:. 

-

ii 

I.. 

REF ID:A57232 

SECRET 

8'89&! 

.l8-6{2) Seour1""1' ot .D'SA. oomm.tmioation cirouita 

I lfay 50 

l. The attached memo f'rm. AFSA-OOB. dated 14' April 1950. i• fdrwarded 

tor your comment• and recomme:ndation. 

ea 1 .AJ'SJ.·lS 

/•/ s.P. OOLLIIS 

s.P .. OOLLIIS 

Colo:aol Signal Corps 

Deputy Director• .AlSA 

J'ronu AFSJ.-04 Dates 2S JIA.Y 60 Comment 'lo. I 

Xr. Oorey/428 

1. Surnilla.noe ot communioat1on9 intelligezma aotiviiii•• ha• been largely 

limited in the pa.at to oocas1o:nal apot-ohecka because ot limitations on per•onnel 

available for euoh tuka and baoau11e ot the tremendous 1co:P9 ~volved in a 

thorough analyaia. A rough eatimate indioate• that AFSJ. oommunioatio!ll represent 

at ledt 76-80 percent of tbe total enorypted :msasage volum.e ot the Armed :roroe1. 

Included am.011g a.ctirltie• ool:lduoted reoentl,y along thi8 line ares 

a. .A.pproxima:tel;r a ;year ago,, om traf'!'io aJJAly•t 1'11.8 uaigned the tuk o~ determining t,ypo• and amount of iJJt"ormation available through external exam.ni:nation ot .A:rtlly- Security Agena,y trat.f'io. Cowrage wu limited to AJJJ.. tra.ttio appearing cm J.C.All oircuita whioh were \mder •urT•illance tor ordinary seourit;r monitoring 

purpoae1. Do formal report 1llUI rendered but evidence 11'&8 au!'tioient to imicate 

that the tollsing oonolu•iona could be 1ub•ta.ntiated1 

{l) That the peculiar oharaoteriatica ot intercept tratfio make 

it euily id.entitia.ble am that axw- attempt at oon.csealment 

would haw to be of' 1uoh draatio nature u to make praotioa~: ':" 

\ility que•~icmable. 

(2) That it i• probable that the ext.naive WI• ot radio comm.unicatioDll tor .torn.rd.iDg of intercept i• unjustified.,, and that 

proper aegz"•gation and ume of courier airoratt would result 

in reducing radio traffic volume to auoh an e:rtezrl; that oona:Lderation .teuib1;r migh:t be g:S:n:n to application ot tran1 ... 

ld.aaion aeourity mea•ur•• to reduce recognizability. 

{I) !hat the .A.nz1¥ Security' J.Cenoy :tielcl intercept organization 

{i.e.• "Order of Battle Intorma.tion.•) could b9 reconatruoted 

with a minimum. ot effort. 

(4) !hat aom "•peoial" operating practice• whioh tend to further 

1egregate intercept trattio might be elilli..nated without im. ... 

peeling trattio ha?Jdline;. 

__.-:--~----:--------:-:o"~----:----:"~~-S,,,..,...,....,E_C_R,..,....-ET~~i\lP 1 

eclassifi ed and a roved for release b NSA on 05-16-2014 ursuant to E .0. 1352 
• ,+· 

;, 

\ 

l 

~l 

,~, 

•t 

'\ 

~,F ID:A57232 

SECRET ~ 

Subjects Seour:l.ty of USA oommunioation oirouit• 

.AJ'S.A.-04 Dv.te a IS KAY 60 Oomnent lfo. I 

Kr. corry/416 

(5) That o!rcu1t di•cipliD& and operator •~tioie.no7, although 

approximating the O'V8rall A:rtq lewl. could. 1tam oonaiderabl• improvement. 

(8) '?hat ••t&bliehment ot a procedure whereby th• •eourity monitoring aotivitT might insure that correotive action i• taken in 

oalell ot JIUl.jor tranall1••1on •eourit;y rlolationa, would be 

bsmfioial. 

(7) 'fhat. um.er certain airoumata.ncea, it u possible tor an enem;y 

'to determine apeoitio intercept target• by ou•tul. padding ot 

hi• trati'io nlum.e and oloae ana.1:1111• or Tolume originated b1' 

aertain interoept atation.11. 

(8) !hat. 'b1" obaenation ot "YOlme origi:mt1ng in certain area•. 

it i• po••ibl• tor ge:ne~al u-.u ot: emphui• tor interoept 

purpose• to be determined. 

b. Within the past yeu and • halt, Op-20!X oo.nduoted a •urTeY ot Oommunioat1~n SupPleJ118ntaey .A.otiTiV !ra.1'.tio •iJnilar to that carl'"4-6d on~ Anq 

leourity" .Agenoy. The conoluaion1 were adequa.te1 not oJ!l,y wae "OJ.·der ot Battle 

ID.tormation" obtained but th• olu•itied call •igm and delinry group• in uae on 

the aupplementaey mt were recOTared in full. 

o. · Station• origiuating intercept trattio have been • ubjeot to the •a:m.e 

T1ol&tion,, com.promise,, and tr&ttio TOlum.e reporti:n& procedure• a• all other Armed 

:rOl"cH actiTitiea,, thua providing om mans of' oontiuui:og aurveillance. It •u in 

aonnaotion with t be carr-,ring out or this prooedure that the recent deoiaiona oonOer".D.ing the imdequaciea ot CSP 1615/SIGGUll were determi:Ded. 

'd.. A progr11m. to aToid uaooiat:l.on ot direct oomeotion bettreen certain 

•oritiotl area" Special 8eourity Otfioer• and Arlington Hall Station ha• been in 

etteot tor aome time. Thia program. inTolvea oar•ful oontrol ~ external &ddreHing 

ot eommunioation• and,, in •ome oa••*• uae ot di•gui•ed o:ryptographic •1•teJ11. indioa .. 

tor•. 

•• Spot-oheok• ot me••age bu.dings ~ decrypted tapes have been made at 

irregular intervals in the put tor imicator deptha and tor oarel••• praotioe11 in 

indicator •election. 

t. Re-evaluation ot orypto-•eourit,y provided by ASAM 2-1 baa been i:n 

proceaa tor the put ••veral 119ek•• An a.iitempt ia beint; made to deTi•e a one-time 

t.y procedure acceptable tor intercept •tation uae. 

SECRET. 

-t· 
l 

r 

ii. 

l 

. 

r 

"'" • 

--

! -

= 

REF ID:A57232 - -- .. 

SECRET 

IB9RB! 

flie Bo. A-8-6(2) 

!Ot .u'U•OOA. Subjeot1 Security ot J.FS4 comm.unioation oirouit• 

J'romr J.1SA.-04 Dat•s 23 Jll.Y 60 Cmnment llo. 2 

Jlr. Oo:rry/4=26 

!. It i• believed that a more complete and more thorough security analysis of 

Ali'S4 communioations is (eairable,, to obtain f'aotual data to aub•tantiate concluaiona 

preaented in paragraph ia bove • a:od to provide a planned clleck on cryptographic operating practioea. !him will require aome assistance from USA-02. ' 

I. It ia recommended that the attached Di•position Form,, requesting as•i•tance 

frm AFSA-02,, be appro"Yed and forwarded. 

l l;l\01 

DjF from .A.FSA-04 to 

AFSA-02 aubj u above 

I•/ H.o. HANSEi' 

H.o. HANSEH 

Oapta.in,, U.S. Jla..y 

Ohiet,, Ottioe 0£ Seau.i:ity 

SEC RE~ 

---- - -