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LOS( 53 )/OR/RJ . (Final Draft) 

UK/US COMMUNICATIONS SECURITY CONFERENCE 1953 

Report of the Qperationa.l Requirements 

Sub-Committee 

to the 

Executive Committee 

TRANSMISSION SECURITY 

The .Ope.rational Requirements Sub-Committee considered the Security 

Sub-Conmittee's report to the Executive Committee on Transmission Security. 

2. It was noted that this was the first occasion on which the general subject 

of Transmission Security had been discussed at a UK/US ConmtUlications Security 

Conference. Although considerable difficulties in meeting the security ideals 

set forth in the above report by the Security Sub-Committee were foreseen, the 

Operational Requirements Sub-CoIIllilitt~f'.% ;j~e~nd recommended that 

the action proposed in paragraph 3~of the report 

11 

Rhould be taken without delay) 

3. With reference to para.graph 2g of the Security Sub-Committee's report it 

was noted that automatic traffic flow security was currently being 

certain cases by the use of Apparatus 5 UCO No. 1. 

2nd November, 1953. 

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6eclassified and approved for release by NSA on 05-21-2014 pursuantto E.O. 1352a 
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LCS,53)/0R,/R(2)(FIN.AL) 

9t'h November, 1953. 

Copy N0. 

UK/US COMMUNICATIONS SECURITY CONFERENCE 1953 

11 

Report of the Operational Requirements Sub-Committee on 

Combined arid NATO Requirements for Facsimile Security Equipments 

and for CrYJ?tographic Systems for Meteorological Traffic 

A. Facsimile Security 

, 1. The Sub-Committee took note that there would eventually be a combined 

UK - US requireoent for Black/1Rhite facsimile transmission by secure means 

over long distance H.F. radio point-to-point circuits as well as by broadcasts. (There was no requirement. in respect of NATO so far as could be 

stated at present). 

2. CIFAX 

• 

a. It was noted that the question of combined technical standards for 

facsimile equipment was under consideration by the CAN-UX-US 

communieations equipment panels, a,nd whilst some agreements had 

been reached there were no complete combined.standards for facsimile 

equipment. The question of combined CIFAX was therefore rather 

difficult at this stage. The following technical standards would 

have to be established before a combined specification for 

CIFAX could be drawn up:-

g 

3 

4. 

5 

6 

7 

8 

Size of picture. 

Definition required • 

Index of co-operation of FAX equipment. 

Time allowed for transmission of a picture. 

Frequency band of radio Connnunications systems 

Type of transmission system. 

Crypto system. 

Communications plan for usage of CIF.A.X. 

The Sub-Conunittee agreed; tha~ (1) through (5) were already covered by. 

the C.AN-UX:-US J.C.-E.C. deliberations; but made the foll:JWing recommendations 

on tie remainder. 

b. 

c. 

Type of Transmission System 

. Whilst it is understood that the J .. C.-E.C.'s had already agreed 

that multi channel SCFM was the best.method of transmission for 

CIFAX for other than short distances ground wave H •. F .. radio links, 

the Sub-Committee recommended that "ihe E:it:ecutive Conunittee should 

be asked to invite the Communications Equipment panels of the 

CAN-UK-US J.C.-E.C. 1 s to agree a technical specification for a 

multi channel SCFM transmission system for combined use in conjunction with CIF AX. . ' ,, 

Type of CrYJ?tO System 

The Sub-Committee noted that both the U .s. and the U .K. had 

specific projects for black/white CIFAX under test, but it was as 

yet too early to consider one to meet combined requirements. ,The 

ohly conunent which could be made at this stage was that such a 

system must be reliable in operation and present no undue 

maintenance problems •.. . ' 

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de Commup.ications plan for using CIF.U 

The requirements of equipments and 'volume of traffic were 

estimatea to be:-

U.K. 

I 

·.b.ir Ministry Meteorological Office 

Some point-to-point circuits. 

Single transmission broadcast on3 frequencies each 

to 20-40 receivers. 

64 pictures a day frQm each transmitter would be 

adequate. 

Rnyal Navy 

Some point-to-point circuits. 

2 or more Broadcast systems each with 1.2-20 

"receiving only" stations envisaged at the moment 

but a further requirement is possible. 

64 pictures a day from each transmitter would be 

adequate. 

The U .K. requirements would involve point-t0-~;;i0int .circuits to 

North illl1erican and European Stations; but mainly broadcasts 

from Dunstable. 

On the Continent e. fmfl score receivers viould be necessary, all 

receiving continuous transmissions. 

8 point-to-point circuits. 

Probably 7 broadcast stations each with 12-20 

receivers. 

48 pictures a day from each transmitter. 

Air Force 

The u.s.A.F. requirements involved up to ten con- . tinuous brQadcast facilities each with approzi.mately 

20 "receiving only" stations. 

There is also a requirement far up to a hundred pointto-point secure facsimile circuits. 

3. There was a. general requirement in the Navies t0 read broadcasts from both 

nations. In the i;.ir Forces this was not s.'.:l imuortant but it was considered 

desirable to standardise equipment so as to make intervvorking possible if 

required. 
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~. The Sub-Committee recommend that reports of the trials carried out on 

Mountebank, AF'S.JW 700 and .hFS.AX D .503 sh~uld be exchanged when available. 

i 

B. Cryptographic System for .Meteorological Traffic 

5. Statement of Requirements 

The Sub-Committee reaffirmed the Combined and NATO requirements 

for weather controlled information transmitted by radio, as set out in the 

Report (WCS/R(2) FINAL) o.pproved in the UK/US Communications Security 

Conference, 1952. These requ:irements are listed below: 

a. Continental and Sub-Continental weather Broadcast via CW. 

(Off-line crypto-equipment needed.) 

b. Weather ~ortion of Naval general (admin.) broadcast. 

(Off•line orypto-equipment needed). 

c. Theatre Operational Weather Information disseminated by Commands 

to tactical units. (Preferabl.,y same crypto principle used •• in 

para. a.). 

d. Continental an:d Sub-Continental exchange of 'leather Data on RliTT Pt 

to pt circuits. (On-line orypto-equipment needed ). 

e. Collection of Data from Ground Reporting Stations by CW 

(1) Intra-national only. No Combined and NATO requirement. 

(2) Between Stations of different nations. (Off-line cryptoequipment needed. One-time pads will suffice where traffic 

load does not exceed 3000 groups per day). Same off-line 

crypto-system as for a. above. 

f. Weather Reports for Aircraft 

g. 

(1) Reconnaissance (Off-line cryptosystem. One-time pads will 

meet this requ:irement). 

(2) Combatant mission - no special weather system required • 

. (3) Non-Combatant mission (preferEblY will be pa.rt of 

operational cryptosrstem). 

Weather Reports from Ground t~ Aircraft - (Includes requests 

for weather from aircraft). 

Landing weather and IN-flight weather. OFF-line system needed. 

UCO has been accepted for Combined use on nn interim basis for 

multi-seater aircraft. 

6. Present Status 

Papers have been introduced in the CAN-UK-US J.C.-E.C. 1s covering 

requirements in a, b, c, e, f'(1) am g above. These papers provide inter alia 

f'or the use of CCM as the off-line cryptosystem. 

7 • CCM and Met. Qrypto Plan 

As there was no objection to the use 0£ operational rotors with MET Key 

Lists,. it was agreed that, taking all factC\rs int~ consideration, 1st July, 19.54, 

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could be trea,ed as a reasonable date by which CCM can be in position world• 

wide for Combined and NA.TO Meteorological trafficl For reasons briefly 

explained in the next para. however the Sub-Connnittee recommend that the Met 

crypto plan as outlined in para. ~ sh~uld so far a~ possible be implemented 

by 1st May, 1954. 

8. Interim System 

Consideration was given t" the argument for an inter~.m cypher system 

pending the introduction of CCM for MET in the event of war occurring during 

the intervening period~ In this event intense aerial activity on both sides 

would be a feature of the early phases of a general war. It was therefore 

necessll!"y that security should be provided for MET information. It was noted 

that the S.S. Frame system could be made available by the U.K. for this 

purpose,_ but the date by which the S.S. FrN11e system could be in position 

world-w:i.de wr>uld be only a few weeks bef Qre the COM. It is considered inadvisable to place an interim system in position for s,., short a time and 

moreover the distribution of the S.S. Frame would retard the distrfbution of 

the CC.I. It is therefore recommended that all efforts should be concentrated 

• on putting the CCM into position by the 1st "May, 1954. It is noted that in the 

event of an emergency arising in the meantime, the S.S. Frame would still be 

available for issue to NATO with very little delay. 

9. One-Time Pads 

The Sub-Committee recommended that st,,cks of pads should·be built up 

'with a view to implementing the MET. Crypto plan by 1st May, 1953. 

10. . _ON-LINE CYpher . facili t:i.:es· 

To provide such facilities. for certain trunk RTT circuits shown in the 

·.integrated .MET Communications Plan, approximately 30 duplex terminals in the . 

. Atlan'f;ic area e.lone should ideally be operated in Wartime. At the moment only 

. • ... 2S AS.AM 2-1 machines can be ma.de available (for non-synchronous operations). 

· > It is not ad'V'ised that these should be used on-line on radio circuits but they 

can be used off-line with very little delay at the expense of additional 

· · bandling effort at the terminals. They should be retained as a.n interim 

.. · provision f"or an emergency although they are not a satisfactory method of 

>"handling the traffic; synchronous on-line equipment is considered essential. .• 

The CAN-UK-US J.C.~E.C.'s are currently considering the detailed statement 

. i. , ol the meteorological camnunica tio:i;is requirements prepared by the NATO Met • 

. OOumittee• When these are agreed, the appropriate Communication Security panel 

. . -~ tn.e J .o. -E.C. 's will make a more detailed recommendation as regards ·· ·. C1"3'P~-systems • 

. ' 11·. !QQ 

;;. . .lt.t present "UCO" is the only system available to meet the c,,mbined and 

-· · · .:llA!OO -requirement for the transmission af weather infr.>rmation to multi-seater .- '.'. - ~creft in flight. It is recommended that stocks of daily letter scrambles 

.·~ ·r: .. .thould be made available to enable UCO to be in position by 1st May, 1954. 

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