25 November 1953 

].. Regulations at present in force (00. 2/7 (Pinal) and STABD 474 as amended by 

~ 1508, 1535 and J.588) ensure that all COSMIC telegrams am all NA'l'O 

TOP m:cRn and SBCRft telegrams are eneyphered in cr;ypto87stems authorized by the 

StancUng Qroup. But all mtions ot 1IATO are also originating and transmitting in 

their own natioml CZ"1'Ptosystems a quantity of telegrams both civil and militar,y 

vhich, although they' are the private concern ot the nation in question, must be 

expected to contain int'ormation which a:ttects NATO as a vhole and the loss ot 

which to a non-M'l'O nation harms the security ot NA.TO. 

2. hrther STAID 1,.74 allows Mro telegrams graded COD'IDEllTIAL OR RBS'DlIC'l'ED 

to be encr,ypted in national systems, am it is highcy' undesirable that inforation 

ot such gradinp should beccllle available to mtions outside KATO. 

3. '1'be stancJ1 ng ClroUJ> therefore feels considerable concern at tbe potential danger 

to the aecurity ot llA1'0 which~ arise from the insecurity ot the national ~mtcations ot 1Dl1v1cl18l. nations: the insecurity of one can endanger the security ot all. 

4. 'l'be Standing Croup bu bad prepared a :pa.per enumerating ezamples ot cryptographic 

and ccwnmtcations practices and procedures vhich end&Dger security. This paper ia 

attacbed at Appendix A. '1'he Standhig Group requests tl:Bt each member nation eneine 

this Jl9PeZ' and take action to ensure that its own N'l!lllm1cat1ons are 1'ree troll the 

practices &n4 procedures •ntioned therein. 

5. further the Standing Group requests that each IA'l'O ration will designate or 

eetebUah a Cagmmtcationa Securit7 Agency vhich shall be authorized to comnmicate 

on ~mtcatiOD aecurity •ttere both civil and mU.itary direct with the Standing 

Group Camtm1cations Securiey and. Eval.mtion Agency W&shi.Dgton (SECAB} and with the 

Buropean Securiey alld lval.uation Agency (Btm:C). 

6. '1'be Standing Group invites any member nation, vhich requires advice and tecJmical 

uaiatance towards the improvement of the security of its national cryptographic and 

e<mnmications practices aod procedures whether civil or militar,y to app]¥ through 

their ec-untcations Security "8eney direct to the Standing Group Ccmaunicationa 

Security and Evaluation Agency Washington. It m,;y subsequently be found more convenient tor SF.CAB to arrange for discussions arising out ot this first approach to 

be held with EtEEC. 

SECRET 

Declassified and approved for release by NSA on 06-04-2014 pursuantto E.O. 1352a 
..-· .. - - ...... 

I. UDHCIPBERED CODES. 

~F~:~~2~~ l(Qr ~~tttt!;r ~ 

l>RAFT 

LIST OF EXAMPLES OF DANGEROUS 

CRYPJ.'OORAPBIC AND Ca.MJNICATIONS 

PRACTICES AND PROCED~ 

25 November 1953 

l. thenciphered codes are totally' inacceptable in diploBILtic use "ror transmission of classified inforDBtion. They are only acceptable for Armed Forces C01111Pmications vhen it ia not considered essential to naintain the secur1ey ot the information for more than two or three ~s .from the introduction ot the code. It follows 

tba.t such codeG must be cbanged at.very frequent intervals. 

II. .AJl>ITIVB SYS'1'Ble 

2. Aa:I additive (or subtractor or minuend) system is dangerous UDleas special 

precautions are taken in the construction ot the additive itself. ~ procedures 

tl:at ~be regarded as "special precautions" are deceptive as to security and 1l8:f 

EO 3.3(h)(2) 

PL 86-36/50 USC 3605 even in themselves create weaknesses. 

5. In Senerai·,, pol.yal.pbabetic substitution systems whether actually additive 

in :nature or not, are like additive systems and are subject to the same dangers. 

III. NOR-ADDITIVE BAND S!'S'.l!.IHJ 

6. There are D1U:J¥ baDd systems of encipberment tbat do not employ sd.ditive. 

Very tew of these can be 8lBl'&nteed to be secure, even though they my be very 

complex, applying both substitution and transposition to code or plain languBge. 

1· Machine ciphers vary greatly in the amount of security they afford. 

lailure to observe in every detail. proper instructions tor operation DE¥ lead to 

compromise even vith the best m.chines. Others, such as the well-known Bagelin 

TOP SECRET 
... 

REF ID:A522502 

SECRET -11 

25 Bovember 1953 

~" ( aee :para 8 beloll) are insecure unleaa precautions are taken over abd 

a1Kwe thoN nccmaeDded by tbe -.nuracturer. Others, again, are buicaJ.l7 insecure 

amt aboul4 in llO c1rc\88tances be uaea. 

8. Special attention is clraVD to the dangers 1Dherent in tbe use ot tbe lll&elin 

"Cz,ptotelm:J k" whines ot t.he c-aeriea: 

a. 81.Dce tbe encipbiermer.&t ia eaaent~ b1' ad41t1ve, it tollowe t!at it a 

•••• setting is used .mre than once the key can be recovered on the overl&JJ; 

a •11tcle lll•take by an operator ua1Dg a message setting a eecond time can tbua comproo 

llUev the-·-ebiot" setting. 

b. !be additive pnerated b)' the acbiDe is never ~ ra:adcm add tbere ue 

ciremetances in which this ~t can 'be used to recover tbe -.chine setting, wen 

tboup DO weap setting ie repeated.. 

c. With proper precautions this imchine can give Yfllq good securit.7 tar a 

lild.ted. UDlmt ot trattic, but in view ot the D1lllber Of d1:tterent dangers that CUI 

ariae iJl var;y1Dg coDClitione at uae, tor which it ie illpoaaible to legislate in 

~ • ...,_. mtiona vbo wish to .a use ot t.be "Crntotelmikn an eapeclall,y 

wp4 to consult SECAI. 

Y • 'l!W&CI88ICB s.acmrrt. 

9. C1;pben, boftYer good 11141v14\Blly, are not enough to ensure ~micationa 

MC18"1Q'. TnDsmisaion techl'liques aid message t'onata can in thell8e1vea provide 

cone1ter.b1e 1ntelllgence to a trattic am.Jyat. Although there are practical 

l.1111.taUom, the 14-1 to be striven tor is tbat the trattic neither ot' azv tne 

(e.1., mftl, air force, etc.) nor ot at\V' nation should. be diatinguisbable by 

exterm.l cbuacteriatics. Again, intelligence can be pined b7 atuil¥ ot tbe 

or.,ai.•t1on and procedure ot radio networks and by wse ot radio direction-tincttag. 

ID aiw cuea, especially in A:rme4 rorcea ~cations, a aldlltul eDellV' can 

obt.atn valuable intelllgence b)" collation ot apparent)1' uniDf'orative ••eaae tats. 

It toll.on, therefore, that f'ull C<:mnmicationa securitJ' A ma that special 

precautiona be observed in such attere as the Juilicious ellg)lo,vment ot indicators, 

the selection ot call signs and ot frequencies, radio proceclures, aJld. the reatrietion ot the uae ot plain l.&Dguap. 

2 

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l9P 8BSM! CcmROL m.ta:m s J-f'l-z.~ I 

COP! X' (;I 2..- O PAai!lt't" COPl'E.J' 

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