VENONA project

From Academic Kids

The VENONA project was a long-running and highly secret collaboration between the United States intelligence agencies and the United Kingdom's MI5 that involved the cryptanalysis of Soviet messages.



U.S. Army Signal Security Agency (commonly called Arlington Hall) codebreakers had intercepted large volumes of encrypted high-level Soviet diplomatic and intelligence traffic during and immediately after World War II. The British had stopped intercepting Soviet traffic, at Winston Churchill's orders, shortly after Germany invaded the Soviet Union in 1941 and had no traffic to contribute to the project after that time. This traffic, some of which was thought to be encrypted with a one-time pad system, was stored and analyzed in relative secrecy by hundreds of cryptanalysts over a 40-year period starting in the early 1940s. The National Security Agency reported that, according to the serial numbers of the Venona cables, thousands were sent but only a fraction were available to the cryptanalysts. Approximately 2,200 of the messages were decrypted and translated; some 50 percent of the 1943 GRU-Naval Washington to Moscow messages were broken, but none for any other year, although several thousand were sent between 1941 and 1945. The decryption rate of the KGB cables was:

  • 1942 1.8%
  • 1943 15.0%
  • 1944 49.0%
  • 1945 1.5%

The Venona Project actually initiated when the Chief of Military Intelligence, Carter Clarke, did not trust Joseph Stalin. He feared that Stalin and Hitler would sign a peace treaty in order to focus the Nazi's militaristic forces on the destruction of Great Britain and the U.S.

The British codename for VENONA was Bride. Some brilliant cryptanalysis by American and British codebreakers (the first steps were by a very young Meredith Gardner of what would become NSA) revealed that some of the one-time pad key material had incorrectly been reused by the Soviets, which allowed decryption (sometimes only partial) of a small part of the traffic. Very slowly, using assorted techniques ranging from traffic analysis to defector information, more of the messages were decrypted. Out of some hundreds of thousands of intercepted cyphertexts, it is claimed that under 3000 have been partially or wholly decrypted. Claims have made that information from physical theft of encryption pads (a partially burned one is reported to have been recovered by the Finns) to bugging embassy rooms in which text was entered into encrypting devices (and analyzing the keystrokes by listening to them being punched in), contributed to achieving as much plaintext as was recovered. These latter claims are less than fully supported in the open literature.

This decryption and cryptanalysis project became known to the Soviets not long after the first breaks. It is not clear whether the Soviets knew how much of the message traffic, or which messages, had been successfully decrypted. At least one Soviet agent, Kim Philby, was told about the project as part of his job as liaison between British and US intelligence. The project continued for decades, long after Philby left British intelligence.

The decrypted messages from Soviet aid missions, GRU spies, KGB spies, and some diplomatic traffic, known collectively as the VENONA papers, gave important insights into Soviet behavior in the period during which duplicate one-time pads were used. They also revealed the existence (and in some case implied the identities) of some American, Canadian, Australian, and British Soviet spies in research and in government, including Klaus Fuchs, Julius and Ethel Rosenberg, and at least one of the Cambridge Five spy ring (Donald Maclean).

The Soviets eventually stopped reusing key pad material, possibly after learning from their agent(s) of the US / British work, after which their one-time pad traffic reverted to completely unreadable. There has been speculation that the reason for the key material duplication was the increase in work (including key pad generation) in the period after the German attack in June of 1941. Other suggestions have it that it was Guderian's tanks just outside Moscow in early December that year which forced Moscow Centre to make such a fundamental error.


The VENONA documents, and the extent of their significance, were not made public until 1995. They show that the US and others were targeted in major espionage campaigns by the Soviet Union as early as 1942. The Office of Strategic Services, the predecessor to the CIA, housed at one point or another between fifteen and twenty Soviet spies. The War Production Board, the Board of Economic Warfare, the Office of the Coordinator of Inter-American Affairs and the Office of War Information, included at least half a dozen Soviet sources each among their employees.

The decision to keep Venona secret and restrict knowledge of it within the government was made by senior Army officers in consultation with the FBI and CIA. The CIA was not made an active partner until 1952. It appears Army Chief of Staff Omar Bradley, concerned about the White House's history of leaking sensitive information, decided to deny President Truman direct knowledge of the project. The president recieved the substance of the material only through FBI, Justice Department and CIA reports on counterintelligence and intelligence matters. He was not told the material came from decoded Soviet ciphers. Truman had been distrustful of J. Edgar Hoover, head of the FBI, and suspected the reports were exaggerated for political purposes.

The decrypts include code names for 349 individuals who were maintaining a covert relationship with the Soviet Union. It can be safely assumed that more than 349 agents were active, as that number is from a small sample of the total intercepted message traffic. Among those thought to be identified are Alger Hiss, believed to have been the agent "ALES"; Harry Dexter White, the second-highest official in the Treasury Department; Lauchlin Currie, a personal aide to Franklin Roosevelt; and Maurice Halperin, a section head in the Office of Strategic Services. Almost every military and diplomatic agency of any importance was compromised to some extent, including the Manhattan Project. Even today, the identities of fewer than half of the 349 agents are known with any certainty. Agents who were never identified include "Mole", a senior Washington official who passed information on American diplomatic policy, and "Quantum", a scientist on the Manhattan Project.

Some known spies, including Theodore Hall, were neither prosecuted nor publicly implicated, because the VENONA evidence against them could not be made public. VENONA evidence has also clarified the case of Ethel and Julius Rosenberg, making it clear that Julius was guilty of espionage while Ethel was guilty of cooperating, while also showing that their contributions to Soviet nuclear espionage were less important than was publicly alleged at the time. In fact, Ethel had been only an accomplice, and Julius' information was probably not as valuable as that provided by sources like "Quantum" and "Pers" (both still unidentified.)

This is an extremely different picture from the one which had developed over most of 50 years in the absence of solid evidence. While critics debate the identity of individual agents, the overall picture of infiltration is more difficult to refute. The release of the VENONA information has forced reevaluation of the Red Scare in the US.

In Australia, the founding of the Australian Security Intelligence Organisation by Labor Prime Minister Ben Chifley was considered highly controversial within Chifley's own party. Until then, the left-leaning Australian Labor Party had been hostile to domestic intelligence agencies on civil liberties grounds, and a Labor government actually founding one was a surprising about face. VENONA material has now made it clear that Chifley was motivated by evidence that not only were there a large number of very damaging Soviet agents operating in Australia, but that these probably included members of his party. Chifley was succeeded by the conservative, zealously anti-communist Sir Robert Menzies. Menzies began what was long considered an over-zealous anti-communist "witch hunt", but it is now known that VENONA decrypts and associated surveillance had identified one of the Soviet agents as being either the popular "Doc" Evatt (one of Chifley's Cabinet Ministers, instrumental in the early organisation of the United Nations, and former President of the UN General Assembly), or Evatt's secretary Alan Dalziel. As well, other middle ranking government officials were either identified or implicated. Further, investigation had revealed that Wally Clayton (codenamed KLOD), a Soviet agent within the Communist Party of Australia, was forming an illegal "underground network" within the CPA, presumably as a prelude to political violence. When Menzies announced a Royal Commission into Soviet espionage in Australia, it was supported by the anti-communist Roman Catholic factions of the ALP but strongly opposed by "Doc" Evatt and allies. The ALP eventually split over this issue.

List of Americans in Venona Papers

349 U.S. citizens, noncitizen immigrants, and permanent residents of the United States who had covert relationships with Soviet intelligence were confirmed in the Venona traffic. Of these 171 are identified by true names and 178 are known only by a cover name. The persons identified represent only a partial list and many are listed below. Twenty-one persons targeted for recruitment remain uncorroborated as to it being accomplished. These individuals are marked with an asterisk (*). The NSA followed Soviet intelligence traffic for only a few years in World War II and decrypted only a small portion of that traffic. The evidence of a covert relationship of another 139 persons from sources other than Venona decryptions has been documented and many can be found within the list of Category:Soviet spies.


Critics of VENONA point out that the intelligence agencies did not have actual names for any of the Soviet agents mentioned, so their identity had to be inferred, often using other information sources. Alger Hisss known cryptonyms were "Lawyer" ("Advocate" or "Advokat") in the mid-1930s and "Ales" in 1945. The critics argue that with the lack of actual names (eg, ALES is assumed to be Hiss, one reason being that he was at Yalta[1] (, all VENONA really shows is that there were numerous Soviet agents in the United States. In response, it has been noted that iron-clad proof is rare in espionage cases, and in fact in many ordinary criminal cases.

Document Release Issues

The NSA has failed to release the VENONA documents as a Unicode based PDF text file. Text processing technology could be used to extract information from the decrypts for historical research if the VENONA documents were released in PDF form.

The NSA website states: "These historical documents are GIF images of formerly classified carbon paper and reports that have been declassified. Due to the age and poor quality of some of the GIF images, a screen reader may not be able to process the images into word documents."

[...] "individuals may request that the government provide auxiliary aids or services to ensure effective communication of the substance of the documents. For such requests, please contact the Public Affairs Office at 301-688-6524."

See Also


  • The Hidden Hand: Britain, America, and Cold War Secret Intelligence; by Richard J. Aldrich. New York: Overlook Press, 2002. ISBN 1585672742.
  • Body of Secrets: Anatomy of the Ultra-Secret National Security Agency; by James Bamford. Anchor Books. ISBN 0385499086. See also the same author's earlier, The Puzzle Palace, also about the NSA.
  • Bombshell; by Albright and Kunstel. About Soviet WWII espionage in the US, including Venona.
  • Battle of Wits; by Steven Budiansky. An overview in one volume of cryptography in WWII.
  • NSA official VENONA site (
  • VENONA; Decoding Soviet Espionage in America, Yale University Press. Despite the title, this is less about VENONA itself than about Communist Party USA espionage and support of espionage. It is based on research in the CPUSA archives made available to the authors in Moscow. See YUP Web site information on the book (
  • Robert L. Benson, The Venona Story, pamphlet (Ft. Meade, MD: Center for Cryptologic History, National Security Agency, 2001)
  • Robert Louis Benson, The KGB and GRU in Europe, South America, and Australia: Venona Historical Monograph #5, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Cryptologic History, 1998)
  • Robert Louis Benson, The KGB in San Francisco and Mexico City: The GRU in New York and Washington: Venona Historical Monograph #4, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Cryptologic History, n.d.)
  • Robert Louis Benson, The 194445 New York and Washington-Moscow KGB Messages: Venona Historical Monograph #3, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Cryptologic History, n.d.)
  • Robert Louis Benson, The 194243 New York-Moscow KGB Messages: Venona Historical Monograph #2:, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Cryptologic History, n.d.)
  • Robert Louis Benson, Venona: New Releases, Special Reports, and Project Shutdown: Venona Historical Monograph #6, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Crytologic History, n.d.)
  • Robert Louis Benson, Introductory History of Venona and Guide to Translations, pamphlet, Venona Historical Monograph (Fort Meade, Maryland: Center for Cryptologic History, n.d.)
  • Selected Venona Messages (
  • venona-mirror.html (
  • MI5 Releases to the National Archives (
  • Cover Name, Cryptonym, CPUSA Party Name, Pseudonym, and Real Name Index (
  • Venona FBI FOIA Files (ベノナ

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