Search results
Results from the WOW.Com Content Network
Analog of the Japanese Type B Cipher Machine (codenamed Purple) built by the U.S. Army Signal Intelligence Service Purple analog equipment in use. 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 Office from February ...
The U.S. called this the "Purple" code, because they kept intercepted traffic in purple binders. Although the Japanese purchased the Enigma machine, they chose to base their cipher machine on a different technology, using a stepping switch rather than several rotors. [20]
PURPLE was an enticing, but quite tactically limited, window into Japanese planning and policy because of the peculiar nature of Japanese policy making prior to the War (see above). Early on, a better tactical window was the Japanese Fleet Code (an encoded cypher), called JN-25 by U.S. Navy cryptanalysts.
A cipher machine developed for Japanese naval attaché ciphers, similar to JADE. It was not used extensively, [5] [6] but Vice Admiral Katsuo Abe, a Japanese representative to the Axis Tripartite Military Commission, passed considerable information about German deployments in CORAL, intelligence "essential for Allied military decision making in the European Theater."
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.
Leo Rosen (26 March 1916 – 16 March 1991) was an American cryptanalyst who worked with Frank Rowlett at Signals Intelligence Service (S.I.S.) before the start of World War II on Japanese ciphers. Rowlett found a method to read the messages enciphered on the Japanese PURPLE machine.
The Japanese army was aware of machine systems; at the Hague in 1926, a Japanese military attaché saw a demonstration of the Model B1 cipher machine from Aktiebolaget Cryptograph. [34] In fact, in the early 1930s, both the Japanese Navy and the Foreign Ministry switched to machine systems for their most secret messages.
Japanese Navy ORANGE cryptographic device captured by US Navy. In the history of cryptography, 91-shiki ōbun injiki (九一式欧文印字機, "System 91 Typewriter for European Characters") or Angōki Taipu-A (暗号機 タイプA, "Type A Cipher Machine"), codenamed Red by the United States, was a diplomatic cryptographic machine used by the Japanese Foreign Office before and during World ...