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Resume of Work of the Code and Cipher Section 

1. 

printed. 

Division Field Code No. 7 - prepared'in ms., proofread, 

2. New code - nThe General Address and Signature Code" was 

prepared, mim&ographed, and distributed. To be used in abbreviating 

all addresses and signatures of radio mes~ages handled b;y radio 

stations of the Army and certain stations of the Navy. Its use 

will facilitate traffic. Effective 1 November. 

3. Array Field Code: vocabulary and code groups prepared. 

Ms. in preparation tor printing. 11It w5J.l be a code approximately 

three times the size of the Division Field Codes" - to i:>e used for 

tactical field messages between units fro~ DiviEion upward. 

4. Tra.ir..ing Pamphlet 163 - Elements of Cryptanalysis written 

and 11ow in press. To be standard text. for instruction of signal 

offic:ers in code and cipher work. Mr. Fried.'Il8Il at tr.at time ~ave 

a two week course annually at the Signal School, Camp Vail. 

5. Special code for airplane communication with gro-;mc stations 

in fire control and general reconnaissance work prepared. Being 

tested by units of VIII Co~ps hrea, Hawaiian and Philippine Depts. 

6. General method of solving so-called "Double Transposition 

Ciphern, heretofore considered by all experts to be indecipherhble, 

was devised and tested. 15 messages in as rr.any different keys were 

solved. 

7. B!" direction of Joint Board, 89> cipher for secret com- - munic:ation between Anny and Navy was to be prepared. New cipher 

devi1sed by 7:. F. Friedman approved by Viar and ?~avy Dept. "It reauires 

only pencil and paper and is considered to be absolutely indecipherable 

without a knowledge of the kej word, even though all the details 

of oreratine the cipher may be knovm to the ene~." 

8. Many cipher systems and several cipher machines submitted 

by i11ventors examined and all rejected since they did not maet reaui~ements regarding practicability and secrecy flan extremely 

ingenious electrical cipher machine is now being studied jointly 

with the Code and Signal Section " of l?avy. Friedman directing 

investigation and Navy providing personnel. for detailed work such 

as preparation of messages, tables, etc. "The results of my studies 

Declassified and approved for release by NSA on 07-29-2014 pursuantto E.O. 1352a 

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so far. seem to indicate that the messages produced by th~ machine · are 11ot nearly as secure es formerly believed by the Navy Department. n -· . ::"": .. 

9. Stud.7 of telegraph alphagets in connection with Gen. 

Squier 1 s new method of transrr..ittine the alphabet. Aim to see 

whether certain funda.:!lental changes i.ri symbols will bring telegraph 

alphabet more in harmoey with the renu~ents and results of modern ,.. traf:!."ic experience. 

10. "Some time has been devoted to the general problem of 

speeding up the methods of secret co.m.'l'D.lnicAtion by the use of 

telegraph machines to which cipher devices may be applied. This 

is the co.ming development in cryptography". 

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