VENONA Project

The decrypts of Soviet intelligence cables that confirmed atomic espionage, secret until 1995

Overview

VENONA began in 1943 when analysts detected reused key material in Soviet diplomatic cables encrypted with one time pads that had been misused. Over decades, cryptanalysts including Meredith Gardner decrypted thousands of messages from the 1940s, matching covernames to real people and confirming atomic espionage by the network around Julius Rosenberg and by Theodore Hall. The program stayed secret until 1995 because its fragmentary products could not be used in court. Its release transformed the historical understanding of Soviet espionage in America.