Ultra was the designation adopted by British military intelligence in June 1941 for wartime signals intelligence obtained by breaking high-level encrypted enemy radio and teleprinter communications at the Government Code and Cypher School (GC&CS) at Bletchley Park. Ultra eventually became the standard designation among the western Allies for all such intelligence. The name arose because the intelligence obtained was considered more important than that designated by the highest British security classification then used and so was regarded as being Ultra Secret. Several other cryptonyms had been used for such intelligence.
In the history of cryptography, the "System 97 Typewriter for European Characters" (九七式欧文印字機) or "Type B Cipher Machine", codenamed Purple by the United States, was an encryption machine used by the Japanese Foreign Office from February 1939 to the end of World War II. The machine was an electromechanical device that used stepping-switches to encrypt the most sensitive diplomatic traffic. All messages were written in the 26-letter English alphabet, which was commonly used for telegraphy. Any Japanese text had to be transliterated or coded. The 26-letters were separated using a plug board into two groups, of six and twenty letters respectively. The letters in the sixes group were scrambled using a 6 × 25 substitution table, while letters in the twenties group were more thoroughly scrambled using three successive 20 × 25 substitution tables.
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.
Frank Byron Rowlett was an American cryptologist.
Magic was an Allied cryptanalysis project during World War II. It involved the United States Army's Signals Intelligence Service (SIS) and the United States Navy's Communication Special Unit.
Bethany College is a private liberal arts college in Bethany, West Virginia. Founded in 1840 by Alexander Campbell of the Restoration Movement, who gained support by the Virginia legislature, Bethany College was the first institution of higher education in what is now West Virginia.
Various conspiracy theories allege that U.S. government officials had advance knowledge of Japan's December 7, 1941, attack on Pearl Harbor. Ever since the Japanese attack, there has been debate as to why and how the United States had been caught off guard, and how much and when American officials knew of Japanese plans for an attack. In September 1944, John T. Flynn, a co-founder of the non-interventionist America First Committee, launched a Pearl Harbor counter-narrative when he published a 46-page booklet entitled The Truth about Pearl Harbor, arguing that Roosevelt and his inner circle had been plotting to provoke the Japanese into an attack on the U.S. and thus provide a reason to enter the war since January 1941.
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.
The Signal Intelligence Service (SIS) was the United States Army codebreaking division through World War II. It was founded in 1930 to compile codes for the Army. It was renamed the Signal Security Agency in 1943, and in September 1945, became the Army Security Agency. For most of the war it was headquartered at Arlington Hall, on Arlington Boulevard in Arlington, Virginia, across the Potomac River from Washington (D.C.). During World War II, it became known as the Army Security Agency, and its resources were reassigned to the newly established National Security Agency (NSA).
The Central Bureau was one of two Allied signals intelligence (SIGINT) organisations in the South West Pacific area (SWPA) during World War II. Central Bureau was attached to the headquarters of the Allied Commander of the South West Pacific area, Douglas MacArthur. Central Bureau's role was to research and decrypt intercepted Imperial Japanese Army traffic and work in close co-operation with other SIGINT centres in the USA, United Kingdom and India. Air activities included both army and navy air forces, as there was no independent Japanese Air Force.
Wyandotte High School is a fully accredited public high school located in Kansas City, Kansas, United States. It serves students in grades 9 to 12 and operated by the Kansas City USD 500 school district. The building itself is a historic and notable public building, which was listed on the National Register of Historic Places in 1986. The school principal is Mary Stewart. The mascot is the Bulldog and the school colors are red and white.
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.
The Military Intelligence Service was a World War II U.S. military unit consisting of two branches, the Japanese American unit and the German-Austrian unit based at Camp Ritchie, best known as the "Ritchie Boys". The unit described here was primarily composed of Nisei who were trained as linguists. Graduates of the MIS language school (MISLS) were attached to other military units to provide translation, interpretation, and interrogation services.
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.
Japanese army and diplomatic codes. This article is on Japanese army and diplomatic ciphers and codes used up to and during World War II, to supplement the article on Japanese naval codes. The diplomatic codes were significant militarily, particularly those from diplomats in Germany.
Mary Louise Prather was an American spy and one of the pioneering women within the field of cryptography. Most of her work in the field of cryptography was completed during World War II and early in the Cold War era.
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.
The United States Coast Guard Unit 387 became the official cryptanalytic unit of the Coast Guard collecting communications intelligence for Coast Guard, U.S. Department of Defense, and the Federal Bureau of Investigation (FBI) in 1931. Prior to becoming official, the Unit worked under the U.S. Treasury Department intercepting communications during the prohibition. The Unit was briefly absorbed into the U.S. Navy in 1941 during World War II (WWII) before returning to be a Coast Guard unit again following the war. The Unit contributed to significant success in deciphering rum runner codes during the prohibition and later Axis agent codes during WWII, leading to the breaking of several code systems including the Green and Red Enigma machines.
The Code Girls or World War II Code Girls is a nickname for the more than 10,000 women who served as cryptographers and cryptanalysts for the United States Military during World War II, working in secrecy to break German and Japanese codes.
