American Cryptology during the Cold War - The Black Vault

Kim Philby strikes a smug pose during a 1955 press conference
after a British investigation failed to definitely finger him as a Soviet agent.
All the readable VENONA messages which supplied information about U.S. spies were
transmitted by 1946 or earlier. Most of the decrypted traffic came from ASA's 1944-45
files and was not decrypted until the late 1940s and early 1950s. But exploitation efforts
continued for years and were not finally closed down until 1980. By then, the traffic being
worked was thirty-five years old. The reason for this long delay was simple. VENONA
translations were incredibly difficult, each one requiring approximately one man-year of
work.
The VENONA material played a key, although by no means exclusive, role in catching
the atomic spies and the Philby ring. Most of the evidence came from meticulous
counterintelligence work by the FBI, not from COMINT. VENONA frequently confirmed
what the FBI had suspected, but it never had to be used in court. All the prosecutions
stood solely on evidence gained from other sources. What, then, was its historical
importance?
First, VENONA provided the prod. Early VENONA decrypts revealed the scope and
direction of KGB operations. It confirmed that fragmentary information provided by
people like Krivitsky and Gouzenko, and public allegations by Elizabeth Bentley and
Whittaker Chambers, was precisely on target and had to be pursued. With VENONA in
hand, Lamphere got his marching orders.
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