USCIB: l3.5/6S 

24 May 1954 

TO!I S:t!leRF.l'l' 

MEMORANDUM FOR THE MEMBERS OF USCIB: 

Subject: Com.promises or COMINT Codewords or Material. 

l. Attached for your information is a memorandmn. from 

the Secretary, I.SIB, outlining ISIB action in regard to 

security violations due to ineffective COM.SEC practices. 

2. The recommendations by GCHQ concerning specific 

British cryptosystems mentioned in paragraph 3 of the 

enclosure have been circulated as an enclosure with 

USCIB 13.5/55 dated 20 April 1954. 

3. THIS DOCUMENT CONTAINS COMMUNICATIONS INTELLIGENCE 

INFORMATION AND SHALL BE HANDLED ONLY IN CHANNEIS EXPRESSLY 

FROVIDED FOR COMINT. 

Enclosure 

Copy of I.SIB Memo 

date~ 6 May 1954 

REPRODUCTION OF THIS DOCUMENT IN 

WHOLE OR PART IS PROHIBITED EXCEPT 

WITH PERMISSION OF THE ISSUING 

OFFICE. 

USCIB: 'JJ.5/68 

'FOPSBGRBT 

Declassified and approved for release by NSA on 02-12-2014 pursuant to E.O. 1352e 
Executive Secretary, 

~~ ID:A59418 '1'0~3nC1lET e 

Oakley, 

Priors Road, 

Cheltenham., 

Glos. 

LSID/119/54 

6th May, 1954. 

United States Communications Intelligence Board. 

COMPROMISES ot SIGINT CODEWORDS AND/OR MA'!'ERIAL 

L.S.I.B. acknowledges receipt of five copies of U.S.C.I.B. 

Directive No. 9, published in accordance with paragraph 46 of Appendix 

1

B' to the UKUSA Agreement. Similar instructions are being incorporated in the new version of IliSIG which will be issued shortly. 

2. In accordance 'With the provisions of Appendix 1B 1 the 

Directors of G.C.H.Q. and N.S.A. have from time to time exchanged 

details of the various instances of misuse of Sigint communications 

from which it might be assumed that information had been com.promised. 

Through its concern at the large number of such misuses L.S.I.B. charged 

its Security Connnittee, last July, with a review of the causes of the 

errors occurring on U.K. cOilllllunications. 

3. This review led to a list of recommendations designed to 

bring about an improvement in the situation; these recommendations 

have been formally adopted by L.S.I.B. and are being implemented by the 

authorities concerned. A copy of the recommendations is attached at 

Appendix for the information of your Board. Certain further recommendations concerning specific British cryptosystems have been communicated 

by Director G.C.H.Q. to Director N.S.A. 

4. L.S.I.B. is pleased to note that the attention drawn to 

this subject by the review appears to have had some effect on the U.K. 

users at aJ..l levels. 

5. L.S.I.B. welcomes the revised instructions for the ASAM 2-1 

cypher machine - the misuse of which had been responsible for a number 

of compromises. 

6. , L.S.I.B. intends to keep this subject under continuous 

review and is confident that u.s.c.I.B. will take corresponding action 

in view of the dangers to the common effort inherent in the misuse of 

Sigint communications. 

PL 86"""36750USC3605 I I -¥'J'i'H0P~S.L#i-.~IPW'F/E'-#iJ.'q:;Lf: ucez com J 

:CO~aon Signal Intelligence Board 
. ., 

'i'OP SEIHi' LSIB/119/54 

APPENDIX 

RECOMMENDATIONS RELATING TO COMPROMISES OF 

SIGINT CODEWORDS ANDlOR MATER:W;I. -

1. It is essential that personnel employed as Sigint cypher 

operators should be specially selected to conform to high standard of quick-wittedness and that Departments and G.C.H.Q. should 

select personnel 'With a view to ensuring that the right type of 

man is employed. Particular attention should be paid to the 

calibre of cypher operators posted overseas. 

2. Every effort should be made to maintain the highest possible 

standard of training and particular attention should be paid to 

supervision in all cypher offices where Sigint is handled. A high 

standard of discipline must be maintained together 'With an equally 

high standard of security education. 

3. Decisions concerning disciplinary action should not be taken 

too hastily and should be made appropriate to the proportions o:r 

the o:r:rence. All o££ences should be immediately £ollowed by a 

formal investigation. 

4. Security sections and highlights o:r 11do 1 s" and "don1ts 11 in 

operating manuals and other cypher documents should be 

(i) 

-~'.~ 1/ 

(ii) 

(iii) 

Printed in heavy type, or -~ 

Printed in red, or 

Extracted and shown on inside covers. 

5. Constant attention should be paid to the efficient mechanical 

and electrical working of cypher machines since the standard of 

maintenance performed has a direct bearing on cypher security. 

6. Greater use of displayed slogans should be made on machines 

and desks. It is appreciated that the effect of slogans is limited 

by familiarity but their use should be investigated. 

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