Enigma machine, Bletchley Park, Ultra, Lorenz cipher, Cryptanalysis of the Enigma, Magic, OP-20-G, Station HYPO, Japanese naval codes, Fish, Far East Combined Bureau, Beaumanor Hall, The National Museum
Source: Wikipedia. Pages: 58. Chapters: Enigma machine, Bletchley
Park, Ultra, Lorenz cipher, Cryptanalysis of the Enigma, Magic,
OP-20-G, Station HYPO, Japanese naval codes, Fish, Far East
Combined Bureau, Beaumanor Hall, The National Museum of Computing,
Siemens and Halske T52, German code breaking in World War II,
Station CAST, United States Naval Computing Machine Laboratory,
World War II cryptography, PC Bruno, Signals Intelligence Service,
Reservehandverfahren, B-Dienst, Wireless Experimental Centre.
Excerpt: Cryptanalysis of the Enigma enabled the western Allies in
World War II to read substantial amounts of secret Morse-coded
radio communications of the Axis powers that had been enciphered
using Enigma machines. This yielded military intelligence which,
along with that from other decrypted Axis radio and teleprinter
transmissions, was given the codename Ultra. This was considered by
western Supreme Allied Commander Dwight D. Eisenhower to have been
"decisive" to Allied victory in World War II. The Enigma
machines were a family of portable cipher machines with rotor
scramblers. Good operating procedures, properly enforced, would
have made the cipher unbreakable. However, most of the German armed
and secret services and civilian agencies that used Enigma employed
poor procedures. It was the poor operating procedures that allowed
the cipher to be broken. The German plugboard-equipped Enigma that
would become the Third Reich's principal crypto-system was
reconstructed with the aid of French-supplied intelligence material
that had been obtained from a German spy by the Polish General
Staff's Cipher Bureau in December 1932. From then until the
outbreak of World War II, the Poles held a monopoly in decrypting
German military Enigma ciphers. In July 1939, as war drew near, the
Polish Cipher Bureau initiated the French and British into its
Enigma-breaking techniques and technology at a conference held in
Warsaw. From this beginning, the British Government Code and Cypher
School at Bletchley Park built up an extensive cryptanalytic
facility that used manual methods and machines "Bombes".
Initially, the decryption was mainly of Luftwaffe and a few Army
messages, as the German Navy employed much more secure procedures
for using Enigma. Alan Turing, a Cambridge University mathematician
and logician, provided much of the original thinking that led to
the design of the Bombes and the eventual breaking of naval Enigma.
However, when the German Navy introduced an Enigma version with
