U.S. Naval Cryptologic Veterans Association

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Cryptology in History

These files relate to the history of cryptology in our nation’s history.

Traffic Analysis from Word War I through Vietnam
 2.25 MB

This brochure — prepared by the National Security Agency, Center for Cryptologic History — defines and explains traffic analysis when used in this context, as part of the broader discipline of signals intelligence. It describes the elements of traffic analysis and explains how traffic analysis has been used to produce intelligence information, to aid cryptanalysis, and to support the collection of additional data. It presents examples of intelligence contributions made by traffic analysis during World War I, World War II, and the Cold War through the Vietnam War.

Station CAST - Tip of the Lance
 374.09 KB

This article, authored by Timothy J. Mucklow and published online by the Society for History in the Federal Government, describes the politics and engineering behind the establishment of Station CAST on Corregidor Island — a project that began in 1934 with a proposal by then-LT Joseph Wenger and ended in 1940 when U.S. Navy cryptologic personnel began operations in the Navy Tunnel at Monkey Point.

This booklet, produced by the Center for Cryptologic History at the National Security Agency, describes the establishment and history of the U.S. Naval Reserve Security Group (U.S. Navy Security Group Reserve) from 1945 through 2005.

Journey to a Far Sea
 1.85 MB

This article, authored by CAPT William D. O’Neil (USNR) and published by the U.S. Naval Institute Proceedings in February 1982, describes the unclassified operation of a U.S. Navy ship, the USS FAIRFAX COUNTY (LST 1193), in the Barents Sea in the spring of 1981.

The National Security Agency and the EC-121 Shootdown
 20.47 MB

The National Security Agency and the EC-121 Shootdown is another addition to the NSA History and Publications Division's Special Crisis· Reports series. On 15 April 1969 a North Korean MIG-21 shot down a U.S. Navy EC-121 reconnaissance aircraft over the Sea of Japan. This is a study of the role NSA played in the crisis. It traces the origin and purposes of the flight, NSA's response to the shootdown, the aftermath investigations, and the resulting changes in the U.S. aerial reconnaissance program, warning procedures, and the development of the National Sigint Operations Center (NSOC).

Declassified and Approved for Release by NSA, CIA, DIA, the Joint Staff, NSC and OSD on 04-23-2013 pursuant to E.O 13526, MDR Case #60085