.. • 

USCIB: 13.5/55 

REF ID:A59621 TOP ~:LU:JLDJ 

,...r.o,..,:nr.o,.,.. • 

LW~ ~QStDmm'S S9N'3M::EN 

SQBiiWGR:e MA'l'ERiEA±. 

20 April 19 54 

MEMORANDUM FOR THE MEMBERS OF USCIB: 

Subject: Compromises of SIGJNT Information. 

1. At the request of the Director, National Security Agency, the 

enclosed memorandum from GCHQ on the above subject is forwarded for 

information. 

2. Comments by the Director, NSA, on the enclosed list of 

recommendations adopted by LSIB to improve the handling of certain UK 

crypto-systems are briefly summarized below: 

11a. We are also concerned over the danger of transmitting 

plain-text. when various on-line crypto-systems, including 5 UCO, are 

used and are investigating ways to prevent it. 

11b. We already are printing Encipher and Decipher pads, OTP, 

in different colors. 

11 c. The reconunendations regarding ROCKEX and ROLLICK are expected to result in improved security. These equipments are not being 

used by the u.s.11 

Enclosure 

Copy of DGC/4217 dtd 26 Mar 1954. 

USCIB: 13.5/55 

UFUS L. 

tain, U. s. Navy 

EXecutive Secretary, USCIB 

A-PPfliBEiB B09UMl!lN'i'S eoN'f1d'.N 

80BEiiiORB Mt:'i'EftI1tL 

Declassified and approved for release by NSA on 02-11-2014 pursuant to E .0. 1352a 

FOPSBORBf' 

24 
.DGC/4217 

26th March, 1954. 

Director, 

National Security Agency. 

-----------~-------------

COI<'.PROJ.:ISi~S OF SIGil~T INFORMA'l'ION 

As a result of the proposal, referred to in 

DGC/3555 of 16th July 195 3, tho.t L. s. I. B. should revie\V 

the whole problem of the co:npromise of Sigint information 

by misuse of Sip,int communications a nwnber of recommendation~, 

designed to bring about a diminution in the nwnber of such 

compromises, have been adopted. 

2. I am glad to be able to tell you that during the 

period 27th .July 1953 to 23rd December 1953 only three further 

compromises by U.K. authorities ha-~e been reported. 

3. I am taking the opportunity, while send.ins you, 

at Appendix, a copy of the details of these three lapses, to 

• • • enclose a copy o'f' reoo1amendations adopted by the U.K. 

concerning specific U.K. cryptosystems which are additional to 

the Rcbulations approved and adopted by L.S.I.B. which will be 

forwarded to u. s. C. I. B. shortly. 

Deputy Director. 

lDP 8E6RET 69"1R9L NUMBER ·'14 .. fJB4-ft 

COPY '2.. '-( OF '-{ 7 copi[I""" 

PAGE I or PAGES 

'fOP SECRET FRSTII 
S UCO 

O.T.P. 

ROOKEX 

ROLLIOK 

-~17. 

RECOl1il.lENDATIONS AroPTED :RY L. S. I. B. TO IMPROVE 

THE HANDLING OF CERTAIN U.K. CYPHER SYSTEMS. 

(a) Highest priority should be given to the investigation 

of further improvement or the alarm system bearing in 

. mind that the machine is normally handled by average 

personnel rather than by experts as in the f'ield trials. 

(b) The arrangement of the jack field should be modified 

{and any other appropriate alterations made) to obviate 

errors arising from Vlrong connections resulting in the 

transmission of plain languaee tape. 

In future the "m" copy or all one-time-pads used 

for Sigint communication should have the bottom righthand c01•ner dipped in red dye. 

Apart f'rom strict attention being paid to training 

and supervision no further recommendations are ma.de 

since the introduction of the mechanical modif'ica.tions 

should effect the necessary improvement in security. 

,.. 

A set of operating instructions with security sections 

suitably highlighted should be issued. 

T8P SE6RET 66NlROL NUMBER 54 ~8~lt;_ COPY :z. Lf Of 4 Z. COPIES 

PAGE ~ OF j _:PAQ£1 

TOP SECRET FROTII 
,.,. .. 

Date e'f' 

Compromise 

22.12.53 

23.12.53 

1:~~l: i.':1:1" : II :wil:: t:~\!'i) :'J) (~,,~·~'.: 11, ~~~~~~~~~ 

DGC/42.17• ;_-., 

A-ePend;j;g 

COlil?ROMISES OF SIGINT CODE'JORD Al'ID/OR MATERL'J.. 

Circumstances 

Message transmitted by 

radio in clear over 

5UCO by 2 Wireless 

Regiment, ~a.ma.gusta. 

Operator's error leading 

to "\ransmission of P/L 

tape being used to 

test circuit 

) 

g 

Classification 

SECRET 

codeword 

TOP SECBET FROTH 

CONFIDENTii!L 

Subject Matter Relllllrks 

EO 3.3(h)(2) 

Pl 86-36/50 USC 3605 

Check E:r.d repeat bf two 

words for corruptic:ms 

(of no significance.out 

of context) but incl.;uding 

oodeworC. 

l 

Poss~bili ty of 

interception cannot be 

discounted although 

the ROLLICK is a VIF 

point to point 

system, the codeword 

must therefore be 

considerad compromised 

"\.ction (other t 

disciplinary) tclc 

to prevent recur 

0.C. 2 W.R. 

attempting to dev· 

routine to preven 

cross-pa:tching. 

"""dditional methods 

for prevd?lting such 

error under 

consideration. This 

being a manual 

transmission the onl.y 

satisfactory answer 

is strict circuit 

discipline. 

None, as the cause 

was due to the 

"i.ssistant Ciroui t 

Controller failing 

to check on the 

mechanism a.fter 

changing the key 

tape.