Date invented | 1944 [1] |
---|---|
Type | rotor machine |
In the history of cryptography, M-325, also known as SIGFOY, [2] was an American rotor machine designed by William F. Friedman and built in 1944. [3] 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; [4] it was and 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.