• germans created the machine

    1915, two Dutch Naval officers invented a machine to encrypt messages. This became known as the Enigma machine.
  • arthur scherbius patented the enigma machine

    1918, Arthur Scherbius, a German businessman, patented the Enigma machine.
  • production of the enigma machine

    Mid 1920s, mass production of Enigma machine with 30,000 machines being sold to the German military over the next 2 decades.
  • the poles set up a world leading crypt analysis

    The Poles set up a world leading crypt analysis bureau and hired leading mathematicians such as Marian Rejewski.
  • german army used the machine

    Enigma machine adopted by the German army
  • marian rejewski recovers the machine

    Late 1932 Polish Cryptanalyst Marian Rejewski recovers the entire machine wiring by mathematical analysis using a group of intercepts and machine settings for two months, September and October 1932, supplied by the French.
  • replacement

    On 2nd November Umkehrwalze B was introduced, replacing Umkehrwalze A and this remained in use until the end of the war in 1945
  • each message changed

    On September 15th the fixed daily Grundstellung was dropped. Each message must now have a different Grundstellung selected by the operator. The message header would contain three trigrams, the Grundstellung followed by the double enciphered message key enciphered using the message Grundstellung
  • iv and i wheels were changed

    On 15th December wheels IV and V were added. Three wheels could now be selected from a set of five - giving 60 possible arrangements. A different wheel arrangement could now be used for every day of the month. The two additional wheel wirings were quickly recovered by Rejewski
  • plugboard number increased

    On 1st January the number of plugboard connections was increased from six to ten
  • entering service

    The First Welchman-Turing Bombe enters service in March.
  • the enciphered message

    On 1st May the double enciphered message key was dropped. The Message key was only enciphered once from now on. The message header would contain two trigrams, the message Grundstellung followed by the enciphered message key.