William F. Friedman

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "William F. Friedman" – news · newspapers · books · scholar · JSTOR (January 2013) (Learn how and when to remove this message)

William F. Friedman
Born	Wolf Friedman September 24, 1891 Chișinău, Kishinyovsky Uyezd, Bessarabia Governorate, Russian Empire
Died	November 12, 1969(1969-11-12) (aged 78) Washington, D.C., United States
Nationality	Romanian, Russian, American
Occupation	Engineer
Spouse	Elizebeth Smith Friedman
Children	2
Engineering career
Significant advance	cryptologist

William Frederick Friedman (September 24, 1891 – November 12, 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.