The Venona project was a United States counterintelligence program initiated during World War II by the United States Army's Signal Intelligence Service, which ran from February 1, 1943, until October 1, 1980. It was intended to decrypt messages transmitted by the intelligence agencies of the Soviet Union. Initiated when the Soviet Union was an ally of the US, the program continued during the Cold War, when the Soviet Union was considered an enemy.
William Frederick Friedman was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett broke Japan's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II.
Arlington Hall is a historic building in Arlington, Virginia, originally a girls' school and later the headquarters of the United States Army's Signal Intelligence Service (SIS) cryptography effort during World War II. The site presently houses the George P. Shultz National Foreign Affairs Training Center, and the Army National Guard's Herbert R. Temple, Jr. Readiness Center. It is located on Arlington Boulevard between S. Glebe Road and S. George Mason Drive.
Herbert Osborn Yardley was an American cryptologist. He founded and led the cryptographic organization the Black Chamber. Under Yardley, the cryptanalysts of The American Black Chamber broke Japanese diplomatic codes and were able to furnish American negotiators with significant information during the Washington Naval Conference of 1921–1922. Recipient of the Distinguished Service Medal. He wrote The American Black Chamber (1931) about his experiences there. He later helped the Nationalists in China (1938–1940) to break Japanese codes. Following his work in China, Yardley worked briefly for the Canadian government, helping it set up a cryptological section of the National Research Council of Canada from June to December 1941. Yardley was reportedly let go due to pressure either from the Secretary of War Henry L. Stimson or from the British.
Frank Byron Rowlett was an American cryptologist.
Louis William Tordella was the longest serving deputy director of the National Security Agency.
The National Cryptologic Museum (NCM) is an American museum of cryptologic history that is affiliated with the National Security Agency (NSA). The first public museum in the U.S. Intelligence Community, NCM is located in the former Colony Seven Motel, just two blocks from the NSA headquarters at Fort George G. Meade in Maryland. The motel was purchased, creating a buffer zone between the high security main buildings of the NSA and an adjacent highway. The museum opened to the public on December 16, 1993, and now hosts about 50,000 visitors annually from all over the world.
Cryptography was used extensively during World War II because of the importance of radio communication and the ease of radio interception. The nations involved fielded a plethora of code and cipher systems, many of the latter using rotor machines. As a result, the theoretical and practical aspects of cryptanalysis, or codebreaking, were much advanced.
OP-20-G or "Office of Chief Of Naval Operations (OPNAV), 20th Division of the Office of Naval Communications, G Section / Communications Security", was the U.S. Navy's signals intelligence and cryptanalysis group during World War II. Its mission was to intercept, decrypt, and analyze naval communications from Japanese, German, and Italian navies. In addition OP-20-G also copied diplomatic messages of many foreign governments. The majority of the section's effort was directed towards Japan and included breaking the early Japanese "Blue" book fleet code. This was made possible by intercept and High Frequency Direction Finder (HFDF) sites in the Pacific, Atlantic, and continental U.S., as well as a Japanese telegraphic code school for radio operators in Washington, D.C.
William Weisband, Sr. was a Ukrainian-American cryptanalyst and NKVD agent, best known for his role in revealing U.S. decryptions of Soviet diplomatic and intelligence codes to Soviet intelligence.
A radio listening station is a facility used for military reconnaissance, especially telecommunications reconnaissance by "intercepting" radio transmitter communications. In contrast to the original eavesdropping on an acoustic speech conversation, radio eavesdropping stations are used to eavesdrop on the information transmitted wirelessly using radio technology. For this purpose, highly sensitive radio receivers and suitable receiving antennas are used.
Project SHAMROCK was the sister project to Project MINARET, an espionage exercise started in August 1945. Project MINARET involved the accumulation of all telegraphic data that entered or exited the United States. The Armed Forces Security Agency (AFSA) and its successor, the National Security Agency (NSA), were given direct access to daily microfilm copies of all incoming, outgoing, and transiting telegrams via the Western Union and its associates RCA and ITT. NSA did the operational interception, and, if there was information that would be of interest to other intelligence agencies, the material was passed to them. Intercepted messages were disseminated to the FBI, CIA, Secret Service, Bureau of Narcotics and Dangerous Drugs (BNDD), and the Department of Defense. No court authorized the operation and there were no warrants.
Station HYPO, also known as Fleet Radio Unit Pacific was the United States Navy signals monitoring and cryptographic intelligence unit in Hawaii during World War II. It was one of two major Allied signals intelligence units, called Fleet Radio Units in the Pacific theaters, along with FRUMEL in Melbourne, Australia. The station took its initial name from the phonetic code at the time for "H" for Heʻeia, Hawaii radio tower. The precise importance and role of HYPO in penetrating the Japanese naval codes has been the subject of considerable controversy, reflecting internal tensions amongst US Navy cryptographic stations.
Before the development of radar and other electronics techniques, signals intelligence (SIGINT) and communications intelligence (COMINT) were essentially synonymous. Sir Francis Walsingham ran a postal interception bureau with some cryptanalytic capability during the reign of Elizabeth I, but the technology was only slightly less advanced than men with shotguns, during World War I, who jammed pigeon post communications and intercepted the messages carried.
Arthur J. Levenson was a cryptographer, United States Army officer and NSA official who worked on the Japanese J19 and the German Enigma codes.
Vint Hill Farms Station (VHFS) was a United States Army and National Security Agency (NSA) signals intelligence and electronic warfare facility located in Fauquier County, Virginia, near Warrenton. VHFS was closed in 1997 and the land was sold off in 1999. Today the site hosts various engineering and technology companies, as well as two Federal Aviation Administration (FAA) air traffic control facilities.
Monitoring Station Designators were used by the United States Army Signals Intelligence Service to designate a specific signal intelligence monitoring station in order to allow analysts to understand the source and type of SIGINT they were analyzing. These were used as shorthand rather than writing or typing out the PLA, which consisted of the formal unit name and location of the unit who performed the signals collection.
Genevieve Marie Grotjan Feinstein was an American mathematician and cryptanalyst. She worked for the Signals Intelligence Service throughout World War II, during which time she played an important role in deciphering the Japanese cryptography machine Purple, and later worked on the Cold War-era Venona project.
Gene Grabeel was an American mathematician and cryptanalyst who founded the Venona project.
Wilma Zimmerman Davis was an early American codebreaker during World War II. She was a leading national cryptanalyst before and during World War II and the Vietnam War. She graduated with a degree in Mathematics from Bethany College and successfully completed navy correspondence course in cryptology. She began her career as a leading cryptanalyst which spanned over 30 years in the United States Army Signal Intelligence Service (SIS), a predecessor of the National Security Agency (NSA) in the 1930s. She was hired by William Friedman, who was a US cryptographer in the Army and led the research division of the Army’s Signal Intelligence in the 1930s. Wilma Davis worked as a cryptanalyst on the Italian, Japanese, Chinese, Vietnamese, and Russian problems. She also worked on the VENONA project.
