REF ID:~~~ft41 

•• NAVY DEPARTMENT 

OFFICE OF THE CHIEF OF NAVAL OPEHATIONS 

Washington 25, D. C. 

OP-20D/ef 

(SC) N36-lO 

Serial 00736P20 

From: 

TO: 

Subject: 

Chie~ of Naval Communications 

Chief, i'rm~~ Seeui•:J..ty Agency 

Reference: 

Co~..ments on Army Proposals Regard~ng the CCM 

(a) A.rm~ Security ~gency Statement on CCM - Conference with Navy on 1 pecember 1947 

1. It is appreciated that the Army is not in a posltion 

to undertake any changes in the present CCM until the SIGROD 

program has been completed. This, hovever, should not prevent the twq services reaching agreement and.firm commitments between themselves as to the future .program. It is believed 

that any new "CCM" n;tust_work with the improved ECM ·ccsP 2900) m.er~ly through insertion of the proper basket s.nd rotors.1 and 

setting an.Y switctiing arrangements permanently installed in 

the basic machine (ECM). Th!s debars too radical departure .from the present SIGROD/CSP 1700s or from the present SIGABA/ 

CSP 889. The Navy's rehabilitation and modernization program 

ror the ECM is _just beginning and changes can be made now. A 

year hence the Navy will be too far along in this program to 

accept alterations .. Consequently, an early, coordinated decision as to th~ future CCM for interim use, as well as for po·s- ·aible long-range use, is considered essential to the national 

interest. · 

2. -The Navy's Cryptographic Research program prescribed 

by the Chief of Naval Operations in May 1947 gives top prior+ty 

to the f9llowing three projects: 

·a. Modernization of existing equipm~nt. 

b. Adapting existing equipment to teletype and 

other rapid means of communication. 

· c. Imp1 .. ovement of communication secur~ ty. 

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Inasmuch as the ASA 1s· prohib'ited by higher authority.from 

attempting to improv·e existing equipment, 1 t would appear . ,logical for the Army to accept the Navy's qevelopments along these lines. 

3. The proposal for more frequent change of COM rotors 

·probably is impractical at this time for reasons of expense 

and lack C>f reserve rotors in ·both services. The twice daily 

chan.ge qf lceylists would be a. source of confusion and is 

therefore considered impracticable. 

l~. There are five pcssible programs for the Combined Cipher ., Machine ;t namel~r: · -·· ·- -

a. Continue with the present system, with which the 

U. S. Navy and British are dissa.tisf.i..ed. We do not feel that· 

the present COM has sufficient ~erent security for highly important secret messages. _The practical effective security· of CCM appea~s to· be reducing steadily. ·· .-

b. Use the Navy's improved. "CCI~" ri<>dificati.ons, in-

.eluding· reverse stepping, ~nd.possibly with further modif"ica.., _ tions.. The llri tish are using reversed stepping in their RM-26 

so this would give the British nothing they do not already· know. Thls is the only program which now appears satisfactory 

to the Navy •.. 

c. Make the SIGABA/CSP 8S9 available to the BI•i ti sh i~ event of emergency. It is·unacceptable to the Navy to give the ECM to the British at this time or.to coml?lit the United 

States to this action at some future date. 

d. Adopt the RM-26 - if, when, and as developed by· 

the B~itish. This will be unacceptable to the Navy for reasons 

of increased cost, lack ·of space aboard ship for a second 

machine, uncertain efI'1c1ency of the British me.chine, and pro- bable long delay in obtaining any workable production models. 

· e. Adopt the "radically different" ma.chine referred 

to j,.n reference (a). The Navy ca.nno"t agree for two reasons: 

(1) No Cryptog~aphic Aid for combined use can be 

accepted until thoroughly tested and in producticn, even ~f not i~ current use. 

(2} The Navy cannot foresee the elimination of 

Morse Code afloat and in the field and therefore cannot accept any cipher based on a 32-

character alphabet or requiring sole use of _te~etype apparatus. 

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5. The Army is again requested to accept CSP 2900 in 

principle, to undertake this conversion in connection With 

its own "rehabilitation program, .. and to agree on a target 

date for malc!ng CSP 2900 effective for Joint Commun:tcaticns. 11 · 

6. It ia believed that the B1 .. itish should be·-· given no 

further· 1nforir.a.t1on on these matters until fir•m Joint understar.dlng and agreement have been reached. ~ . ·' . . ·-..... ,... 

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