- Frank Rowlett
Frank Byron Rowlett (
May 2 ,1908 -June 29 ,1998 ) was an Americancryptologist .He was born in
Rose Hill, Virginia and attended Emory & Henry College inEmory, Virginia , where he was a member of theBeta Lambda Zeta fraternity. In 1929 he received a bachelor's degree in mathematics and chemistry. He was hired byWilliam Friedman as a "junior cryptanalyst" for theSignals Intelligence Service (SIS) onApril Fool’s Day , 1930; shortly after, he was followed into SIS byAbraham Sinkov andSolomon Kullback .During the 1930s, after a lengthy period of training, Rowlett and his colleagues compiled codes and
cipher s for use by theU.S. Army and began solving a number of foreign, notably Japanese, systems. In the mid-1930s they solved the first Japanese machine forencipher ment of diplomatic communications, known to the Americans as RED. In 1939-40, Rowlett led the SIS effort that solved a more sophisticated Japanese diplomatic machine cipher, codenamedPURPLE by the U.S. Once, when asked what his greatest contribution to that effort had been, Rowlett said, "I was the one who believed it could be done."Rowlett also played a crucial role in protecting American communications during
World War II , making fundamental and innovative contributions to the design of theSIGABA cipher machine. Its security was an important factor in saving American lives in combat. (In 1964, Congress awarded Rowlett US$100,000 as partial compensation for his classified cryptologic inventions).In addition to having highly-developed cryptanalytic skills, Rowlett was a good manager, and he rose quickly within the organization. In 1943-1945 he was chief of the General Cryptanalytic Branch, and in 1945-1947 chief of the Intelligence Division. From 1949 to 1952, he was technical director in the Office of Operations of the
Armed Forces Security Agency , predecessor to theNational Security Agency (NSA).Rowlett differed with General
Ralph J. Canine , the first director of NSA, over personnel movements, including his own. Acting on his differences, he transferred to theCentral Intelligence Agency (CIA) in 1952 and worked there until 1958. At that time he returned toNSA as a Special Assistant to the Director. In 1965 Rowlett became commandant of theNational Cryptologic School . He retired from federal service in 1966. In 1965 he was awarded theNational Security Medal by PresidentLyndon B. Johnson for his work on breaking the Japanese Purple cipher.Rowlett has been inducted into the
Military Intelligence Hall of Fame .Because of his importance in the protection of American communications, the
Information Systems Security Organization has named its highest award theFrank Byron Rowlett Award .Frank Rowlett died June 29, 1998, at age 90.
References
* Frank B. Rowlett, "The Story of Magic: Memoirs of an American Cryptologic Pioneer", with Foreword and Epilogue by
David Kahn , Laguna Hills, CA, Aegean Press, 1999.
*James Gannon , "Stealing Secrets, Telling Lies: How Spies and Codebreakers Helped Shape the Twentieth century", Washington, D.C., Brassey's, 2001, especially chapter 6: Who Broke Purple? (pp. 94-106).
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