Search results
Results from the WOW.Com Content Network
A copy of the code book was obtained in a "black bag" operation on the luggage of a Japanese naval attaché in 1923; after three years of work Agnes Driscoll was able to break the additive portion of the code. [2] [3] [4] Knowledge of the Red Book code helped crack the similarly constructed Blue Book code. [1]
For eighteen months, she worked with other SIS codebreakers to analyze the encryption system used in the Japanese Type B Cipher Machine, code named Purple by the SIS [3]: p. 8 She played a key role in cracking the cipher, [4] discovering cyclical behavior in the code on September 20, 1940.
The Emperor's Codes: Bletchley Park and the breaking of Japan's secret ciphers. London: Bantam Press. ISBN 0593-046412. Smith, Michael and Erskine, Ralph (editors): Action this Day (2001, Bantam London; pages 127-151) ISBN 0-593-04910-1 (Chapter 8: An Undervalued Effort: how the British broke Japan’s Codes by Michael Smith)
In the lead-up to the U.S. declaring war on Japan and eventually Germany, American intelligence had cracked Japan's diplomatic codes.
Herbert Osborn Yardley (April 13, 1889 – August 7, 1958) was an American cryptologist.He founded and led the cryptographic organization the Black Chamber.Under Yardley, the cryptanalysts of The American Black Chamber broke Japanese diplomatic codes and were able to furnish American negotiators with significant information during the Washington Naval Conference of 1921–1922.
Analog of the Japanese Type B Cipher Machine (codenamed Purple) built by the U.S. Army Signal Intelligence Service Purple analog in use. In the history of cryptography, the "System 97 Typewriter for European Characters" (九七式欧文印字機 kyūnana-shiki ōbun injiki) or "Type B Cipher Machine", codenamed Purple by the United States, was an encryption machine used by the Japanese Foreign ...
Early on, a better tactical window was the Japanese Fleet Code (an encoded cypher), called JN-25 by U.S. Navy cryptanalysts. Breaking into the version in use in the months after December 7, 1941 provided enough information to lead to U.S. naval victories in the battles of the Coral Sea and Midway , stopping the initial Japanese advances to the ...
The Man Who Broke Purple: the Life of Colonel William F. Friedman, Who Deciphered the Japanese Code in World War II. Boston: Little Brown & Co. ISBN 978-0316145954. OCLC 3072401. Friedman, William F. (1984). Six Lectures on Cryptology. U.S. National Security Agency, 1965, declassified 1977. Gannon, James (2001).