Editing Venona project (section)

===Results===
The NSA reported that (according to the serial numbers of the Venona cables) thousands of cables were sent, but only a fraction were available to the cryptanalysts. Approximately 2,200 messages were decrypted and translated; about half 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 NKVD cables was as follows:
* 1942: 1.8%
* 1943: 15.0%
* 1944: 49.0%
* 1945: 1.5%

Out of some hundreds of thousands of intercepted encrypted texts, it is claimed under 3,000 have been partially or wholly decrypted. All the duplicate one-time pad pages were produced in 1942, and almost all of them had been used by the end of 1945, with a few being used as late as 1948. After this, Soviet message traffic reverted to being completely unreadable.<ref>
{{cite book
|author1=Haynes, John Earl |author2=Klehr, Harvey
|name-list-style=amp |year = 2000
| title = Venona: Decoding Soviet Espionage in America
| publisher = Yale University Press
| page = 55
| isbn = 978-0-300-08462-7
}}</ref>

The existence of Venona decryption became known to the Soviets within a few years of the first breaks.<ref name="osti.gov">{{Cite web |title=Manhattan Project: The Venona Intercepts |url=https://www.osti.gov/opennet/manhattan-project-history/Events/1945-present/venona.htm |access-date=2023-10-10 |website=www.osti.gov}}</ref> 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 penetration agent, British [[Secret Intelligence Service]] representative to the US [[Kim Philby]], was told about the project in 1949, as part of his job as liaison between British and US intelligence.<ref name="osti.gov"/> Since all of the duplicate one-time pad pages had been used by this time, the Soviets apparently did not make any changes to their cryptographic procedures after they learned of Venona. However, this information allowed them to alert those of their agents who might be at risk of exposure due to the decryption.