From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
The M-325 (SIGFOY) cipher machine was inspired by the German Enigma.

In the history of cryptography, M-325, also known as SIGFOY, was an American rotor machine designed by William F. Friedman in 1936. Between 1944 and 1946, more than 1,100 machines were deployed within the United States Foreign Service. Its use was discontinued in 1946 because of faults in operation. Friedman applied for a patent on the M-325 on 11 August 1944; it was granted on 17 March 1959 (US patent #2,877,565).

Like the Enigma, the M-325 contains three intermediate rotors and a reflecting rotor.

Friedman patented the design of the M-325 in US patent #2,877,565.

See also


  • Louis Kruh, Converter M-325(T), Cryptologia 1, 1977, pp143–149.

External links

  • Operating and Keying Instructions for Converter M-325(T) Headquarters, Army Security Agency, July 1948, scanned and transcribed by Bob Lord.
  • Friedman M-325 — information and photographs.
  • U.S. Patent 2,877,565
Retrieved from "https://en.wikipedia.org/w/index.php?title=M-325&oldid=846313532"
This content was retrieved from Wikipedia : http://en.wikipedia.org/wiki/M-325
This page is based on the copyrighted Wikipedia article "M-325"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA