Purple Dragon Study

September 1, 1966 - September 30, 1966

Overview

Beginning in September, the National Security Agency and other U.S. organizations investigate the ongoing problem of operational security in what subsequently becomes the Purple Dragon Study.

The apparent poor results of Arc Light and ROLLING THUNDER strikes prompt the investigation. The study examines all aspects of operations, from planning through execution, and determines that poor operational security has been giving the enemy advanced warning of coming strikes. Thereafter, security for the planning and execution of operations improves significantly. Purple Dragon concepts are ultimately used throughout the U.S. military and in other government agencies.¹

¹Unknown author, United States Cryptologic History, Series VI, The NSA Period, Volume 2: Purple Dragon: The Origin and Development of the United States OPSEC Program, Declassified Document (Washington, D.C.: Center for Cryptologic History, National Security Agency, 1993), 4, 7, 10–11, 22, 25, 62–63, 101 (http://www.nsa.gov/public_info/_files/cryptologic_quarterly/purple_dragon.pdf (link is external)); Thomas R. Johnson, United States Cryptologic History, Series VI, The NSA Period, 1952–Present, Volume 5: American Cryptology during the Cold War, Book II: Centralization Wins, 1960–1972 (Washington, D.C.: Center for Cryptologic History, National Security Agency, 1995), 551–553.