Type A Cipher Machine
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 War II. A relatively simple device, it was quickly broken by western cryptographers. The Red cipher was succeeded by the Type B "Purple" machine (九七式印字機, 97-shiki ōbun injiki; "System 97 Typewriter for European Characters") which used some of the same principles.