Vietnam War National Security Agency (NSA) Official History Volumes Cryptologic Historical Series

Vietnam War National Security Agency (NSA) Official History Volumes Cryptologic Historical Series

980 pages of official National Security Agency histories covering NSA activities in Southeast Asia, during the Vietnam War

These histories were published from 1969 to 1993. Some material released remained top secret until 2007. Much is still considered by the NSA to be too sensitive to be released, and remains classified. The Cryptologic Historical Series began as a result of a proposal, made to Marshall S. Carter, Lieutenant General, U.S. Army, Director, NSA, in the spring of 1967 by Major General Charles J. Denholm, CGUSASA, that a NSA-SCA team be formed to prepare a complete, historical documentation of SIG INT operations in support of U.S. military operations in Southeast Asia.

The four volumes on this collection include:

Southeast Asia: In the Shadow of War (To the Gulf of Tonkin)

159 page, June 1969 NSA history that remained completely classified as Top Secret until 2004. The publication of this volume marked the inauguration of the NSA's Cryptologic Historical series covering the Vietnam War. Subject matter covered include: The political history of the conflict in Southeast Asia and the developing role of the NSA. History of the establishment of the SABERTOOTH program, under which the United States provided training for South Vietnamese Army personnel in interception, direction finding, and the processing of communications. Also covered, the expansion of NSA personnel and equipment in Vietnam from 1961 to 1965.

Approximately 65 percent of the information in this publication remains classified secret and was redacted by the NSA.


Southeast Asia: Working Against the Tide (COMSEC Monitoring and Analysis)

A 193 page, June 1970 report on Communications Security (COMSEC) in Southeast Asia during the Vietnam War.

Approximately 40 percent of the information in this publication remains classified secret and is redacted by the NSA.

"Working Against the Tide" is the story of the attempts of U.S. COMSEC monitors and analysts to bring security to the voluminous communications during the Vietnam War. It outlines the problems confronting COMSEC specialists in dealing with communication-prone Americans at all levels of command. It gives insight into and documentation for the damage done to the United States and its allies as the opposition's SIGINT organization capitalized on American laxity in communications security. The story describes the technology applied in Southeast Asia to overcome COMSEC deficiencies and the manner in which that technology evolved during the war, particularly as monitoring adapted to a new methodology termed COMSEC surveillance. It further tells of U.S. attempts to apply monitoring knowledge in communications cover and deception operations against the opposition.

The authors of "Working Against the Tide" drew upon a wide variety of source materials in presenting their composite picture of monitoring and analysis in Southeast Asia. While the major part of these sources was for the years to 1968, the authors also used source documents from the 1968 and 1969 period, when the materials were particularly germane to the topics under discussion. Important source materials included SCA monitoring reports, operational messages, reports issued by the military commands, briefings, special studies, SIGINT, and author interviews with commanders. One primary source of information was the SCA historical publications. The authors drew upon accounts provided by unit historians of components of the 509th ASA Group and the 6922d AFSS Security Wing. From these, the authors extracted sufficient information to treat in brief form the operations conducted by ASA and AFSS COMSEC units.


PURPLE DRAGON: The Origin and Development of the United States OPSEC Program

A 106 page, June 1993 NSA history that remained completely classified as Top Secret until December 2007. This monograph covers the NSA's involvement in the establishment of Operational Security in Southeast Asia during the Vietnam War.

The intelligence analyst author of this monograph, whose name remains classified by the NSA, gives an account that describes the initial problems in air operations which prompted a high-level investigation. The author explains the weaknesses in U.S. practices which this investigation identified, shows how operations security principles were developed through close analysis of the problems and weaknesses, and, finally, tells how operations security at last became institutionalized.

According to the author, in its involvement in Vietnam, the U.S. military came to the realization that several of its operations, such as ARC LIGHT and ROLLING THUNDER, were not being fully successful. Enemy forces were somehow consistently able to avoid the full blow of U.S. and Allied operations.  Assuming that North Vietnam and the Viet Cong were not likely to be decrypting the United States' most secure communications and that they could not have enough spies in South Vietnam to be aware of every U.S. operation in Southeast Asia before they took place, U.S. personnel came to the conclusion that U.S. forces were themselves inadvertently revealing vital information to the opposition.

To test this hypothesis, the U.S. Joint Chiefs of Staff authorized Operation PURPLE DRAGON. Relying on a multidisciplinary investigation of all aspects of combat operations, from conception to planning to execution, PURPLE DRAGON sought to uncover those elements of an operation which might be insecure and which of those elements might be able to provide valuable, exploitable information to the opposition.

Report sections include: The Beginnings of OPSEC, PURPLE DRAGON at War, NSA and PURPLE DRAGON, What Charlie Knew, OPSEC Goes Worldwide, and PURPLE DRAGON at Peace.

Approximately 65 percent of the information in this publication remains classified secret and was redacted by the NSA.


Spartans in Darkness: American SIGINT and the Indochina War, 1945-1975

A 522 page, year 2002 monograph by Robert Hanyok, which was completely classified as Top Secret until December 2007.

According to David A. Hatch, Director, Center for Cryptologic History, "The Vietnam War has been the subject of countless memoirs, histories, and adventure tales, yet a critical aspect of the war has been lacking in what has been written so far. Even monographs on the roll of intelligence in the war do not treat the signals intelligence (SIGNIT) and information systems security (INFOSEC) aspects of the war, or do so only in the most superficial ways. Robert Hanyok's meticulously researched and richly detailed history of cryptology in the Vietnam War fills this void. It provides a grand perspective of these most secret aspects of the war, and answers many of the questions historians ask about it.  This monograph contains an in-depth and mostly un-redacted look at the NSA's view of the Gulf of Tonkin Incident."
 
Approximately 40 percent of the information in this publication remains classified secret and was redacted by the NSA.

Chapter titles include:

The Early COMINT Effort against Viet Minh Communications

The Struggle for Heaven's Mandate: SIGINT and the Internal Crisis in South Vietnam

To Die in the South: SIGINT, the Ho Chi Minh Trail, and the Infiltration Problem

The Burden's First Fanfare: American SIGINT Arrives in the Republic of Vietnam, 1961-1964

Second Interlude: The Center Does Not Hold: Post-Diem South Vietnam, 1964

Skunks, Bogies, Silent Hounds, and the Flying Fish: The Gulf of Tonkin Mystery, 2-4 August 1964

Xerxes' Arrows: SIGINT Support to the Air War, 1964-1972

Third Interlude: "Who'll Stop the Rain?" America Enters the Ground War, 1965-1967

A Springtime of Trumpets: SIGINT and the Tet Offensive

Fourth Interlude: Grasping at the Straws of Victory, 1968-1970

In Our Own Image: NSA, Vietnamizatlon, and the Expansion of South Vietnamese SIGINT, 1969-1973

The Last Ramparts of Our Conceits: The DGTS, American SIGINT, and the Fall of South Vietnam, 1973-1975

The Still, Small Voice: Aftermath and Conclusions, 1975 and Beyond



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