REF ID:A65503 ., .. 

~~~.,LUc;;.;JQ..Jf~ 

~~JJ____ 

Declassified and approved for release by NSA on 04-25-2014 pursuantto E.O. 1352a 

... '"' - - REF ID:A65503 

1'6P SBEJHm! 

6 Jum 1945 

MEMORANDUMS Major James C. Taylal." 

SUBJF.CTs The Relationship of Japanese T/A to the Security Problem 

1. In April 1944 Japanese T/A at SSA (B-4-C) concluded from available 

Japanese Army bulletins that the Japanese possessed a Signal Intelligence Service which was actively engaged in performing T/A on Allied Army- and Navr 

Communications. A memorandum was Sllbmitted to Col. Corderman setting forth 

the results or this preliminary investigation and ultimately the gist or this 

memorandum was incorporated in a study- prepared by Capt. Rhades on Japanese · 

signal intelligence operations. 

2. Thereafter a member or the Japanese Military Crypt Branch (Capt. 

Raskin) worked with the Security Division with respect to breaches of both 

cryptographic and traffic communications security. Al though members or the 

Japanese T/A section cooperated in this venture, it was felt that Japanese T/A 

section ahaald participate activel7 in the evaluation of evidences of traffic 

analysis by the Japanese on American communications, since the Jap T/A section 

was engaged in deriving intelligence from enemy traffic and was in an excellent 

position to evaluate the techniques emplCW9d and suggest possible countermeasures. 

3. In January 1945, B-4-0 invited attention to the apparent success of 

the Japanese in using :bratf'ic analysis to predict B-29 raids over the mainland. 

Pursuant to this memorandum. a conference was held with Col. Huddlsson., •jar 

J. c. Taylor and others providing for the submission to .MIS or all available 

material in connection with these raids. T~ minuws of this meeting dated 

10 February 1945 concluded with the following statements 

"1.he parpose or this memorandum is to act as a work• 

sheet for following through on the various measures presented 

herein, and to assure that all possible information available 

within the Japanese milital.7 tratf'ic analysis section is presented to proper authorities in MIS. It also endeavors to 

bring to attention the possible contributions or T/A personnel 

engaged in analysis of eneD17 activities and therefore such personnel might be of' considerable assistance if empl.pJed b:y 

missions on security.• 
' REF ID: A65503 

4. In April 1945, the Japanese T/A section was invited to work with 

Major John D. Spitzer or the Political Reports Section of' MIS and with members 

of A and C Branches of the Security Division of ssA with respect to Japanese 

success in deriving intelligence from Allied communications. Although the 

Security Division extended all cooperation to this team-working in the f'orm of' 

liaison 1 t was unable to supply personnel to work on the material on a da7-to-da7 

basis. Members or B-4-C commenced working with Major Spitzer at the Pentagon 

specifically with respect to Japmese use of 'J:/A in analyzing Allied commnication. 

5. A study was concluded on the activities of varicos Japanese signal 

intelligence agencies engaged in analyzing Air Transport Command traffic transmitted in conjunction with fiights over the Hump. A .further stu~ is nOR in progress analyzing the traffic analysis activities of tm Second Area Army at Pinrang 

in conjunction with Allied Transport and Bomber acti"1. ties in the New Guinea-:MEI· 

PI Area. Both studies are being conducted by B-4-C personnel working tull time 

with Major Spitzer. Members of the Securi't1' Division provide collateral data 

needed to determine the correction or the Japanese inferences. 

6. To clarify the respective divisions of labor between MIS. Securiv 

Division, and Intelligence Division a meeting was held at Major Spitzer1s office 

on 3 June 1945, at which were present Major Spitzer or MIS, Capt. Maass, and Lt. 

Beimers or the Security Division and Lt. Barasch and Lt. Burcum of tbe Japanese 

T/A Section of the Intelligence Division. The discussion resulted in the following conclusions t 

a. The task of "evaluating" Japanese success in cryptanalysis and 

traffic &.na.o/Sis is properly divisible into the following categories: 

1) t:. ~ assemblage of the complete information of the Japamse 

results and their explanation in terms of standard T/A techniques is to be the 

primary responsibility or the T/A section of the Intelligence Diviaion_J 'l11e responsibility' is so imposed because the Jap T/A section has available to it (in 

conjunction with B-1 and B-2) the complete history of the workings of any Japanese 

intelligence center, whether or not the results reach translated form, and can 

make judgments from raw traffic even if not decodable. Moreover, because of' the 

nature of its activities the T/A seqtion is in the optimum position to determine 

how the Japanese make their inferences and can suggest possible counter-measures 

based on their experiences with enem;y traffic. 

2) )(!""'The identification of the Allied cryptographic system or 

communications practice reterrtd to by the Japanese and the determination of the 

correctness of the Japanese conclusions .is to be the prim81'7 responsibility of 

the Security Division, since this unit has access to the actual cryptographic 

systems and the communication practices employed as well as to col.lateral intormation (including any possible deception program wM ch may be used). 

9?9P SB0ft1iJ! 

2 
REF ID:A65503 .. 

3) L The determination of the correctness of the inf"ormation 

reported by the Japanese with respect to battle order, disposition, subordination, 

and operations of Allied troops is to be the primary responsibility of MIS, since 

it has access to such information. 

b. ~When the three phases of 11e"'1uation• are completed, reco111111endations 

tor corrective action are to be made jointly, and the result, written up in ueeable 

form tor the theater commander, is to be disseminated through established IvIIS 

channels. 

c.1 The process of evaluation and corrective recommendations is to 

be applied to communications not only or a War Department echelon but to those 

employed in the Theaters, since the knowledge of such possible breaches or securitJ' 

their evaluation and possible corrective action may be available only at Washington. 

d. To implement these suggestions it was recommended by B-4-C representatives that MIS, B-4-C, and the Security Division set up facilities to act as 

a unit, such facilities to be established at SSA. Various queries were raised to 

such proposals Major Spitzer was willing to participate in such venture, particularly because he felt that it was advisable to work at the source or the 

material, at SSA. Although he believed that Gen. ClarlB'.8 directive imposing responsibility in MIS for the evaluation and dissemination was general enough to permit the implementing or this suggestion, he stated frankly that the policy or some 

members of C Branch was opposed to working on any evidences of Japanese success with 

8.IJ1' cryptographic systems or communications other than War Department, and that he 

felt that it would be disasterous to the agreement tor all units concerned to work 

on this material if' the persons in charge were not sympathetic to the endeavor. 

He was willing, however, to set up such working at SSA under Mr-. William Friedman, 

Director of Communications. Major Spitser expressed his willingness to participate, 

but did not belitve his imperiora would release him on a i"ull time basis. lmmbers 

of C Branch stated that they did not have personnel to participate in such venture 

on a full time basis, but were willing to cooperate by performing the duties stated 

in Paragraph 6 A 2 above, and that they could not obtain the consent of their superiors 

to work in a new unit, as suggested. 

e. It was finally decided that B-4!90 would work with Major Spitzer, at 

the Pentagon, or at SSA if space could be obtained to perform the first· stages of 

evaluation, as discussed above, and that the Security Division would cooperate in 

tha manner stated above, but working on a liaison basis. 

OJ..~ Q-~~e/N Clarence :f.' c>Barasch 

lat Lt., Signal Corps