war, most of the SIS staff, some 7,000 out of a total 10,500, were female. Ann Z. Caracristi, who would later become Deputy Director of the National Security Agency, started her career there and was a prolific breaker of Japanese army codes. The unit she worked in, largely staffed and led by women, produced a flow of intercepts from the "2468" shipping code system that resulted in the sinking of two-thirds of the Japanese merchant marine. Midway through World War II, in 1943, the Army Signal Intelligence Service (later the Army Security Agency) began intercepting Soviet (Russian) intelligence traffic sent mainly from New York City; they assigned the code name "Venona" to the project. Although the United States had become allies with the Soviet Union in 1941, many officials were suspicious of the communist government and society. By 1945, some 200,000 messages had been transcribed, a measure of Soviet activity. On 20 December 1946, after the war and at a time of increasing US tensions with the Soviet Union, Meredith Gardner made the first break into the Venona code. Decrypted messages revealed the existence of Soviet espionage at the Los Alamos National Laboratory work on the top-secret Manhattan Project, where the atomic bomb had been developed and research continued. The Venona project was so highly classified, however, that the government never introduced evidence from these messages into court proceedings in prosecution of alleged espionage agents. Intercept network The Army intercept network during WWII had six fixed stations, which concentrated on Japanese military signals and Axis diplomatic traffic. Vint Hill Farms Station, Warrenton, Virginia Two Rock Ranch, Petaluma, California Fort Shafter, Territory of Hawaii Fairbanks, Alaska New Delhi, India Asmara, Eritrea See also Signals intelligence OP-20-G United States Coast Guard Unit 387 National Defence Radio Establishment References External links Pearl Harbor Review. Signal Intelligence Service, National Security Agency/Central Security Service. Nsa.gov. Bernard A. Weisberger "Eavesdropping on the Rising Sun", American Heritage magazine. Budiansky, Stephen, Battle of Wits: The Complete Story of Codebreaking in World War II, Free Press, 2000. стр.357 . William F. Friedman, "A Brief History of the Signal Intelligence Service," 29 June 1942, SRH 029, CCH Files. Anon. "Centralized Control of U.S. Army Signal Intelligence Activities," SRH-276, CCH Files. Anon., "Memorandum" re O.C.S.O Conference, 19 July 1929. Anon., "The Second Signal Service Battalion," SRH-135, CCH Files. U.S. Army Signals intelligence in World War II. A documentary history. Edited by