Important Note: Many other excellent timelines are available online regarding the history of cryptography or WW2. Among these: US - UK collaboration; NSA pre-1952 Historical Timeline
| Year | Month | Event |
|---|---|---|
| 1919 | Hugo Koch, a Dutchman, comes up with the idea for the Enigma cipher machine | |
| 1921 | William Friedman goes to work for the Army Signal Corps | |
| 1923 | Arthur Scherbius produces a n Enigma machine for the commercial market | |
| 1924 | January | Lt. Laurence Safford takes the head of the Reseach Desk at the US Navy Codes and Signal Section (later became Op-20-G) |
| 1925 | First US Navy radio intercept station set up on Guam followed by two in the Philippines and one in Shanghai | |
| Joseph Rochefort assigned to the Research desk | ||
| 1928 | July | The "On the Roof Gang" begins training on the roof of the old Navy Department. |
| 1930 | April | William Friedman authorized to hire three junior cryptanalysts to begin a bureau known as the Signal Intelligence Service |
| 1931 | Japanese cryptographers begin use of an "unbreakable" cipher called "Red" produced by a machine using rotors with a complex wiring arrangement | |
| 1932 | In Poland, Marian Rejewski recovers wiring of Geman military Enigma rotors | |
| 1936 | Red system broken by US Navy | |
| 1937 | Introduction of the Purple Japanese cipher machine | |
| 1938 | April | Harry Williams, at the request of Col. Edward A. Deeds, President of the National Cash Register Company, hired Joseph R. Desch to begin NCR's Electrical Research Laboratory |
| 1939 | 15 March | Germany invades Czechoslovakia |
| 1 June | The Japanese naval code JN-25 introduced | |
| 1 September | Germany invades Poland | |
| 3 September | France and Britain declare war | |
| 1940 | By the summer of 1940, through the collaboration of the staff of William Friedman of the SIS and Lt Safford Japanese diplomatic traffic was easily read | |
| 14 March | First bombe operational at Bletchley Park | |
| summer | Battle of Britain | |
| September | Japanese Purple cipher broken by US Army; first JN-25 decrypts by Op-20-G | |
| October 2 | Joseph Desch writes in December to Dr. George Harrison of the NDRC that on October 2nd his laboratory staff--Mr. Robert Mumma and Mr. Louis DeRosa--are beginning work on the development of high speed electronic counters. | |
| 1941 | March | The National Defense Research Committe appoints Joseph Desch an "Official Investigator" and requires him to sign the first of a series of pledges of secrecy |
| 1941 | June | Joseph Rochefort takes command of the radio intelligence unit of the 14th Naval District in Hawaii, renaming it the Combat Intelligence Unit |
| October | Desch's lab develops a counting bank, using his thyratron tubes, capable of counting at 1,000,000 impulses per second (1 MH in today's terms). Desch presents a talk on this topic in December at an Electronic Counter Conference in Washington. George Harrison of the Instruments Section of the NDRD later write Desch that his talk was "quite effective".(NCR Archive) | |
| 1942 | March | US Navy and National Cash Register Company sign a contract to develop and construct specialized machines. This contract establishes the Naval Computing Machine Laboratory (Wilcox, The Cryptanalytic Bombe) |
| June | More than 600,000 tons of shipping were sunk (Budiansky, Battle of Wits, p. 236). This was close to Admiral Doenitz's goal of 700,000 which he felt would cripple Britain | |
| September 4 | US Navy approves the plan for bombe construction (Budiansky, p. 343) | |
| December | The total figures of Allied losses during 1942 in the Atlantic: 1,664 ships, of 7,790,691 tons. U-boats alone sank 1,160 ships and 6,226,215 tons.(Parrish, The Ultra Americans) | |
| 1943 | April | WAVES begin arriving by train at Union Station in Dayton to report for duty at the US NCML. |
| May 2 | First two US Navy bombes at the USNCML begin tests (Budiansky, p. 343) | |
| 31 August | first US Navy bombes arrive in Washington (Budiansky, p. 344) | |
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Latest update October 21, 2008