RE 

Q ~,P'ttl'P'<)r:;=-l"'--

f4rai} i:.~ rr "'· s 

NATIONAL SECURITY AGENCY 

WASHINGTON 25, D C 

Colonel Bruce W. Bidwell, USA (Ret.) 

Office of the Chief' or Military History 

Room l.D6351 The Pentagon 

Department of the Army 

Washington 251 D. C. 

Dear Colonel Bidwell: 

Serial: 

8 

C0724 

NOV 1i'64 

Receipt of your letter ot 2 November 1954. is acknowledged. 

I concur with General Mauborgne in thinki.Dg that some mention 

of the collaboration with t.lte British in the communication intelligence field would be varranted in your history of the Milita.ry 

Intelligence Division and I therefore enclose a brief statement 

pertaining thereto. 

I 

It rray be that General Ma.uborgne "feared tbat the ?ia.vy was 

about to send over one of these ma.chines and steal Arar::f thunder" 

but this is certain'.cy not in accordance vith the account contained 

in the official ASA history, nor is it in accordance with m:1 quite 

clear recollection of the events in question, gained from firsthand contact with them. Indeed, '1111' recollection is that the Navy 

was quite reluctant about the whole business of collaboration and 

bad to be persuaded more or less to go into it. In any case, I 

think tba.t pa.rt of the stoey of small consequence and I hope you 

will agree in the propriety ot omitting questionable data ot that ' 

sort. 

' - . Thank you tor your iDformation rega.L"ding Fabyan and his 

auth0rsh1p. ~e situation is as I eXplained to you on the tele:. 

phone: he never wrote anything but letters; he had the writings 

ot others copyrighted in his name--. 

'I ;. ... f ""' ( 

~ I reiterate that we would like very- much to have a cow 

or two of your history when it is issued~ these to be ~ar our 

otticial librar,y? 

Incl: 

a/s 

• 

, 

Sincerely, 

qu~~~ WILLIAM F. FRIEIW.M 

Special Assistant 

SECRET 

Declassified and approved for release by NSA on 05-16-2014 pursuantto E .0 ~ 1 ~52a 

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REF ID:A72892 

SECRET l10124 

s ,~av 1954 

Discussions between the Army and the Navy in regard to cryptanalytic cooperation with the British began in the summer of 1940, 

and after detailed consideration of the matter the Director ot Naval 

Communications and the Chief' Signal Officer recommended to their 

respective superiors that a mission consisting of' two officers from 

the Army Signal Intelligence organization and two f'rom the Navy -- Comanmication Intelligence organization be sent to U>ndon to initiate~~ . ..:·<.... 

collaboration. The recommendation was accepted and in January 1941 

the mission lett, taking with them two "Purple" ma.chines, data for 

employing them in reading the Japanese highest-level diplomatic 

traffic, and certain other material. (The Japanese "Purple" cryptosystem and machine had been solved by A:I:my cryptanalysts headed by 

Mr. Friedman; this was a teat the British cryptanalysts had given 

up.) In exchange, the U.S. got from the British much valuable 

iDf'orma.tion in connection with German and Italian systems. Arm:! 

and Navy collaboration with the British began on an active basis 

soon thereafter and reached the point where in 1944 the two Services 

were in touch by radio, on a daily 24-hour basis, with the British 

organization. .Agreements were entered into between the u.s. and 

the U.K. whereby the U.S. had primary responsibility for communication 

intelligence activities in the Pacific,, the U.K. had similar responsibility in the Atlantic and in Europe. Resu1ts and technical. data were 

exchanged freely, under certain strict controls. 

SECRET 

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