---· ~SEGRET °1~ Office Memorandum • uNITEo sTATEs Go~MENT 

' TO AFSA·C>C1! DATE 17 August 1951 

• FROM ~ o1: Staff 

. . 

, 

SUBJECT Report o1: the U.K./u.S. C<mann1cat1ons Securit7 Conference held 

in LoncJon in Ju17 1951 

The in.closures are forwarded tor JOV inf'ormation and retention. 

IDcloaures - 2 (bound together) 

l. COPf BO. 13 ot "Report to the 

Brlt1Bh Chiefs ot Staff and 

to the U.S. Chief's ot Sta.ff' 

of' the u.K./u.s. Canmm1cat1ona 

Secur1 tJ' Ccmf'erence Held in 

LoDdoD in J"uq, 1951" 

2. COPf RO. 13 of' R~s of' the Wor~ Parties (ICS/Wl/R tbru 

ICS/wl.2/R) 

A. C. Pi'J!:BSOI' 

Colonel, .Art1ller'7 

Acting Chief of' Staff 
BEPORT 

ot the 

U.K./u.s. COlmJllICATIOIB SEC1JRl'ft COIFERDCE 

BLD D LOIDOB D JULY, 1951 
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ms/f/R, Couy No: 13 

REPORT 

1. In their en.aorsement of the report of' the u.K./u.s. Ocmnunications Security 

Canf'erenoe which was held in lfashington in September 19.50 the British and the 

u.s. Cbiefs of' Statt agreed: 

"That there be annual canf'.erencea on tlBse subJects f'or the 

next four years to be held altemate~ :ln Iondan and 

Washington, the first of tmse to be mld :ln London :ln 

approx::lma.teq nllle months t:fme". 

2. In accordance 'lt'l.1ih the above directive tlB 1951 Conference was opened in 

London on 6th J'lll1' am closed on .}1st July. The following itans were aisoussed:-

On-line Cypmr Ma.chines. 

Off-lb Cypher Macbines. 

Replacement of' the c.c.:M:. by BRUTUS. 

Combat and IDw Ecmlon C:eyptosystems (:includ:ing Authent:f.oaticm). 

Kercbant Ships C:eypt;o systE111S. 

Meteorological Cyphers other than C:Lf'ax. 

Cif'ax. 

Cip'fm\y. 

Cypher Key Gcne"ra.t1.0I1. 

Secure Wrapping of CyplBr Material. 

I.F.F.: Security a.speots. 

-'• Reports of' t'he various 'W'OD:ing part:lea which discussed the above listed 

aubjects are held both by the Director, Aimed Forces Security Agenay, 'Wash:ington, 

and tm Secreta.r,,y, Cypher Policy Board, LonaDn. 

4. The programme of' the Conference :blcluded a full and :f'rarJk emhange of' v1en 

on all the items listed above, demonstrations of such equipnents as couJ.d be ma.de 

available, a:n.d a series of visits i;o establishnents concerned :In the research 

and developnent of communioa.tions security equipnerrt. 

I 

S. The major reocmnenda:tions of the Conference a.re tbat :-

(a) tbere be acmplete :interchmge of' all projected equipnents and 

teclmical information :1n the f'ield of ccmmmicatians security so tla t 

the u.K. and the u.s. ma:y oarry out operational and security 

evaluations; 

(b) there be visits of teohnic:is.ns as required and particularly wlmm-ver 

aI>l' equipnent is ready tor demonstration; 

(c) :in connection with the Brutus Cryptosystem:-

(1) there be no restriction on tbe level at which this system 

JllS3 be used, but 1 :lD accordame with i;he agreement between 

the British and the u.s. Qh:ief's of' Sta.tt, disclosure of the 

BRllTUS cryptosystem sbould be conf'ined to the appropr:ia.te 

authorities :In tm u.s., U.K., Cami.da, Australia and 

New Zeal.arid; .. 

/(ii) 

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(ii) the use of this system bl extended to L:lmited Canbined Naval 

Law Eobalon CCJ'!!D'Dmic.ations J 

(iii) A.F.S.A. a1'ld. C.P.B. detemdne the operaticmal prooedure and 

tbs rules for tbe pl\vs:l.cal safeguardillg of this system; 

(d) the U.K./u.S. J.c.-E.Cs. be asked: 

(i) to &tate what oanb:lned operational requirement exists for 

on-1.lne cypmr equipne:at; 

(ii) to def'ine the canb:lned requirement for Air-Ground aryptoayatems. 

(iii) to def:lne 1ihe canbined requirement for teleprinter facilities 

to be inoorporated 1n new o:f'f-line cypmr machines, including 

suph aspeats as the telepr:ln1ier alpbabet, keyboard am upper 

case facilities; 

(iv) to state 'llfbetber the "Personal Identity" reoogn:i.tion faoility 

in I.F.F. equipnent need be guarded by a.ypbar:l.ng; ~ 

(e) the next Conf'erenoe take plaoe 1n three pl'ases to be held consecutive]3 

:fn tbe fol.lawing order, to ensure the closest lJAison between the 

cammmioations plmm:ing staf'f's, the security experts e.nd tbs enginaers:-

(i) Keeting between cmg:lneering and security experts of A.F.S.A. 

and o.P.B. to ex.change detailed teobnioa.l in:l'omation am. 'Vi.en. 

(ii) Meeting between .h.F. S.A. and C.P .B. to detezmine engineering 

possibilities and security standards. 

(:lit) Meeting between U.K. and U.S. oamn.mications planning staffs 

and representatives of J •• F.S.Js.. and of C.P.B. to examine and 

define canb:lned operational requirements and, "lfhBre possible, 

to seleat equipnents to meet thmn. • 

(f) tbe nut Conference be held in W'ashington :In April or May 1952. 

6. Tbs ma.Jar reoannenna:ticms in pa.re.graph 5 above are subnitted for the approval 9ot the u.s. Cbiefs of Staff and of 'the British Chiefs at Staff. 

The detailed oonclusiori..s of the :lndJ.vidual darking Parties, as endorsed by the 

Conference, are being sullldtted to the Director, Aimed Forces Security Agency, anl 

to tm Oypmr Policy Boa.rd tor approval and further action. 

l?L.86-36/50 USC 3605 

Sis;ned: Colonel S.P. Collins, U.S •. ADJW. 

Cmil111an ot u.s. Delegation. Signed: I 

...,c_:ta,_....i-:man--ot-t .... Ee-u-.-x-..... ne ........ ie.,,..ga...,..,,..,.t=ion."""="__. 

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u.x./u.s. COJllJllIC.eIOBS SBCURift COIFER151C15 - 1951 

Reporta ot the Working Partiea 

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COPY NO; 13 

UK/UB Communications Security Conference 1951. 

on-Line Cypher Machines. 

Report of' ,/orking Party 1 

as approved by the Executive Committee. 

1. Tiie Jerking Party reviewed the on-line cypher machines, 

available and proJected, listed in paras. 3A - 30 below. 

2. The Working Party discussed tha possible operational requirements which the U.K. and u.s. Services have for such 

equipment and agreed that they appeared to fall into three 

- categories: 

A. Fixed Services {i.e. Synchronous exclusive 

point-to-point circuits) 

B. Network Operation {includi.ng broadcasts) 

c. Special Purposes {e.g. Hazardous operations, naval 

broadcasts, special missions, 

low echelon and combat purposes etc.) 

3. The ~orking farty considered that it was not for them to 

determine vhether there is a Combined requirement for equipment of this type. But if the UK/US JC-E~or other competent authority decides that there is such a requirement, then it is reconmended 

that the requirement be met by selection from the equipments listed 

below in accordance with the circumstances of the case. 

A. Fixed Services. 

~ {i) If the requlrement arises 82!!• the only equipments which could meet it are:-

{a) 

{b) 

~'D'Daratus 5 u.c.o. No. 1. Synchronous device using 

one time 5 unit tape. Size = One 6 foot x 19 inch 

rack per duplex terminal. Gives traffic flow 

security. Now in production. 

Circuit MERC~Y. Synchronous 31 way permuting machine 

usin.g a 6 + double rotor maze and m~chanical 5/31 

converters for 5 unit co;o operation. Size = Twe 

consoles Elllu one 6 foot x 19 inch rack per duplex torminal. Nov in production. 

{ii) The following additional equipments should also be 

consiaer&d but qill not be av~ilablc for at least two years:- , 

{a) AFSAM 1{· A synchronous moaified version of AFSA.M 9 

using n nc 36 point rotors as a 32.wey permuting machine ~1th built in 5/32 conversion for 5 unit code ~peration. Gives traffic flow security and automatic 

message numbering. Size = Ond 6 foot x 19 inch rack 

per duplex terminal. 

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(b) ~illT~CB9fc A twin chnnnel synchl'on:)US system using sub iad~r cypher key derived from an electronic 

key generator usin.~ multi-cclC-cathoJe tubes. Gives 

traffic tlow security. Size = One 6 f~ct x 19 inch 

rack per twin ch..~nnel auplex terminal. 

B. Net~rk O¢er~ticn 

(i) If the re~uirement arises !!!2!'• the only equipment which 

cJula meet it is:-

(a.) AFSi,M ~ A non-synchr)ncus ~ermutin3 m~chine using nine 3 point r tors and 5/32 c:nversi~n l..>r 5 unit 

c:>.::e :::.i)erati~n. A liBht we1. ht t ..>r\1rrcl 9reC'. equi;ment, Size = 16 x 12 x 6 inches, .,.,ei13ht 27 .l:'ounJs exclusive 

cf taletv~e ancillary equipment. 

(11) The following aCCiti~nal equi~ment shoul~ also be c~nsidereJ 

but w~ll n~t be available f~r r.t le~st three veers:-

(a) ROLLICK MK II A non-synchronous device using subtr~ctor cy~her key derived from an electronic key 

genurator using multi-cold-cathode tubes. Si~o = will 

not exceed one 4 foot 6 inch by 19 inch reek. 

(N;jte: ROLLICK Mk I is crr:t>tographically unsllitable 

tor network operation). 

c. B2ecial &Ul'Aoses 

If a combined c ommunicPtion requirement arises o.t any time 

the following equi~ments, in n44ition to th~ae listed ab~ve, 

might be availf'ble ana sh:ula be consi,;ered :-

(1) 

(ii) 

(iii) 

(iv) 

AFSJJrf ~g• A non-synchronous uevice Using subtrrct:r 

key der vea frcm one time 5 unit tape. Consists ~f r 

basket contninine: a 5 unit topc r~rcer tn be inserted 

into the .AFS.uM 9. Sise o.na \reight of totc-l equipment 

s.e f~l' AFBhM 9. 

,,~FSA..M w...• A n~n-synch!'onoua equi:pment which transmits 

"on ilne" E'nC receives "off lino". Tape c~el'Elteu ~nlv. 

H~s tvo sensing hePCs, one for the message tape ~nc 

one f.ol' the one-time key tage, .h:&?pr:ixima.te i.1eight 

15 ~ounce. Size = 0.5 cubic feet. 

AFtftK 45• A non-synchron us equipment designea f~r use 

wi ~ ~rinter or te~e transMitter givinB sequential 5 unit si&n~ls. Hns one eenainc hea~ (for c~time 

key tape) anc selbct~r m~ch3niem, Appr~ximate weight 20 pounas. Size = 0.5 cubic feet. 

ROLLICK MK. I A non-synchronous ~evice using subtl'actor 

cypher key aerive~ from an electr~nic key ganernt~r using multi-col~-cethoae tubes, Size = one 4 feet 6 inch x 

19 inch rnck. Nuw in ~roaucticn. ' 

(v) ROCl\EX A non-synchronous Cevice usina aubtroctGr koy dorivea frcm one-time 5 unit tepe. ?rcviJes an ell-letter 

a These equipments will intel'Work. /crvpt. 

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crypt. Transmits "on-line" and receivf)a "oft-line". 

Hae two sensing heads, one tor the message tape and 

•ne tor the key tape. Size = (including its own 

table) 20 inches x 22 inches x 38 inches (high); total weight about 200 lbs; exclusive of ancillary equipment. Now in production. 

4. The Working party further recommended that all projected equipments and detailed information about them should be exchanged 

at the first opportunity so tbnt the U.K. an.Cl the u.s. could carry 

out operational and security evaluations. 

10th JUJ.r, 1951. 

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!£8/12/i Approved COPY NO: 1,3. 

I 

. UK/us Communications Seclll'ity Conference 1251. 

Off-Line Crpher Machines. 

Report of Nork1ng Party;2 , 

as approvou-'bv the Executive Committee. 

-' ' 

• 

1. The Working Party devoted a full uay to a review or btf'-l1ne 

cypher ma.chines which are in various stnses of research, development 

and production but which are not in current use. 

2. The following machines came under review, those marked with 

an asterisk being demonstrated:-

1~ PORTEX {D.U.F.1) 

2~ SINGLET 

3 • . PEBDRAGON 

4f Permuting 

11.209 

5. Electronic 

Cypher machine 

96· do. 

7!- ROCKEX: Security mod.1tications 

u.a. 

- 8~ AF8AM 7 

9. AFBAM 36 (M •• c.11.) 

10. AFSAM 47 {P.C.M.) 

11~ DEM 17 

Relevant Papers 

Description 

Security assessment 

Seclll'ity assessment 

DescriDtion of 

bigramming device 

Description 

Security"assessment 

Desc1•iption 

Description 

Description 

Description and security 

assessment 

Description an.ii. security 

assessment 

Security assessment 

Description and secUl'ity 

assessment 

Description and security 

assessment 

Description and security 

assessment 

Description 

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BRUBA C/S 

.508 

509 

12 

512 

.504 

513 

515 

516 

517 

1 

13 

5.36 

3 

15 

16 

18 

/12~ 
12~ DEM 21 

13. Alphabet 

Generator 

machine 

Others 

14. M.209: French 

moClifications 

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Description and security 

assessment 

Description.. 

Description a.nd security 

assessment 

BRUSA C/B 

19 

518 

3. The Uorking rarty wish to record that there was the most 

free discussion of all aspects of these 1J1ach.J.nes, that the 

resultant interchange of views was of great value to the 

representatives of both countries and that no important points of 

disagreement came to light. 

4. The 1iorking :&.arty further .mcommendea that all projected equipments ana detailed informntion about them shou1c be exchanged 

at the first opportunity so that the U.K. and the u.s. could 

carry out operational and security evaluations. 

-- 9th July, 1951. 

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WS/!3/.R. Apprgyed. Cony No: 13 

u.K./U.s. OCJOOJNICilIONS SBCURITY CONFBBllNCB 1951. 

Replacement of tbe c.c.K. 'by BRU'l'US and Improvements to the Existing c.c.x. 

Report of WorkiM Party 3 

as approved 'by the Executive Ccmnittee. 

A. Replacement of the c.c.K. 'by BRUTUS. 

1 • The BRUTUS HAZE. 

Tbe 'iorldng Party considered tbel security of the maze f'or the BRUTUS 

or,yptographio system and ma.as the follow:lng reocmnendations:-

(a) that the ROTOR MOVBllENT should be suoh that the rotors in positions 

two and six should step in opposite directions to the rest ot the 

rotors: these latter step :l.n the direction of the present COM (AJAX); . (b} tbat the ROTOR STEPPING ORDER slx>uld be as follows:• 

(1 Rotor 4- steps with each encypher.nent. 

(ii Rotor 6 steps it rotor 4- is in a :notched position. 

(iii Rotor 2 steps if' bath rotors 4- and 6 are in notched positions. 

(iv Rotor 7 steps U rotor 2 is in a notched position. 

(v Rotor 1 steps if rotor 7 :ls in a notched position. 

(vi Rotor 5 steps if rotor 1 is in a :notched position. 

(vii Rotor 3 steps if rotor 5 :ls in ·a :notched position. 

(c) tbat RliKOV.ABii!l C.AK C<Jf.COURS aa reoamended by the 19.50 U.K./U.s. 

Cammmications Seour1t;r Conference for use with the ex:Lsting c.c.x. 

should be adopted fqr BRUTUS and that the U.K. and the U.S. 

teolmicians sbould emhange technical ilitomation and prototypes in 

order that the most suitable design sbould be adopted for ccmnon use 

by all Services. As, dur:lng operation, OZlJ3 one side of a rotor is 

used to etteot t:he stepping motion eaoh set of rotors sboul.d be 

provided WJ.th a set of removable cam contours nth identi t;r numbers 

but with no alphabet and a set of alphabet rings without contours. 

In use, therefore, eaoh rotor would be titted with one rmovable oam 

contour and one alplabet r1ng; 

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that the number of notches in the NOlCH PmERN on azq removable 

cam contour should not be other than 7, 9, 11, 15, 17 or 19. 

The questions ot conseautive :notoh pa.tterna, the possible provision 

of special high incidence notoh cam contours f'or the centre rotor 

and tho reversibility of the notch r:lng sboul.d be the subject of' 

turther stud1' and an e:xchange ot views between the u.s. and U.K. 

or,yptograpbic security agencies; 

that a SE'.1' OP ROTORS should consist ot ten :rotors i 

that the wm.ING of each rotor in a set sh>uld be d:ltterent and 

tba.t the wirlng of each :lDiividuo.l rotor should contain 18 

distinct intervals (1.e. clittertm"t v:!re lengths), the rmli1ning 

intervals falJ:!ng where t'bay ~· 

In oonsideJ"ing the rotors f'o:r the BRlJ'l'US cr.rptos:vatem tm \fo:dcing Parfi7 took 

note of tm f'aat that tor the C.C.K. the U.K. and tbe u.s. Services were 

00111Ditted to rotors of different sizes am reca:mnended that there should be no 

a'fltempc at standardisation f'or ezist:lng equipnents. 

2. Otbar BRUTUS Security Factors. 

The Wo:ricing Party 0011Sidered the other security faatora relative to tbs 

BR1lTUS ceyp1iographio system. 

(a) Cailpilation of Kq Lista, 

(1) Tbe Worki!Jg Party took note of a u.s. proposal to produce 

an equ1pnent to speed up canpilat:l.on of keJ' lists and 

recanmended that the U.K. cr,vptographlc &geDCJ' be proviclad 

wi'tb details as they beoane available. 

(ii) Tbe llorlcmg Party took note ot the U,K. metbod of printing 

key lists v:l.th tm first day of the period at the bottan ot 

the sheet to :faoUitate earl,y .destruction o:f obsolete keys in 

hazardous areas and reca:mended tlat the application of this 

metbod to BRUTUS key lists should be e:mmined. 

(b) Indicator and Operatine; Procedures. 

The \forking Party took :note that the prJme user requiremen't was for 

the 1timpleat procedure oanpatible with securi-cy. Subject to th:La 

general observation 'the Working Party recommended -che.t the ' 

Incb.co.tor Procedure am the Operating Procedure f'or the BRt7.rUS 

cryptoayste.1J1 should be i:he subject of turther stuiq and an exchange 

ot dews between i;he U.K. and tha U,S. cr,yptographic security agencies, 

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,3. Restriction OD the Operational Use of' mmruB. 

The \lo:ridng Party reaanme:nded that there sbaul.d be no reatriot:l.on on the 

level at wbiah the BRUTUS oryptosystem could be used but that :ln aocordanae with 

the agreement between the U.S. and the U.K. Chiefs ot Staff disclosure of the 

BRO'l:OS cr,yptoaystem should be confmed to the appropriate authorities in the 

U.S.A., U.K., CBlJ8.da., .A.ustra]ja and New Zealand. 

4-. ReguiremeDt for Teleprinter PacUities 1n mao'hmea embocly:IJ!a BRUTCJS. 

(a) Tbs 'foziting Party considered the following draft reoarnendation made 'bJ' 

:representatives of ,;he B.J.c.E.B. and the u.s. J.c • ...E.c. at their 

~oint meeting mld in London :in June 1951 :-

"The B.J.C.E.B. and the u.s. J.C.-tB.c. after ccmsidera.ble 

d1aausa:l.on agreed tba.t it was desirable for Canb:lned otf'-1:1.ne cYriJer 

equipnents, which would be desigmd :ln the future, to ba?Jdle the tull 

raJJge of' the Canbmed teleprinter alphabet and to operate :tran a 

stanaard teleprinter keyboard". ' 

(b) The Wcmd.ns Party noted that the B.J.c.E.B. and the u.s. J.c.-E.c. were, 

o.t the t:lme, discussing onq oft-line equipnems. Had on-line equipnents 

been under disau.ssion the same reccmnendations would, no doubt, have been 

m.de. 

(c) After considerable discussion the ,1orldng Party conohl.ded that tbs 

present variation 1n designs of the keyboard on ezist:lng u.K. and u.s. 

ott-l:lne oypber equipnents arose frm. a. tn?JJ3amental di:f'f erence 1n message 

writ:lng procedure adopted by the respective Service Staffs. Until this 

difference in staff practice 118.8 resolved it would be mremeq dittiault 

to resolve the aryptograph:f.c problan. Bearing in mind that the new series 

of A.C.P.'s might help to resolve the staff differences, tha Working Party 

recanmenaed that the provision of full teleprinter keyboard facilities on 

future of'f-l:lne cypher ma.chines should be the subject ot further stwV" 

and eza~e ot views and that this sub~eot aboul.d be raised agam at the 

next U.K./U.S. Camm1nicationa Security Conterenae. 

B. Tbs Exht;lng c.c.M. 

5. Improvements to the E:z:iating c.o.K. 

(a.) The '1o:lid.ng Party reviewed the steps taken to :Improve the aeourity of the 

ezistins c.c.:u:. in accorclanoe with the recommendations ot the 

1950 U.K./u.S. Cammunications Security Conference o.nd noted:-

(i) tbat additional rotors to :l.norease the size of' all sets used for 

u.K./U.s. traffic fran 10 to 20 rotors per set were in course at 

production and that all u.K./u.s. c.c.x. cryptosystema shauld be 

based on sets at 20 rotors by 1st Jam.aey, 1953; 

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(11) that the U .K. and tbe U .s. lad solved tm problem of fittiJJg 

removable oam contours to their respective rotors but no mahmge oi' 

suoh rotors tor trials had yet taken pl.ace. As soon as this emhange 

sba.11 have taken pl.aoe mJd the i':lml design had been agreed, production 

will be initiated and the system introduced aa soon as possiblt'; " 

(iii) t})a.t a new aisguised :indicator procedure bad been wo:dced out by 

the u.K. and u.s. c:eyptogra:phio security agencies a:nd. this procedure was 

awaiting rat:lf'ication by the u.:i.-u.s. J.c • ..E.Ca.wi.th a view to its 

:lntroduction on a Canbhled basis as soon as possible; 

(b) The florkiZlg Party considered the operating procedures for c.c.M. at 

present 1n i'oroe and recaamended:-

(i) that VARIABIE SPACJNG should be applied to all messages. 

Tm slight difference between exist:lng U .K. and U .s. procedure has 

been reccmoiled and steps will be taken to :lnt~e the agreed 

procedure aa soon as possible; 

• (ii) the BISIETIQN PROOEDURB should be applied to all mesaages a:nd in 

long messages should be applied once in each cr,yptographio part; 

. (iii) tha.t Sll>RT MESSAGES sbould :aot be padded; 

(iv) tbat the use at SDIPLBI SBTTlliGS sbaul.d be considered with the 

present c.c.11. (AJAX) whenever overall l.ong-te:m security is required 

at the higher levels irrespeotive of whether the other security 

refinements recaimended bad been introduced and, with this e:nil in view, 

tmt a stuay sboul.d be ma.de of the problems involved in the ocmpilation, 

prcduct:lon a:nd operational use of Bm:plex Settings with the c.c.:M.; 

(v) tbat c.c.x. PROCEDURE for use on NATO oryptoneta should be the 

same aa on. canb:lned mts. 

11th July. 1951. 

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LQS/«4/R Approved COPY NO: 13 

tJK/US Coamunications SecUl'ity Conference 1951. 

Combat and Low Echelon cryptosystems (including Authentication). 

Report of Working ~arty 4 

as approved by the Executive Committee. 

1. The Working ~arty took as the basis of their deliberations 

.Annez 'P' of the paper C/BC 55, dated 21st June1 1951, prepared by the ux,/us JC-Ecs. 

2. 

e 

Combat Brstems 

(a) Navy 

IT "NAB AGREED thflt since the UK/US JC-ECs. hnd not 

reached agreement as to whether a combined major war 

,vessels tactical cryptosystem was required, no 

progress on this item could be mad~. 

(b) Army 

(1) Air Support Control Codes. 

A. IT \'/AS iaGREED: -

1. that the requirement under this item voula 

eventua.lly be met by the provision of.suitable 

ciphony equipment; 

2. that pendinc the provision of such equipment it 

woula be necessary to use special purpose codes. 

B. IT WAS NOTED:-

that the British Azm:y were considering the use of 

a short vocabul."'19y coue recypherea by one time 

pau (ASREX) for this pl.i.l'~ose. 

C. IT \7AB RBCOMDNDED :-

that ASREX should be studied with a view to 

possiblo combined use. 

(i1) Map Reference Codes. 

A. IT WAS .AGREED:-

1. that the requirement under this item would 

eventually be met by the provision of suitable 

ciphony equipment; 

2. that pencling the provision of such equipment it would be necessary to use special purpose codes. 

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B. IT ~-/AS NOTED: -

1. that the u.s. Army reliea en locally produced 

coaes tor this purpose. 

2. that the British n.rmy used UNICODE but that 

the socurity or the system was low. 

3. thnt the Dritish Army was considering the 

following systems tor this purpose:-

JIAPFRAX 

Double MAPLA.Y 

C. IT \iAB RECOMMENDED:-

thfl t MAPFRAX and Double KAPLAY should be 

studied with a view to possible Combined use. 

(iii) Status Reporting Codes 

Forward Echelon Voice Codes 

A. IT \u"S NOTED: -

that the UIC/UB JC-ECs. considered that there 

was no requirement for Combined agreement on 

these systems. 

(c) Air Force (Ground-Ground) 

(i) Aircraft Movem~nta Code 

A. IT WAS AGREED:-

thnt the requirement unaer this item might be 

met by the provision of a suitable light weight oft-line mach!ne crypto-srstem. 

D. IT 17AS NOTED: -

that a special purpose code tor this purpose 

was currently under Jiscussiun by the UKlUB JC-ECs. 

(ii) Friendlr Aircraft Approach Code 

Ground Radar Reporting Coues 

A. IT i/AS NOTED:-

(d) Air-Ground 

that the UK/US JC-Bes. considered that there 

was nu requiremant for Combined agreement on 

these systems. 

(~) Maritime and U-boat ~arfnre 

Bomber and Supplr/Tru~p Dropping O~erations 

A. IT WAS AGREED:-

1. that the requirement unaur this item might be met 

by the provision ot a suitable light weight off-line 

machine cryptoaratem. 

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2. that pending the provision of such a system it would be necessary to use vocabulary codes 

for this purpose. 

B. IT Widi NOTBD: -

that the provision of such vocabulary codes 

was currently under discussion by the 

UK/US JC-ECs. 

(11) Meteorological 

A. IT ~iAS AGREED:-

that c ons1deration of this item should be 

referred to Working Party No. 6. 

(e) Am.phib;J,ous Operations 

A. IT ~AS AGREED:-

1. that the requirement under this item might be met by the provision of a suitable light weight off-line machine crypto-system. 

2. that pending the provision of such a system it would be n&ceseary to use a vocabulary code 

for this purpose. 

D. IT ~.AS NOTED:-

that ·tho UK,/UB JC-.ECs. had recently agreed that such a Combined code should be provided and that AFSA and GCHQ were currently engaged 1n 

its compilation and production. 

(f) Authent1cntion 

A. IT .lAS NOTED: -

1. that authentication publications were currently 

unuer discussion by the UK/US JC-Ecs. 

2. that i\FSA had under development two 

authentication aevices for challenge and reply 

use on limited communication nets:-

= ~ ~~ : ~~ B. IT ;lAS RECOMMENDED:-

that further consideration shoula be given to 

ASAD 2" (x - 1) ancl ABAD 2 (x - 2) with a view 

to their possible adoption for Combined use. 

/Low Echelon 

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Low Echelon and Combat Systems in General 

3. The three main Combined low echelon and combat requirements 

stated by the J.c.-E.c. are:-

(a) Naval low echolon communications 

(b) Air-Ground Commur1ications 

(c} Amphibious Co11111unications 

' 

4. The ~orking Pa~ty considered the hand crrptosystems which 

will be available within the iomediatc tuture. It was agreed that 

the following will be available:-

Strip 

LmEX 

PLA.YFEX 

Vocabulary Codes 

5. The Working party also considered the ma.chine systems likely to be available tor intermediate and long term solution 

ot the requiremsnts in paragraph 3 3bove. These machine 

systems o.re:-

U.K. 

-

PORTEX 

u.s. 

-

11.C.M. 

Al'BAM 7 

AFSAll 47 

DEM 17 

It was noted that:-

(a) delivery ct the first 50 models of PORTEX tor field trials 

was about to begin. The uo.te on which quantity production could begin uepancled on the lensth and outcome ot field 

trials but tools existed for the me.~ufncture ot a limited 

number of mo.chines should they be r~quired in emergency prior to the completion of field trials. BJ the end of 

1953 production could be built up to 100 machines a week; 

(b) arransements tor the production ot MCM were well in hand. 

Providing the equipment proved satisfactory delivery would 

start Within a rear and it was expected that 2,000 machines 

would be available within two years. Thereafter there would 

be a production potential ot 30-40,000 mechines a year; 

(c) although service test trials were not vet complete, tooling 

tor production of AFBAM 7 had begun. It was expected that 

by 1952 the production capacity would be 5,000 machines a 

year; 

(d) arrangements for the production ot AFBAM 47 would follow. 

No dates or production capacity could yet be definitely stated, but a production rate ot 500 a month could be 

attained by 1953; 

/(e) 

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(e) a first model ot Diii 17 was demonstrated to the 

Working Party and deTelopment ot an improved model 

was being pul'sued as rapidly aa possible. 

6. For security reasons, an.a in the light of present cryptographic techniques, it was agreed t'hat, wherever operational circumatancea permitted, more thon one crJptosystem should be 

used for Combined literal cypter purposes. 

7. Naval Low Echelon Coamunications. 

(a) ShOl't tel'Dl solution. 

It waa agreed that only hand systems are available 

for limited Combined naval uae, ana that the choice lies between 

the following two systems:-

Strip 

PLAYRX 

It is recommended that as scan as possible U.K. ana u.a. should 

carry out operational and security evaluations of the above systems respectively, W1 th a view to reaching agreement on which /system 

shoulCI be used. 

(b) Intermediate and lone: term solutions. 

It was agreed that limited Combined zaaval communications 

should be treated as an exception to the principle recommended in 

paragraph 6 above and that the Brutus cryptosystem should be used 

both for low echelon and high echelon communications. It was noted 

that after trials of ~All 7 and AFBAll 47 the u.a.N. are likely 

to adopt one of those equipments for int~a-Naval use. The riorkins 

Party therefore recommended tbat as a matter ot urgency, the U.X. 

should develop a parallel me.chine employing the BRUTUS technique. 

ti 8. Air-Ground Comuni cations. 

Certain aspe~ts of air-ground communications have already been 

covered in paragraph 2(d) above. The ~orking Party considered that 

the requirement for combined cryptosystems tor air-ground corrmunicationa requires clarification. Where a machine requirement exists, it could probably be met br one of the equipments described in 

paragraph 5 above. 

g. .Amphibious Communications. 

(a) §hart term solution. 

Thia is covered 1n parosraph 2(e) n above. 

(b) Intermeaiate and long term solution 

It was agreed : -

(i) that there ia probablr a requiremtJnt for a mechanically operated off-line cypher machine and for an electrically operated analogue ot such machine. 

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{ii) that the M.209 principle appeared leassuitable 

than a permuting maze from the security angle, 

and also owing to the difficulty of providing sufficiently speedy operation 1n an electrical 

analogue. 

(iii) that it is not yet possible to make detailed 

recommenaatiuns on what machine should be used. 

10. Bxchenie of Eg,uipments. 

' It was recommended that ell projected equipments and detailed 

information about them shoula be exchansed at the first 

opportunity so that the u.K. and u.a. could carry out operational 

and security evaluations. 

26th J'uly. 1951. 

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LC8Jll5/R Approved CoPY NO: 1, 

UK/US Communications Security Conference 1951. 

Merchant Shipe' Cryptoaystems. 

Report of Working rarty 5 

as approved by the Executive Committee. 

1. The Working rarty took as the basis of their deliberations 

Annex 'C' of the paper C/SC 55, Gatod 21st JUne, 1951, prepared by the UK/US JC-ECs. 

-he &resent Situation. 

2. Tho ~ork1ng Party reviewed the present e111llat1on. 

IT \"'iAS NOTED: -

(a) 

(b) 

that a quantity of merchant ship crypto-material le~t over from ~orld ~ar II wne available for 

issue in the event of war in the immediate future. 

,that arrangements tor the production of the Merchant 

Ship Cipher De7ice (AC? 212) ana aseociateJ .key material, which would replace world War II systems, had been agreed between AFBA and GCHQ. ?reduction 

would begin iIPIDediately. The Device and 

associated ker material should be available tor issue 

in the Spring of 1952. 

~!placement cf the Merchant Ship Cipher Ddvice (~r 212) by a Machine. 

3. IT \iAS AGREED that the following proposed amendme~ts to 

Annex 'C' of the paper C/SC 55 should be forwarded to the UK/US 

JC-Bes. for consideration:-

(a) Amend paragraph 1. to rend:-

"1. Combined communications are required. It is essential that Ca.nnu1an., u.K., u.s. anu 

all1ad naval authorities and -;mrships should be 

able to communicate with any Canadian, U.K., u.s. 

or allied merchant £.hip and with any neutral 

merchant ship trading in the allioa interest." 

(b) Amend paragraph 7 to read:-

"7• C~her Machine - Drive. 14c:i.nual or power drive <;f11 be acceptable. It manu~l drive is provi~ed a power ariven cryptogrnphic analogue shoul::l nlso be provided." 

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4. The Working Party reviewed the machine crypto-systema available and pro~ected. These were:-

PORTEX 

MC.II 

AFBAM 7 

AFSAM 47 

DEM 17 

Permuting M.209 

French 11. 209 

.nnY na\7 mnchinc \7b1ch m. ''I be., .... c.vc1ope..: tor low uChl.lon 

use. 

IT WAS .AGRDD: -

(a) 

(b) 

(c) 

(d) 

that in selecting a auitable cypher mrchine for 

merchant ship canmunicetions it uc.s noceesary to 

pay particular attention to the aspects ot cost 

and simplicity. 

that for these reasol16 provision of n merchant ship cypher machine was n separate problem not necessarily related to the problem of proviains a low echelon 

cn>her mechine for Service use. However it would 

obviously be a great advantage if the same basic 

machine could serve both purposes. 

that it was not ~ossible at this stage to recommend 

a particular IL~ch1ne for merchant ship use since 

further aevelopment and experience of the various 

machines listed above was first required. 

that failure to recommend a particula.r ma.chino at 

this time would in no war delay solution to the 

problem since development of nll possible ms.chi~es 

was progressing at n rate as rapia as available 

funds permitted. 

13th July. 1951. ' 

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Oouy No: 13 

!!/US Camnunic~ons Security Conference, 1951. 

lle"Ceorological Czphers other than Oif'ax. 

Report of' Working Party 6 

as approved by the Executive Caumittee 

1. The Workmg Party took a.a tbe basis of' their deliberations Amlex 1G1 of the 

paper C/SC 55, aa.ted 21st June, 1951 , prepared by the UK/US JC-:ms. 

2. IT WAS AGREED that the following proposed amendment to A.JJDex 1G1 of the 

pa.per c/sc 55 sboul.d be forwarded to the UK/OB JC-EOs. tor oonsidera.tion:-

(a) Amend pa.ra.graph 2(c) to read:-

"(c) M'anual (preterabq one-time)". 

Bnm:lnation of' tbs Canbined Opera.tioml Regu.irements, 

On-line Eguipnent 

3.. The Working Party reviewed the on-Um cr,ypto-systems available and 

projected. These were:- ,. 

Apparatus AFSAM15 5 U.O.O. No. 1 l 

Circuit MERCURY Symbromus 

.ARTICHOKE 

AFSAK 2 - 1 I AFSAK 9 

ROLLICK ~ llC>ll - SJmhroaaua 

Couventional. one t:lme tape systems 

IT WAS AGBDD:-

(a) tbat it ns not possible at this t:ime to select B.IJ1' partiaular 

equipnent for Canbined use. Selection tran tbe above systems could 

best be made when the requirement for ou-line equipnent arose 8l1d 

depending on ciroumstances rulllig at the t:ime. 

Off-.11ne Eguipnent. 

lt-. (a.) General Diaseadlia.tion of' Weatber Infoimation. .. 

A, IT WAS .A.GBEBD:-

1-. tbat for ~ use the present COM modified for weather 

encyphe:nnent (tmt is using a weather switoh such aa .AFSAll 100) 

could be used f'or this p.1rp0se as soon aa the necesaar.r 

moditioa.t:l.on kits, speo:l.al rotors and key lists could be made 

available; 

2. that wben the BRUTUS systEm replaoed tm present COY for 'Ul/DS 

use it too could be used tor weather emyphsxment provided 

special rotors and key lists were used. 

/(b) 

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(b) \'feather Rei>ort;lng Posts and Ket. Reoozmaissance Flights. 

A. IT W.AS NOTED:-

1. tba.t in the :imr.lediate future the UK Services intended to use 

one tme pads; 

2. that AFSA lad under develop;:i.ent a digital fom of the DIM 21 

(K.209 modified for one time tape operation) and that this 

equipnent might prove suitable for the transmission of reports tran 

posts and aircraft to oolleoting centres; 

3. that the U.K. had under consideration a modi:f'ioation to PORTD: to 

make it suitable for the eneypmxment of met. data. 

B. IT WAS AGRBD:-

1. that the one t:bne pad was the onq system in:mediateq available; 

2. that furf;her oonsideration should be given to a digital foim of the 

DEM 21 and PORTEX with a view to their possible adoption for this 

purpose. 

(c) J .. ir-Ground. 

A. IT WAS NCYrBD:-

1. that .for the transmission of weather_ :lzlf'oxma.tion to aircraft :in 

flight the Ro,al .Air Force used the UCO system; 

2. that Al!"SA lad under developnent two devices for this PJrPOSe:-

ASAD 1 (.I - 2) 

ASAD 1 (X - 3) 

B. IT WAS AGREED:• 

1. that UCO was tbB only system hmediately avail.able, and should be 

oons:ide:r:ed for Oanbmed use. It was used sucoesstul.l,y during World 

War II by both tho Royal and u.s. Air Forces; 

2. that further consideration sh>uld be given to ASAD 1 (X-2) and 

ASAD 1 (li-3) with a view to their possible adoption for Oa:ib:lned use; 

3. that turtber developnent of ASAD 1 (X-3) was highly desirable in 8:rf3 

case since it was also likely to be valuable :tn other fields, e.g. 

"Statu!!" Reporting Codes; 

4. that tor the transmission of landing weather int01mB.tion ciphor\J 

equipnent :Ls reoanm.ended as the long teim solution .. 

I 

Tm Jmplications of NATO cm the Foregoing Requirements. 

On-line Egu:Lpneut. 

5. IT WllS AGBIED:-

that shruld it be deoiclSd to issue on-line equipnent to NATO powers, 

conventional one-t:une tape systems were to be preferred. The use of 

these would protect UK/DB o:eyptographio techniques and the equipmmt 

ns the mast likely to be available. 

/6. 

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Ott-l.:lne Eguipmmt, 

6. (a) General D1ssmnil1ation ot Weather Inf'ozmation, 

J ... , IT WAS AGREBD:-

1. tbat to proteat tlK/lJB ar,yptogra.phic teclmiques the ~ system 

whioh oould be oonsidered for this ~sa was tbs present 

CCK modified tor weather enaypbexment ( tmt :ls ua:l.ng a weather 

switch such as JtFSAK 100) ; 

2, that ow:il:Jg to tm small number of CCII machines available it as 

unllke]J that this equipne:nt oould be provided in sutticient 

quantity for NATO met, purposes for at least two years; 

3, that no other system as available and therefore in tbe int~ 

period it would be necessar.Y for each IW!O power to use its awn 

national met, systems with ad hoc arrangements for tb= 

dissemilJB.tion of :lnf'ozmation to other powers, 

(b) Weather Reporting Posts and Ket, Reconnaissance Flights, 

A, IT WAS AGRE!D:-

that provision of suitable systems for these purposes should be 

the :i.ncb.viallal. responsibility of eaoh NATO power, 

(o) .Air-Ground. 

A, IT WAS AGREED: -

1, that it vas highly desirable that a cammi system be held b.r all 

N.r\.TO powers tor the transmission of waatmr :information to 

a.imro.ft in flight; 

2, tmt UOO was the ~ UK or US system :b:mediate]J available for 

this purpose, 

Exohme;e of Bguipgent, 

7, IT WAS RlEOMMBNDED that all projected equipnents and detailed into:matian. 

about them should be exchanged at tbe first opportlmity so that tbe U,K, am the 

U,S, oould carr,y out operat:l.onal and security evaluations, ... 

2oth JuJ.t, 1951. 

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COPY NO: 13 

LCS/W?/R Approved 

UK/US Communications Security Coni'erence, 1951 

CI FAX 

Report by Working Party 7 

as approved by the Executive Committee. 

1. The· Working Party discussed the following equipments :-

U. K. U.S. 

METF.AX AN/UXC 2 

A.SAX 3 

2. The Working Party took note of Annex 'D' of the paper c/sc 55, dated 

21st June, 1951, prepared by the UK/US JC-ECs. They considered that joint 

operational requiremer.t3 were at present too undecided for any combined 

agreement to be reached. 

3. The Working Party agreed that, should a requirement arise during the 

next two years for an equipm6nt for combined use, selection could only be 

m~de frpm the following equipments which might be available in limited 

quantity : 

AFSAY 806 (referred to in Report of Wo~king Party 8) 

AN/UXC 2 

METF.Ax: 

Ji., It was recorr.;nended that all projected equipments and dete.iled information about them should be exchanged at the first opportunity so that the 

U,K, and the U.S. could carry out operational and security evaluations, 

26th July, 1951. 

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LQ&/18/.R Approved copy HQ; 13 

UJ/US Comm:unications Securitr Conference 1951. 

CIPBONY 

Report of Working Party 8 

as approved by the Executive Committee. 

1. The Working Party reviewed the following u.K. and u.s. 

C1phonv equipments and projects:-

BANGLE 

HALLMARK I 

HALI.Mame II 

PICKWICK 

D.70 

WHISPlm 

SORCERER 

TRUMPETER 

u.s. 

-

AFSAY 806 

ASAY 8 

ASAY 4 

ASAY 5 

AN/TRC 25-ABAY 7 

v'ocoder basic research 

2. The Working Party had detailed technical diacuasio11s on all 

the items listed above, including demonstrations where practicable. I 

3. The Working Party took note of Amlex 'E' of the paper C/BC 55, 

dated 21st .June, 1951, prepared by the UK/UB JC-ECs. but concluded 

that, for the present, no recorrmendations could be me.de about the 

selection of equipment to meet co~bined requirements as now 

stated. 

4. The Working Party took note:-

(a) 

{b) 

{c) 

that the u.s. Air Force considered that secure 

air/ground end air/air communications ware matters 

of the highest priority, and had therefore defined 

to A.F.S.A. the military characteristics of a 

ciphonv system which A.F.s.A. was already coamitted 

to develop. 

that exiatins u.s. u.H.F. and v.H.F. air/ground and 

air/air radio sets could be used to transmit and 

receive c1phony of the general type requiring binary transmission at a rate of about 24,000 bauas per second with virtually no modification to the sets 

concerned. 

that th~ ciph~ny equipment AFSA.Y 806 could encJpher black/white facsimile or 3 channel tele~ype as 

alternatives to speech. Furthermore that Bangle coUld be adapted to encypher half tone facsimile 

pictures. 

/5. 

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5. The Working Party sussestea that the u.K. and u.s. services, in formulating their ciphony requirements, might find it helpful 

to make operational trials of pulse code moJeulation as a 

commwiication technique without security equipment. The 

attachment of a security aevice to the p.c.u. equipment would not 

alter the communications characteristics ot the latter. These 

trials would enable the Services to assess the inherent operational complications ariaina from the use ot encyphered speech. 

6. The Working Party concluded that no tactical cipbony sratem 

in the 2-30 mes. frequency range suitable for either shipborne 

or vehicular use would be available in the neBl' tuture. 

7. The Workins Pnrtv recoDmended that all projected ciphoDJ equipments and detailed information about them should be 

exchanged at the t1rst opportunity so that U.K. and u.s. could 

corrr out operational and security evaluations. 

25th Julr, 1951. 

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IQB/ly9/R Approved con 10; 13 

me/Us qonmunications Security Conference 1951. 

CYPHEB KEY GENERATION. 

Beport of Working fartr g. 

as approved by the Executive Conmittee. 

1. The norlting Partr reviewea the following equipments and 

projects for the generation, proauction ana checking of cypher key:-

TRIMMER · ROCKEX by Generating Equipment 5 u.c.o. Ker Generating Bqulpment Ker Tape Checker 

lWlL 

ASAP 44 (high speed recorder) AFBAL 5116 

one t1me Key Generator 

f.or AFBAY 806 

2. The Working Party took note that there was no combined 

operational requirement for key tape generating equipment. The 

5 unit Ker tapes usea by both the u.K. and the u.s. are intercha:aseable and the equipment of either nation could therefore be 

used accor.Q.1ng to circumstances. It was agreed that the combinea 

standard of ranaomnesa detailed in Appenaiz A should be eocepted 

and that the situation should be re~iewed at all future conferences 

aa a regular item of the ogenda. 

3. The Workins Party reconmended the tollowins exchange of 

information:-

~ (a) The u.s. to supplr:-

(i} Outline description together with pbotographs of AP8AF 44. 

(ii) A model of the 900 operations per minute perforator. 

(11i) The manutacturing specification for paper tapes together with samples of the 5-unit and 7-unit sizes, including the description of the ageing teat with experience of 

wear on machines. 

(iv) Further information on how the number of breaks bad been 

limited in the recentlr supplied ROCKEX tapes. 

(b} The u.K. to supply:- ... (i) Full details of the high speed Checker. 

(11) Details or "The Timms Counter". 

(Ui} A model ct the 100 unit pel'forator (three beaded punch). 

26th Julr. 1951. ... 

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APPENDIX A 

Randomness in key is intenCled to prevent discrimination 

between key and the r&naom expectation in the trpe of Ker material 

generated. This is a quantitative effect and practical considerations place a limit on the randomness. 

The following limits have been agreed:-

(i) Kera showins a deviation of 2 aisma or less from 

ranaom in all counts are acceptable. 

(ii) An.r Xey showing a deviation in any count of 4 sigma 

or more from randbm expectancy is unacceptable. 

(iii) No Ker showing a deviation in anr count of between 

2 sigma and 4 sigma from random expectancy may be 

used without further examination. 

(Note that these criteria may be stated either in tel'IDs 

of SiSD1$ as above or 1n terms df the appropriate probabilities.) 

2. Counts to be made must de,a:1end on the actual method of 

generation. However, the followins counts based on stretches 

ot at least 10 1 000 consecutive wiits of Key are common to all 

methods ana will apply to all types of Ker tapes. 

(i) Frequency count ot s1nsle units of Key, 

(ii) '

11 " " consecutive pairs of uni ts of 

Ker (for binary material the mod 2 sum of 

consecutive pairs). 

(iii) Suitable multi-wiit counts to ensure correct 

operation of the generating and recording equipment (for binary material runs of 15 

consecutive delta dots and delta crosses are 

counted). 

3. For multi-level key these counts will be made tor each 

lairel independently and for the units of Key considered as one 

stream in the order of emission from the generator. 

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CORY No: I~ 

PK/US Camnmi cations Security Conf'erence 1gs1 

Secure Wrapping ot C.rpher lfa.teria1 

Report at World¥ PariT 10 

aa approved bl the BEecutiva Camd.ttee 

I 

1. The WorldlJI Party reviewad the aya1;ema at proteati!Jg 017P'togra.phio 

doaumenta demonstrated by the British members as tollowaa .. 

Pads with sealed eages 

Welded plastic envelopes 

2. !he WmclrJa Part7 took note ot Amiex I B' ot the paper a/SC s~ ~ 

dated 21st June, 1951, prepared by the Ul'/Us JC-ICs. aZJd noted that mme 

ot the projected schemes could be expeated to give proteation under 

airaumatanaes other than those in which an Agent ha4 onq limited time 

aZJ4 f'acili tiea at his disposal • 

.3. The WorldzJg Party reaammmded that samples at the qatama damonatrated should be su;pplied to the u. s. for atua.y an1. aarment. 

4. The Workina PaiV reCClllD8l'Jdecl that there should be a acmtinu:lng 

a:ahange ot ideas am. teahniques. 

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OOPf II>: Ii!, 

LCS/!1p Approved 

t¥tJs Ccmmmications Security Conference, 1951 

I.F.J'.: Security Aspects 

Report bl W'orlcing Party 11 

as approved 'bl the Executive Camdttee 

1. !rhe Working Party cliscussed in considerable de~ail the various U. lt. 

an! U.S. proposals for an I.F.F. Security System. 

2. The Work:l.!lg Party concluded that the techniques of neither nation ha.a 

yet reached a su:f'fiaientl.y advanced stage for it to be possible to reco11mend 

equipnent for Combined use but they agreed that .tuture developnent should 

take into consideration the following faotora:-

(a) That the code &)'stem ahoul.d be inviolable ta myptanalytic 

attack by cataloguing ohallenges and replies. To this e:nd 

the total possible chall~es 8Jld replies on fl.JV' one setting 

should probabJar exoeed 10 • 

(b) That an automatic zeroising system operating whenever a 

plane lands or crashes is desirable to reduoe the ri.sk ot 

~ioal canpraniae of dail.1' settings ot the coaing dev:Loe. 

J. The Working ;party reoamiended that the mr/tJS JC-'EOs be asked to state 

whether the "Personal Identity" recognition fa.aility :need be guarded b7 

cyphering or not. 

4. The World!Jg Party considered that the excbal'Jge ot vine had been most 

valuable 8Jld they turther recoume:nded that both A.~S.A. o.nd c.P.B. should 

maintain close contact with those responsible for the developnent ot new 

I.F.F. security equipment in the U.S. and U,X. respective~, so that, when 

combined equipnent eventuallar came to be considered, the equipnent developed 

in both countries would be cryptographically scnmd. 

2oth JuJ,y p 19S1 o 

.. 

TOP SECRET 

' 
·-+ ' 

REF ID:A67165 • 

TOP SECRET 

IDS/!12/R Approved. 

Cow No: 1, 

Provision of Upper Case Facilities on Off-Line. 

CYpher Ka.chines for Combined U.K./q.s. Use. 

Report of Working Party No. 12 aa approved 

'by 'the Executive Canmit'tee. 

1. The Working Party met to consider the provision of upper oas& facilities 

on Oi't'-Ll.D8 Cypter maclnnes for Canbined Use. 

(a) f'or general usage 

(b) for veather traffic 

O~ machines employing the CCM~AX) or the BRUTUS Cl"Jptographic systems 

were considered. 

2. As a be.sis for discussion 'the "1ork:i.Jlg Party accepted the following 

principles:-

(a) that 1-c was not ye-c possible to agree on the design f'or a 

Canbine<l off-line machine which wauld handle the full range of the Cm.billed 

teleprinter alpmbet and operate f'ran a standard teleprmter keyboard 

(see report of Working Party No.3 paragraph 4); 

(b) that the provision of l:lmited upper case facilities on Canbll10d 

off-l:IJ:le cypher machines was preferable to providing no upper oase facilities 

at all. 

3. The Working Party considered the keyboard layouts of teleprinters, 

teletypewriters and off-line cypher ma.chines already ll1 production or about to 

be produced (see canpi.rative 'table at-cached) and reached the following 

coZJClusions :-

(a) Provision of Upper Case Facilities for OOM: (AJAX). 

(i) General Usage. 

Except for the numerals and five pmctuation marks 'the 

upper case characters on the Typex machine are non-standard. In addi'tion, 

the T-JPB:X: uses the Z circuit for FIGURE SHlFT; U .s. maclnnes use the new 

J circuit. There is, therefore, :no possibility of providJ.rJg a general purpose 

Canbin.ed machine cryptosystem using Uppdr case characters until tbe Type:x: is 

replaced :ln the U.K. Services. 

(ii) Weather Traffic. 

The provision of upper case facilities for weather trattio in the 

Cctl(AJAX) or,yptosystem wauld require further consideration. Proposals to meet 

i;he requireMent shcul.d be emha.:nged by A.F.S.A. and C.P.B. and, if' possible, a 

decision should be reached before the next Conference. 

/(b) 

TOP SECRET 
·-+ • REF ID:A67165 • 

TOP-SECRET 

(b) Provision of Limited Upper Case Facilities on macb:lnes 

emploY1lJs the BRUTUS FiJJo1ple. 

' (1) The a:trect encryption ot ten upper oaae o!ara.aters (the 

numeral.a 0-9) can be a.ohieved by a.ck>pting the follow:lng baaio rir:lzJg~ sohme 

on AFSAK 1+7 {Pell), .APSAll 7, SJNGIET and such other u.K. or u.s. equipnents as 

may be designed tor BRt1.l'US working:• 

J: Key to be taken through the X oirauit 

z n n " n It • " .I " 

Spaoe II n n II • II z It 

y II • II II " " y " 

J II II II II II II y II 

Figures II n II II II II J II 

Letters n q II n n II Upper oase V circuit 

Lower oase V n II II II II " V oirou1t 

(11) It APBAM 1+7(PCIC) aml SINGIB!' onJ,y were to work together the 

tol.lor.lJlg additional. eight upper case oharaoters could be encrypted 

-()/:?,.. I 

(iii) In the present COM {AJAX) or.vpf;oaystem the letter Z deor.vpts 

as :z:. In th:ls somme, :ln addition, the letter J will dsor,ypt as Y. 

(iv) For u.s. machines, the :f"uJ.l scheme is incorporated in the 

present design tor .AFSAll 1+7(PCM) and the Umited (numerals micy') aoheme 1s 

:lnoorporated in the design tor AFBAM 7. 

(v) For U.K. mach:ines: 

( 1) It rill not be possible to introduce the schemes ill 

paras. 3(b)(i) a.Di 3(b) (ii) above until the U.K. Services 

cease to use Typez with a BRUTUS aaaptor. 

(2) For Canb:lned working the bigramming feature on SINGIBT/ 

PBNDRA.GON will :not be used. 

(vi) In order to l:lmit the ditterenoes between the above metlx>d tor 

seouring limited upper case taoilities and the big:remning metlx>d ot seour:lng 

f'ull teleprinter facilities th3 U.K. Services will use the tollow:lng wiring 

systElll on SINGIBT/,PBNDRA.Gm. 

FIGURES KB! to be taken through J circuit 

BIGRAM DI II II n " K n 

~Kl! n 11 11 11 y 11 

l,.. Tbe Working Party made the tolJ.or!ng recarmendationa:-

(a) that it be noted tlat until the U.K. and the U .s. Sel"V'i.oes oease to use 

tmir aurrent equ1pnents with the CCK(AJil) or BRUTUS adaptors moclit:loation to 

provide upper oase facilities otber than tor weather traff':io will be extremel,y 

clittioult • . (b) that until a Canbined Oanmunioation Policy is agreed all cypher macbines 

designed tor UK/DB uae in the :tutu.re should iJJChJ.c1s at least the l:lmiteci upper 

oase taoUit:l.es as set out m para. 3(b) (:1.) above. 

(c) tbat sboul.d tbe OOM(AJAX) be used tor weather trattia the partioular 

oryptosystem in question must ha.ndl.e weather trattio exclusively. 

20th JuJ,y. 12s1. TOP SECRET 
I U: .• i." 1.ld ' a L) •I'::;_' {.'I l' {, I.. 

e -•--~,~T ' > 

' ir:::o ... f=! ;"'\ , .. ' . 

" I ' I 

.I' r • ~ • I ..._ 

Te1 • a.nil I". .. MQc\Jndli' • ..,,..., • .. 

CCJ1rDB1"D.tive Table of U"OJJer Gase Cba.raoters. 

louer I I 

' ' Case Key A li 0 D E JP G B I J ' K L II If 0 p ~ R s T u v w x y z RElllEUks 

Teletype ~ I STOP 8 I ( ) ; 1 I 6 j The :numeral.a 0-9 

- I . 3 & 9 4 BBLL 5 7 . 2 II • • • • ' ' and-?:().,/ j 

. Wll> .-~ Teleprinter ' • R ' " @ £ 8 DELL ( ) 9 ; 1 4 I 5 7 2 I 6 ! ~ are oanmon upper - . • • = + 

u I 

oe.se o"' .. --ters 

OOMDINED 

TmJmUNmt - 3 8 ( ) • 9 ¢ 1 4' 5 7 2 I 6 J .. uthorised by ACP 126 

• ALPII/dmT 

1! . -

" ( ) ' I ,If t 

Z = figures oircu:Lt. 

.!l Typez - I v z ' x £ B • I 9 1 4 5 7 2 SP .. m 6 X = space o:l.raui.t. 

I V = letters oirouit. 

CSP 1700 -. pq No upper case. I 

Cl> - 8 ' 

J\FSl..lt 7 li i3 c D 3 F G H 8 t K L H N 9 ' 1 4 s 5 7 J 2 x 6 SP .. \.CE 

f.t f . 

i J~47 ' Current Production model I (PcH) - "I • D e ' F G H 8 J ( ) 9 ; 1 4 s 5 7 ~ 2 I 6 SP/1CE J Key used f'or f'igures • • • cirouit. 

' To give f'uJ.l. teleprmter 

SINGIET - ... : 3 % @ £ 8 BIGR/IM ( ) 9 ; 1 4 I 5 7 = 2 I 6 + facilities Z 1 B, JC 1 J 1 ll' 1 OR • I 

a.re bigrmlrled. Bigram key 

used J circuit. 

CSP 1700 

with J.PBA'M A B 0 'D 3 F G H 8 J JC L JI N 9 ; 1 l,. s 5 7 'V 2\ x 6 SPli.CB 

100 (iieathr I ;.. 

Switch) I I I : - I I 

' 

'"" ... ~~ n r --~ ' ...... """T"' 

j , f • I ~ Ii 

t~ ... , d F II • ~ ~ \.,., .... \~~ ~ '---