Bombe
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 Bombe facts

• The US Navy and US Army later produced their own machines to the same functional specification, but engineered differently from each other and from the British Bombe
• The initial design of the bombe was produced in 1939 at the UK Government Code and Cypher School (GC&CS) at Bletchley Park by Alan Turing, with an important refinement devised in 1940 by Gordon Welchman
• The engineering design and construction was the work of Harold Keen of the British Tabulating Machine Company
• It was a substantial development from a device that had been designed in 1938 in Poland at the Biuro Szyfrów (Cipher Bureau) by cryptologist Marian Rejewski, and known as the "cryptologic bomb" (Polish: bomba kryptologiczna)
• The bombe was designed to discover some of the daily settings of the Enigma machines on the various German military networks: specifically, the set of rotors in use and their positions in the machine; the rotor core start positions for the message—the message key—and one of the wirings of the plugboard