Cryptologic Quarterly NSA’s Friedman Conference Center PLUS: Vint Hill Farms Station • STONEHOUSE of East Africa The Evolution of Signals Security • Mysteries of Linguistics 2019-01 • Vol. 38 Center for Cryptologic History Cryptologic Quarterly Contacts. Please feel free to address questions or comments to Editor, CQ, at
[email protected]. Disclaimer. All opinions expressed in Cryptologic PUBLISHER: Center for Cryptologic History Quarterly are those of the authors. Th ey do not neces- CHIEF: John A. Tokar sarily refl ect the offi cial views of the National Security EXECUTIVE EDITOR: Pamela F. Murray Agency/Central Security Service. MANAGING EDITOR: Laura Redcay Copies of Cryptologic Quarterly can be obtained by ASSOCIATE EDITOR: Jennie Reinhardt sending an email to
[email protected]. Editorial Policy. Cryptologic Quarterly is the pro- fessional journal for the National Security Agency/ Central Security Service. Its mission is to advance knowledge of all aspects of cryptology by serving as a forum for issues related to cryptologic theory, doc- trine, operations, management, and history. Th e pri- mary audience for Cryptologic Quarterly is NSA/CSS professionals, but CQ is also distributed to personnel in other United States intelligence organizations as well as cleared personnel in other federal agencies and departments. Cryptologic Quarterly is published by the Center for Cryptologic History, NSA/CSS. Th e publication is de- signed as a working aid and is not subject to receipt, control, or accountability. Cover: “Father of American cryptology” William Friedman’s retirement ceremony in the Arlington Hall Post Theater, Arlington, VA, 1955. Lieutenant General Ralph Canine is at left, Solomon Kullback is seated left, Friedman is second from right, and Director of Central Intelligence Allen Dulles is at far right.