The code name for a decades-long, top-secret U.S. counterintelligence operation designed to break ciphered cable communications between Soviet intelligence outposts and their Moscow headquarters, especially during World War II and immediately afterwards. Launched in early 1943 by the U.S. Army’s Signal Intelligence newly renamed as U.S. Army Signals Security Agency, Venona would later prove to be the largest Western counterintelligence operation of the Cold War era, involving hundreds of cryptanalysts and linguists. Venona was officially terminated in 1980.

By the late 1940s, a team of U.S. cryptanalysts and linguists had managed to break the Soviet World War II-period cipher and to begin decrypting fragments of Soviet intelligence cable traffic. Joined in 1948 by the FBI, in 1949 by the British and later by the CIA, the effort finally resulted in partial decryption and translation of about 3,000 cables (out of a total of more than one million). These cables provided a glimpse into the activities of Soviet intelligence in the United States, including several hundred code names of agents, sources, contacts and targets of Soviet intelligence. Some of the code names were identified through U.S. counterintelligence efforts, but in some cases the identification, as well as the relationship of the person with Soviet intelligence, has remained uncertain.

Venona translations were finally made public in 1995-1996, and since then have become the basis for numerous books, articles and disputes.

Look for alerts on this website for further discussion of the readings of Venona decrypts.