William F. Friedman
William F. Friedman | |
|---|---|
| Born | Wolf Friedman September 24, 1891 |
| Died | November 2, 1969 (aged 78) Washington, D.C., United States |
| Nationality | Romanian, Russian, American |
| Spouse | Elizebeth Smith Friedman |
| Children | 2 |
| Engineering career | |
| Significant advance | cryptologist |
William Frederick Friedman (September 24, 1891 – November 2, 1969) was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett broke Japan's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II.