'l'OP SBSH£1? St",NE>E SESOO'FY INFQW11.'IlON 29 July 52 

MEMORANDm1 FOR GENERAL CANIME 

SUB~CT: Heasures for Increased Security of com:NT 

l. The recent failure of USCIB members to agree on the subject 

proposals of the Security Committee with respect to the plain text 

security problem suggests the need for a fresh and possibly different 

approach to a solution. The tendency in the past has been to generalize 

on security objectives and perhaps not examine closely enough exactly 

what must be protected and 'What it is really feasible to protect. It 

may be well, therefore, to review our reasoning in this case. 

2. In the safeguarding of. COMINT which results from cr;yptanalyliic 

processes (including solution of call siens and procedure systems) or 

£rom the interception of traffic which is sent in complex transmission 

systems with secrecy or privacy features, we have two facts to conceal: 

.first, that we are in possession of certain information not intended 

for our eyes,, and, second, that we are in a position to obtain more or 

such information in the same manner. The degree to which we must conceal these facts depends, of course, on the nature or importance of the 

information in our possession and the difficulties of acquiring it. In 

most cases, disclosure of the mere fact that we can read a cryptographic 

or other secret transmission system is sufficient to result in prompt 

countermeasures to deny us further access. 

3. In the case of plain text, the situation is somewhat ditferent. 

A message may be sent in clear because the sender: 

a. Is not concerned with who reads its 

be Is not aware of' its sienificance when-synthesized with other 

information available to the interceptor; 

c. Makes a mistake; 

d. Violates a regulation; 

e. Has no other means of' transmission; or 

r. Is not a.ware that the transmission can be intercepted by 

1.D'lauthorized persons. 

4. The problem of maintaining comm:unication security f'rom the 

sender's standpoint then reduces to one of e:icercising widespread surveil- 0 

lance to ensure that the foregoing things do not·occur in the transmis- l9 

sion of information which unauthorized persons must not receive. In a 

Declassified and approved for release by NSA on 04-09-2014 pursuant to E. 0. 1352B 

COPY #__.L=lJ __ 

ARMED FORCES SECURITY AGENC~1-Fo~ ~~t-~tosc TOP SECRET CANOE 
- "' 

29 July 52 

SUBJECT: Measures for Increased Security of COMINT 

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

vast colTD!lunication complex:, such as that or the Russians, this security 

problem is a very difficult Qne. If insecurityresul.ts from 0%7Ptographic or transmission system faults, a proper change in the s)'Stem 

will correct any leaks wherever they may exist. I£, how.ever, leaks 

occur through plain text transmissions, it is first necessary to determine the seriousness of the leak and then the exact source or cause. 

The first question involves determining exactly what infOrma.tion is being 

derived by the interceptor. This will establish the latter's abilit7 to 

exploit plain text traffic through information s;ynthesization. Corrective 

measures can then be taken by the controlJ.ing authorities to revise regulations or procedures so that certain tl'Pes of information are prohibited 

.from being sent in clear. The'second question involves determining the 

office of origin or the exact circuit or means by which the information 

is being transmitted. Only in this way can carelessness, vio1ation ot 

instructions, unawareness of accessibility, and simi~ sources of' leakage be corrected. · 

5. If we are to combat successfully this ldnd of surveillance, it 

follows that we must deny to target nations knowledge of the results of 

our plain text synthesis or collation and knowledge of the p~ecise .source 

of information which we obtain. The general fact that we are in a position · to read plain text traffic and to intercept plain text messages which are 

sent by channels which it is conunonly known can be tapped obviousl7 requires no special concealment. 

6. Our current difficulties in the maintenance of security for our 

plain text COMINT operations stem principally from two facts1 

a. large n'l.Dllbers of personnel are required for processing, and, 

according to current regulations, they must be cleared and indoctrinated prior to employment; 

b. The vaJ.ue of plain text COMINT is grea.tly reduced unless it 

can be fully synthesized with information i'rom non-COMINT 

sources, because the plain text items frequently become 

significant only when related to other facts. 

We ai:e thus faced with. the necessity of somehow reducing the number of 

persons that must be cleared ancl indoctrinated, and of somehow providing 

a COMINT product which can be more widely used without increased jeopa.rdJ' 

to the source. 

-2-

ARMED FORCES SECURITY AGENCY FORM 781-ClOSC 

18 JUL 51 

COPY# l.J 

TOP SECRET CANOE 
... 

29 July 52 

SUBJECT: Measures for Increased Security of COMINT 

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

7 a It would appear that at least. a partial solution of the problem 

might lie first in a division of the work into two or more processing 

levels, with different security requirements for each, Thus we might regard collection {especially from open sources) and initial screening as 

operations which do not generally reveal the true importance of the information derived nor the exact source of specific items or inportance, 

and, nence, as operations which do not require the same security standards 

as do later processes. Subsequent operations, wherein the bits and pieces 

a.re drawn together and their significance is established, Bl'e where the 

tight security measures must begin. In the processing of material as 

COMINT, it is usually essential that the exact sources be known to the 

analysts and security measures must be applied accordineJ.y, This presents 

no special problem if the work is conducted in a C01'1INT agency, such as 

AFSA, since the same security measures are required for other operations 

as well. Beyond this point, however, the real difficulty a.rises, and 

there some further means must be found of lessenlll.g the need i'or certain 

of the restrictions that are now in force, 

B. After processing of the material as COl'UNT, it has to be thoroughly collated with other material from non-COMINT sources if its full value 

is to be realized. iberefore, J.f we are to minimize the increased hazards 

introduced by this additional processine, two precautions must be observed: 

a. To avoid pointing to klnds of information which the Russians 

mieht to their advant~ge bar from plain text messages, such informa. tion which is of great importance to us should continue 

to be handled mider stringent restrictions. 

b, To avoid assisting the Russians in their surveillance problem 

by pin-pointing leaks for them, other material should be passed 

out either in disguised form or without any indication of the 

exact origin or source (but with appropriate classification and 

source grading}. 

The latter is a common procedure in the dissemination of agent information 

where the precise source must ·be safeguarded if the agent is to remain 

alive. It is not lll'lUsua.l in the case of this type of information to withhold. the name of the agent, his contacts, and the combination of the safe 

from which he obtained the information. Unfortunately, however~ these 

are the very kinds of facts which are frequently demanded by CONINT consumers and which represent a serio~s hazard in dissemination of plain I 

-.3- COPY #__._l.3.-..__ 

ARMED FORCES SECURITY AGENCY FORM 781-C10SC 

18 JUL 51 TOP SECRET CANOE 
"'"" 4- I •• 

~p SEeR_Ep-~ Tblll document Nm only b:y tb- permnnel o~ally ::..:;:.w.: i::-~ with eo111-

1DllDicati011 lntelligenGe MC!lrit:y NsU!atiOllll iand authorised to receive the iDformataoa reported b.enila. 

29 July 52 

SUBJECT: Measures for Increased Security of COMINT 

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

text information. There is undoubtedly a certain amount of justification in 

the consumers' attitude. Nevertheless, one is unhappily forced to the con• 

clusion at times that their demand probably results largely from the fact 

that there are now in the consumer agencies many ex-members of the producer 

agencies who are unwilling to abandon the fascinating art which they once 

practiced or are unwilling to rely upon the analytical powers and judgment 

of other practitioners. If this is indeed the case, there is some doubt as 

to whether these ex-producers are now in the right end or the business. 

9. Obviously,, any solution along the lines suggested above would require some concessions by way of compromise. The consumers would have to 

modify their requirements and possibly accept more material in tabulated 

or other summary form. The producers would probably find it necessary to 

change the form of certain of the:ir reports. Prompt services would have 

to be afforded consumers when' verification or ~lification or reports is 

required. Some information might even be lost to consumers (although this 

could be a modest price to pay for maintaining the flow). 

10. Whatever the case may be., something will have to give way if the 

present impasse is to be overcome., for we cannot have our cake and eat it 

too. If workers cannot use a product as required for best results., perhaps 

some change can be made in the workers., their work., or the materials they 

use. This is an approach to the plain text problem which may not yet 

have been adequately investigated. It sho~d certainly be tuJJ.y explored 

before any additional risks are assumed. 

Copy to: 

Chief 1 Office of Operations 

; . 

ARMED FORCES SECURITY AGENCY FORM 781-ClOSC 

18 JUL 51 

COPY #__.....13 __ 

TOP SECRET CANOE