The U.S. Army's Signal Intelligence Service, the precursor to the National Security Agency, began a secret program in February 1943 later codenamed VENONA

The mission of this small program was to examine and exploit Soviet diplomatic communications but after the program began, the message traffic included espionage efforts as well.

Although it took almost two years before American cryptologists were able to break the KGB encryption, the information gained through these transactions provided U.S. leadership insight into Soviet intentions and treasonous activities of government employees until the program was canceled in 1980.

The VENONA files are most famous for exposing Julius (code named LIBERAL) and Ethel Rosenberg and help give indisputable evidence of their involvement with the Soviet spy ring.

The first of six public releases of translated VENONA messages was made in July 1995 and included 49 messages about the Soviets' efforts to gain information on the U.S. atomic bomb research and the Manhattan Project. Over the course of five more releases, all of the approximately 3,000 VENONA translations were made public.

 8MAY_CIPHER_FOR_FELIX.PDFCipher for "FELIX" to be modelled on that used by "ALBIN" 8 May 1942 (Release 5)
 13JUL_CIPHER.PDFCipher matters 13 July 1943 (Release 4)
 19MAR_CIPHER.PDFCipher matters 19 March 1943 (Release 4)
 27APR_CIPHER.PDFCipher matters 27 April 1943 (Release 4)
 30JUL_CIPHER_MATTERS.PDFCipher matters 30 July 1943 (Release 4)
 18JAN_CIPHER_PROBLEMS.PDFCipher problems.
 13OCT_CIPHERS_ALBIN_MODEL.PDFCiphers for two agents to be modelled on that used by "ALBIN"
 25APR_CIPHER.PDFCircular to all residents on cipher matters
 10APR_COMMS_PROCEDURES.PDFCircular to all residents on communications procedures 10 April (Release 5)
 6NOV_CLAUDE_WARNED.PDFCLAUDE to be warned concerning contact with Moore 6 November (Release 5)
 9JAN_MARKIN.PDFClearing MARKIN's wife 9 January 1943 (Release 5)
 10MAY_CODE_CIPHER.PDFCode and cipher matters. Mention of cipher pads used for communication with Soviet submarines. 10 May 1943 (Release 4)
 16MAR_CODEBOOK.PDFCodebook changes 16 March 1943 (Release 4)
 21JUN_CODES_AVIATION_WORKERS.PDFCodes and aviation workers 21 June (Release 3)
 29JAN_FUNDS.PDFCollection of funds 29 January 1943 (Release 4)
Page 39 of 100