caotured oguiJ!DOnt. 11 

61 - Deloto and substitute the following: 11.fil.. 

fflO'l'a!'YPES TO THE CHIEF I i.RMY SECURITY AGENCtH 

The Director of' the Theater Ar!!!y Security 

kgenox or tbe sor.ior Armx Security AgeqSI liaison officer ~ill, upop receipt of enemy 

_cr:mt91DAtorial, send' twG> prototypg sets to tho 

Chief, iq1aY SE>curitx J .. gencx bx j;ho quickest 

mgnns of nvailnblo trnnsportation. or r~, 

as mg.x be required• The ogμimgnt should ~ 

-.~ant AFI two shiments rnther than as a single 

sbi;mont. If only one i~em ot a txpe is 

captured nnd it is to bo" sent to tho Chiot, 

J.rmx Security .. lgency, it should be sent immedi;tel,y, not wsiting for n socond pr~~· 

As s00n as anothor is captured, the second. 

Jtem should QQ._ s~~, 11 

62 - Dalcto co.ption n...id first sentence. Substi• 

'Ute tho following: "62. INFORMl~TrON 

R!QUIRED,--Tho follO!!!..ng factors will b~~ 

pidcred in ~ho ro1'9}'..:Lforwardod to 1:.ho 

Diroctor of t.he Thou.!Q;r Ar!!ly Se"-.~UI Agency 

or the .Chio!', .Arn.y SocPrtty .. :t:gency, Wllf 

Dcoortmunta" ' 

e, Chapter 5 (See par~graph 3j of this correction shoe+, for general 

comments on this chnptcra) 

(1) Soction I -

Para.graph 63 ~ Dolcte nll oxcept tho last sontonco of tr.is 

paragraph • .. 
\ .. ... e REF ID:A6556 .. 

ParagralllJ. ~ : ~ (See •• , of this correction 

66 - ) sheet.) 

68 - Delete all except the, last sentenc.e of 

this paragraph 

/ 

(2) Section III • 

Paragraph 72 .:. Delete first sentence. Change second sentence to -read "~Q2P!,m,tion With exi~.!lil: 

civ.il:lap fac~ill!Ja iR not posej,Ae_~:! con~ 

SeauentlY a 19..L'",.&e_forc.·e Of Signal lJ.l°telb.gence 

and' COJIDlUniceticn recurit:r monitoring ae1-

sonnel "Will be reguir@d.n 

t • Appendix I· - Delete. A1ao delete references to this appendix 

which fl.ppear throughout Fii ll-35. 

I'• Appendix II - Delete. Al.so delete retrences to this appendix: 

which appear throushout :na: 11•.35. 

3. SUPPLEMENT.ARY INFORHATIOH.--a •. Gener.al.--The Anq ~ecurity Agency 

waa eatablished by War Department directive on 6 September 1945. It is composed of all ~ignal intelligence and caamunication aecurity establishments, 

unita and personnel ot ~he Army, except cl'JPtographic personnel of signal 

' 

and meaaage centers operated by other mllitart organizations 1 taetical i'adio I 

traffic coniirol. personnel., and the teahnical intelligence personnel who 

deal with captured enemy signal equipnent which is not IJf c:eyptologic interest. 

The Army Security Agency operates under the control of the War Department 

which is exercised through the Director of Intelligence, War Department 

General Starr. The reorp.ni!pltion of the War Department 911 11 June 1946 

(see ~ar Department Circular No. 138, 1946) made the Army Security Agency an 

integral part of the Intelligqce Division, War Department General Staff. 

The Chief, ArmJ Security Agency, War Department, is charged with the ac- • I 

compl.iahment ot the signal intelligence and communication security missions 

ot the Army. (This information supersedes paragraph 7 of Section I, Chapter 

2; n i1-35.) 

b. Theater Army Secur1tyAgenc1es.--In each theater at operations 

t}i.ere is a Theater Army Securit,Y Agen1m1rr•s the theater commander ln 

s I ~ ~ 
"& • ' .. • 'REF ID: A6556 • 

dTIGTEe 

aignal intelligenco and communication socurity matters in much the same manner 

as Headquarters, .1"\rlny' Socurity J.goncy, aervos tho War Department. 'l'heator 

Army Socurity ~\goncies are similar in organiza.tion to the '1rr Department ' ~ 

Agonq but o~ a reduced scale .... The scope of tho theator ai&ncies' .activities' 

are determined by the local tacticnl mission.a and tho signal intelligenco and 

communication aecurit7 functions which Ul' bo performed for tho theaters 'by the 

' 

l..nJ7 Securit7 JLgoncy, rnr Jlapartmont. Theater .. SocuritJ' Agencioa bavo at 

I -

their diapoaal various sipal 1ntelligence and commlm.ica.tion security organiationa which tho7 •7 allocate to subordinate comiands within th& theaters to 

perform local llisaiona. Some or these orgnm1oaT.1ons may be retained in a 

general reserve for assignment as tho milito.ry s::.tuation clictatas. Other units 

\ 

may bo roaarved f'or the pertorance of'o missions"" for the theater headquarters. 

Be.low theator lavol, and for certain independent comnumds under the War Depart- ~ 

ment, the signal intolligenco and cOllllUDication security activities are handled 

'bJ' .~1"JB7 Socurit7 •geii.cy liaison dota.chmenta. (:rhe above lntormtion replaces 

paragraphs 8 and 9 ot'Soction I, ari8. po.rngraph 24 of' Section III, Chapter 2, 

r.11 n-35. ) 

c. Signal intelligence and'communica.tion socuri'f11' organizationa.--

The. Signal Radio Intolligonco Com.pc.ny, T/O 11-77, referred to throughout 

111 11-35 is now obsolote. Roferences to T/O 11-77 should bo deleted. Replacing the Signal. Radio Intelligence Compnll1 aro t1'8 toJ:lwing orgonizations: 

... 

(1) ,;r.ir typos: .. (a.) Radio Squadron, Mobile T/O & E 32-J027 (n sigll'Ll 

intolligence orge.niso.tion) 

(b) Radio Security Datnchment, Tio &: E 32-952 (a cOJll'llunication security monitoring organization) 

6 
' . . ' 

.. REF ID: A6556. 

(2) Ground tJPBSI . ~SJRICTEll 

(a) Signal Service Company, Radio Intelligence, T/0 &E 

11-SOO* (a signo.1 intelligence organization) 

(b) Signal Service Compe.ny, Radio Socurit;r,• T/O & E 11-50~ 

(a communication security monitoring organization) 

It will be noted that the communication ae~urity monitoring functions of the 

old radio intellipnce compan;r (T/O 11-77) ~ve been divorced tram the signal 

intelligence functions. Tho two tunctiona art\ now perf'ormed by the separate 

"' I 

orp.nize.tiona indicated in (1) and (2), above. The tour types of' organize.- . tiona listed above are the be.sic inf'ormation gathering units of' the .'lrmy 

Securit7 Jgonc;r. Through those "QDita tho Army security Agenc7 obtains moat . of'~the material tor its stud;r. In addition, thore IJ,re smaller units which 

' havo more restricted functions such aa cryptographic production, distribution 

I 

and.accounting teams; laborat01"7 toBDS tor the empl011D9nt and dotoction ot 

secret inks, microphotographa, and diaguisod witing; cryptoequipnont mainteno.nco and repair' units, and wire intorcept teams. famT Securit7 Agency 

units and pers01111el a.re allocated to various commands in tho types and 

I 

quantitiee required to meet the local military situo.tion. (The above int'orma.timi supersedes paragraph 11, Section I, and subpe.ragraphs b and c of' 

paragraph "16, Section II, Chapter 2, FM 11-35.) 

I d. Coordina~ion ot krmT Security agonc7 Activitiea.--Overall 

coordination at all J.riq Securit7 Apnc7 units is accom,Plished b;y: tho Chief', 

Jafll1 Securi t7 Agenc7, War Department, in dccordance- with War Dopartment 

policies. Complete coordination of' all signal intelligence and communication 

J1ecurit7 acti~tjea which com:arise the reaponaibilities at the A'1!111:/ SecU]:"i,:tJ' 

* Portions at T/O & I 11-500 which pertain exaluaival.J to J..rm;r Security Agency 

f'unctions will be republished shortly in T/O & E 32-SOO, Communication 

Reconnaissance Organization. 

7 
... , . 

Agen07 ia necessary bec~uso or their complementllry and interdependent nature. 

Coordination is effected through a .special tochn1cal channel which exists to 

facilitate complete nnd rapid exchanges of sigml intelligence and communi'la- .. 

tion security intormo.t:ton. Thus the f'ull power of eo.ch,o.ctivit7 is exerted 

to etf'ect improvements in the other. llu:imum economy is achievGd by eliminat-

-ing duplication of' effort 11nd es~blishing common standards ot performance. • I 

(!he above inf'ormation should be added to the end or Section I, Chapter 2, 

111 11•35, :lmmediatel7 following paragraph 14.) 

e. Duties ot the Chief, Army Security J,,genc7, ~ar Depe.rtment.--The 

Chief, Js.rf1J7 Secrurity J\genc7, War Deportment, is responsible to the Director 

' 

ot Intelligence, Wal' Depnrtmont Genernl Ste.tr, tor the accamplishment of the 

signal intelligence and communication security missions of' the h.rrrry in o.ccor- . dance tdth directives f'orMul.o.ted by the War Department. He coordimtes the • 

' 

operations ot all Army Security Agency units and personnel of the ArlD.y. He 

maintains liaison witb other groups in Intelligence Division, Yar Deportment 

./ 

General Sta.rt, which are concerned with tho :£'unctions of tho Agency, and with 

the Signal Corps, Navy and other governmento.l dopc.rtments, o.nd rith friendly 

f'oreign gov.ormnents as directed by the War Depe.rtmontc He is the techn".cal 

advisor to the Director of' Intelligence on signal intelligence and communica~ . tion security matters which 'lonstitute the responsibilities of' tho .4rrq 

Security Agonc7. (Tho o.bove inf'ormntion supersedes pnmgraph 17, Section II, 

Cha.pter 2, Fii 11-.35.l 

r. JJutios ot the D:J,rector of the Theeter /i.rrrry Security Agency.--The 

Director of' the Tho~ter-Army Secur.ity ~gency is rosponsiblo tor tho suc=~ssf'ul. 

nccompll.shment ot the signal intelligenco D.l".d 'lOmiD'UJ'}.ication security mi,Ji"ions 

ot t!\8 theo.terwhicn are received in the form of general dir'ectives from the 

theater commander. 

a 
A REF IJli;~if? • • lllWY/ D UIV • -

.. services; acts as technical advisor to the theater commander in signal intelliience. and communico.tion J11ecurit7 matters, and: coordinates· the opera'tions ct 

all theo.ter alloco.tod Araty Security Agency orgc.nizo.tions in o.ocordance with 

if>haral Wo.r Department polities and theater policies formulated •it.~in th.Ai: 

Nmnework.. (The above inf'ormn.tion supersedes paragraph 26, Section III, 

Chapter 2, PM ll-35.) . g._ .Arm;J' Socurit)" &gency operations below theater level. --Field to~·ces 

subordinate to o. theater beadquart~ra, down to and including division and com- . pnrable heo.dquarters of air forces, will be served by Army Security Agenc7 

liaison deto.chmenta and such signal intelligenco end communication sscurit7 

units and personnel as 111&7 be necep11Dr7• Tho prlmo.ry mission of each J..rm)" 

Securit7 AiellOJ' unit is to support tho command to :which it is allocawd. Missions are ,assigned bl the local commander. The functions of' the ..!rm?" Soou!"it;r 

.Apnc7 liaison deto.chments are to adviso loco.l cominaniiers on signal inteJ.li-

.. genco o.nd communication security mo.ttors; proper employment ot the Ar1r.y Securit7 -

-'gency units allocated to those c~dors; plan and direct the employment ot 

J.rmr Securit7 Agency_ units, and coordinate their operations .Pith thdse of :;11e 

sisrml intolligence and communication security 1.U'rl, ta at the next h:f g11er ~nd/ o~ 

lowor levels. (Tho nbove illf'o:rmc.tion should be added to Section III, Chap"tsr 

2, Fii 11-35,. :lmmodinteq following paragrnph 30.)' 

I 

.. h. The intormo.tion on nuthontico.tion &)"Btems and procedures conta!nerl. 

in Wnr Depirtment Train1ng Circular No. 74, 1944 (as amended by 'RD -TC No. 33, I.-• , 

1945, and WD TC Ho. l, 1946) replo.ces that uhich is conto.inod in pire.g:o.lph "'9, ~ I 

Section II,. Chapter J, Fii ll-35. 

i. Insofar na captured enemy signal intelligence ond communiea.t.i'>n 

securit7 equipnont and documents are concerned, the ;.:rrq Security J\gency 

9 

' 
\ ... la. II •_. 

~ 

I 

operatea a service similar to that described' in Chapter 4, ftl 11 ... 35. 1'he 

Lrrq Securit7 .4genc7 service ia concernod onl.J' vi.th crypto1Qg1c itOJ11s. 

3. J%'lflT Security Agenc7 otters assiste.nce to censorship b:- e:z:ar.:•n1-.2 I ' > 

. documonts 'for traces ot invisible writing., and aicrophotog.raphs and in t'lu 

• 

aolution ot open codes, shorthand writing and unauthorized Cl'"YP"~oa7et~ms~ . . Except insofar as Arorr Securi tJ" /,.genCJ' tacili ties mq be us'ld to :nQr..i .-.c-r, . 

. 

I electrical oommunications over which literal, voice ~r tac,imilP t:rs"..nJDli~sl'Ul& 

are pa.saed,'tbp censorship activities doscribod :in paragraphs,64, 65, au4 66 . I 

or Section I, Chapter 5, Fl ll-3,5, lire t~ reaponsibiiit7 of cthor i:itelli1ence organ11ations or ot 'the operating agencias, themsolvp.s .. 

4. Detini tions. --The 4tollowing are current. detini ttons tt>':':' t.:.rn~ used 

in th1a correction sheet a:nd in FM 11-351 ' 

a. ~l in+.el.1igenu - all intelligen::e durived from. the stwi.y "~ 

' radio tra.namiasions and other commun1pe.tions. I 

b. Communic1_tiougs_ur!ty ,. ~e prota-::ti::n -esalt:!.ng from a.ll 

•aaurea designed to do!lJ' to mm.uthorized persons ir.itoI'l'lt!.+1 .,r of' val"JO r1"'i'°"" 

might be derived trom co1'1111ouniQ&tions. 

c. Cl"YR;k>@!.quri~ - tho.t component ot commu"'lica.tion oocurit)" "J'n.1.m 

results trom the provision ot tech."1.ico.lly sound cryptogro.phic sys-toms and 

I 

t:trair proper- use •• 

d. Transmission se::mritY •• that co1:1.ponont ot comunicatiol) securttr 

which results tram all meo.sur~s designed ~o prote~t transmissior.s :ram in--

torception and tratf'ic ann.J.ysia. 

e. Pbraical securitJ' - thn.t componont or co:mnnnicQ.ti:m securi~y 

which results tram a.11 measures nacessnry to so.f'eguard t•lo.asifie:i camr:U&'l" oe.- , 

d \ . tion dquipnent D..D .:material trqm access thereto b,y' unauthori~e:i pEtraons. 

10 
t. CryptologY - thnt branch or knawlodge which trents of the pr~-

duction, use, and solution ot the means and met.lt.ods' ot secret icTDm":n:h:.a-: .. c"'t. 

I 

means and methods of ren:h.r'L"'lg plain text un:l~:' .. el H.g:::.ble n..""!Cl -:a~~m,.-a?"Ung • .?:.· 

1ntolligible t.e:~ int'l i'lt.e!ligiblo lnngunge,,or the npc~ir~:t .. 'l:r. "'heJe0.,..1 

I 

into .fntelligibilluy ~nc1"3rptod literal, spoe~h an~ fo.csi~ile tra.~"l!lli~siona I 

without kncmle.dga cf the aysi.om o.nd/or tho speGific key employed. 

I 

i.. Traff:::.f...:"J.!.~ollY.V..! • thl't branah o! s1gno.l intelligen~e a:ri.n1 ysis 

which deals with !:.he stJiy of t.h.a oxt~rno.1 <-ha.i•ectoristias al signa: co:nm::.mi• 

ca1;ions o.nd rol.ntec ra..1.to-ials for tho purpose o.r obtaining iDt'C'::-nu- ..,~r.:i r .:n·• 

earning the argan!zatJ.on and operntion o£ a communication system. 11'his iZ?.-

tormation is used (1) as an nid to ceypr.annl.y"sis, (2~ as a basis fo-:: ~eiw:!.ng • 

doductions and inferences of veluo ns intelligence even in the absanco cf 

specific knowledge of the contents of tho mossap, and (3) as a guide to 

etf icient intercept operation. 

j. Interoeiztion - the process of gaining possession of commu.'li~ations 

intended tor o1*io::"s either by copying or recording or by other moans. 

k. J!.QnUp"l"ins - listening in -on one's cmn stations or on statione 

ot triondl.7 forces, with a view to minto.ining security. 

1. ~n cq_:}! - a. cryptographic syetem using external text (envelo~ing 

text, p.pparently i:ri..nocent} to hide o. secrot toxt. 

s. Retorences.--Supplementary- information Jll8.7 be obtained trom the following: I 

TF 11-205 

TF ll-2044 

/Jl 380-5 

\ 

Safeguarding Militnry- I:if'ormc.tion - Cryptographic 

Rad:::.o T~a~Jrnl~sai~n Security 

Se.f'oguar~ Inf'ormation ti~.. I I !.1 

11 
• l'1 • ...... T' • 1-A I 

TM 11-469 Communication: Seourit7 (reterences in this mnnu:il ~ the 

"Chief Signal Of'ficer0 should bo changed to rearl "~ 1 

Jg'lr::£.!~ut±l:r Aga..n2r" 1 and 11 RPS!C~ to 11!2'l~:f~'·. ) 

Tll lt-484 :ihsmont.nry Milito.17 Cryptop-npb1' 

TM 11-~; J..o.vancod ~ l " ..tGJ.ey' Cryptogre.p'1y 

WD TC 74, 1944 : .. uthenti<"ation syst~ms (/iDJ.onded' by: WD TC .33s 1945. 

Si3C'tion II, J .. uthe:riticc.tion systems, and W'1J TC 1, 19~, J..uthent1cat10!') systems.) 

6. Charts of' the organisation ot J .. rmy Socui·:lt.7 J .. genc7 at War Depart11&o:it 

level and in the theator may bo constructed f'ram the information conta.in.)d in 

Seci;ions II o.nd III, rospoctivol.y, of' Chnptor 21 Fii ll-35, as amended by this 

correction sheet. Charts so constructed will be essontiall:y corre .. t. ~e 

emct details of' orgar .. izo.tion cannot be dissamirmtad for securit7 reasona .. 

• 

) 

12