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Copy No.: I 

LCS (53 )/N/R/1 

UK/US COMMUNICATIONS SECTJ.d.ITY CONFERENCE 1953 

Report of the Engineering Committee - Phase I 

to the .Executive Committee 

1. In accordance with the rec'lmmenda.tion of paragraph 11 c (1) of the Report 

to the British Chiefs of Staff and the U .s. Joint Chiefs ..,f Staff of the UK/US 

Communications Security Conference held in Washington in May-June 1952, the 

Engineering Committee has prepared data sheets for each equipment available or 

under development, and has made recommendations on certain salient points. 

The recommendations which follow are based :')n observations made and informal 

discussions held during the fortnight reserved for this purpose prior to 

Phase I of' the 1953 Confercnc~. 

2. The Engineering Crnnmittee viewed equipment where possible and held 

discussions on the following: 

Literal Off-line Crypto Systems 

On-line teletypewriter Crypto Systems 

Ciphony Systems 

Cifnx Systems 

Spuril'>us Emissions which endanger Communicatif}ns Security 

Crypto Milterial Production Equipment 

Security Systems for I.F.F. and Navigation~l Aids 

General Review of new electr~nic tachniques. 

3. For ready reference by members of the Executive Committee and by those 

attending Phase II of the Conference, a tabulated list of pertinent 

characteristics of the various equipments has been prepared. Since some of the 

data is subject to confirmation, it is nQt intended that this tabulation should 

form part of' the final report of the C~nference. 

4. The major rec~unnendations of the Engineering 0')TI!IDittee aro: 

A. Future Gombined Research and Development Effort 

There is considerable similarity bet-vreen the S?ecific R & D projects 

being pursued by the U.K. and U.S. Alth~ugh this means duplic~tion of effart in 

some instances it is not necessP.rily wasteful duplicati•)n. On the contrary it 

assures protec~ion ~f national interests, and the healthiness of inde?endent 

lines of investigation. However, this very similarity ?ffers an opportunity 

for effecting considerable economy of development res~urcos. The Engineering 

Committee believes that with more specific guidance on ~perationnl requirements 

from the Service Departments, economy could be achieved. This guidance, it is 

felt, should be in th~ f'orm of a. directory of CIJl?lbined and Nil.TO Crypt-:>graphic 

security requirements. The Dfrcct·)ry shoul1 :!.nclude alS•) listings of cryptoequipment and systems available or under development to meet the &tated requirements. It is r~c ..... nncnde·: th..-"C-':;:-

The Ex~cutive Committee consider the desirability of preparing such 

a directory alld the best method of effecting this. 

B. Progress in Electronics 

There have been significant advances in Electronics and Circuitry 

since the 1952 Conference. In the past, electronic techniques have, with few 

/exceptions 

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exceptions, been adopted only where the speed of operation would preclude the 

use of electromechanical methods. Electronic methods are now being explored 

for application to On-line Teletypewriter Cypher Systems and even to some 

off-line Literal Cypher Systems. 

It is recommended that the Service Departments be informed of this trend 

and of the fact that it will have a profound effect upon crypto-operations, 

supply, and maintene.nce as they are practised tn-day. Of these changes, 

those which affect the training of maintenance personnel are pr?bably the m . .,st 

difficult. Because of this, thought and planning should be started now by 

the Services if they are to be in a position to enjny the full benefit of the 

advantages offered by electronic crypto-equipm~nts when they bec~me available. 

C. Co-ordina t.ion o-f' Cryptographic an.d C·"'l'!'Tlm~:::0·~~£~ Egu:lpment. 

~lopment 

The present practice of almost independent development of cryptographic equipment and certain forms of communications equipment has usually 

led to incompatibility of one with the other. In order that compatibility 

may be achieved it is essential that such communications security as is 

required should be considered an integral part of the c~mmunications requirement at the time ·when the Staff and Operational Specificatir.ms and or 

Military characteristics are being formulated. This is necessary so that the 

cryptographic ~quipment may b0 designed to suit the requiremenlis of the 

communications system or, where necessary, the communicati~ns equipment and 

practices may be adjusted to make possible the utilisation of an acceptable 

crypt0graphic system6 

It is recommended that the necessary steps be taken to ensure that this 

course of action is adopted by all concerned. 

The development au·~hority must maintain close co-t')rdination with 

the User Services. so that the operating and maintenance requirements are made 

known at all stages in the development, Thus, Users may weigh the need for the 

equipment against tho m1intenance and training requirements and, if necessary, 

the development autho~ity may adjust the design to meet the operating and 

maintenance probleme 

It is recolJllllE)nded that there ~e consultation between the development 

engineers and the Service engineers and conununicators as early as possible 

in the process of development of each equip1aent in order t!l achieve these 

ends. 

E. Spurious Emissions which endanger Communications Security 

The Com.~ittee agree that radiation, conduction and induction from 

conununication anJ crypto devices are very grave s0urces of insecurity. 

~=-

Although investigations are by no means c1mplete it is recolillllended 

(i) All cryptographic Aquipment using teletypewriter ancillaries 

and/or sequential signalling of clear text or key be considered insecure up to a distance t)f o.t least 200 ft. in any 

direction from the equipment, unless the equipment has been 

specially protected. 

(ii) That all crypto systems and ancillaries be investigated at 

high priority, to protect them and ensure that appropriate 

rules can be formulated for their use and siting. 

(iii) Tha·t; future equipments be designed t·J be free from such spurious 

emissio!!s, 

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F. li1uture Engineering Discussions 

The fortnight reserved before the Conf'erence f~r visiting Establishments, viewing equipments and inf'ormal discussions between engineering experts 

hns proved of very great value to the .Engineers of the Service Departments. It 

is c~nsidered, however, that a better arrangement needs to be ma.de for the 

Engineers from the Research and Development Establishments to obtain detailed 

inf'ormation and to exchange views on techniques, etc. 

It is recommended that:-

(i) The assignment, on a semi-parmanent basis, of qualified . 

technical liaison officers to the R & D establishments .. ':ff 

one or both· agencies should be considered. 

(ii) Future Conferences .should provide a preliminary phase to 

enable the Engineers and Communicators of the Service 

Departments to visit Establishments, view and discuss 

appropriate equipments which are available and under 

developrr.ont. 

(iii) There should be more frequent visits, independent of the 

formal Conf'erences, by engineers of both countries in sP.J.'3.11 

parties to discuss specific problems or equipments. 

G. Exchange of Components and Models of Cr.ypto Equipments 

It is recommended that as a regular procedure each nation provide 

to the other, on an indefinite loan basis, fryr test and exnmination, engineering and first production models of components and equipments of mutual 

interest: and that if exchange is not practicable the equipment will be 

subjected to an agreed series of tests in the parent country. 

8, Palmer Street, 

London, s.w.1. 

29th October, 1953· 

PL 86-36/50 USC 3605 

OllU!LX lllWll 

Engineering Committee 

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