Polish Enigma double

Enigma "doubles" were machines produced by the Polish Cipher Bureau. They replicated the functions of German Enigma rotor cipher machines, following Marian Rejewski's remarkable achievement in deriving its wirings.

Built in Poland

By the end of 1932, Rejewski, aided by spy-supplied documents, had derived the internal wiring of the Enigma machine. This information would allow the Polish to build their own copies of the machine. In February 1933, the Polish Cipher Bureau ordered fifteen "doubles" of the military Enigma machine to be produced by the AVA Radio Manufacturing Company, in Warsaw. Ultimately, about seventy such functional replicas would be produced.

Precious gift

In August 1939, following the tripartite meeting of the French, British and Polish cryptanalysts held near Warsaw on 25 and 26 July, two Enigma replicas were passed to Poland's allies, one being sent to Paris and one to London. Until then, German military Enigma traffic had defeated the British and French, and they had faced the disturbing prospect that German communications would remain "black" to them for the duration of the coming war.

Built in France

After Germany invaded Poland in September 1939 and key Polish Cipher Bureau personnel evacuated to France, the Cipher Bureau resumed its interrupted work at PC Bruno, outside Paris. The Poles had only three replica Enigma machines to work with, and these were wearing out from round-the-clock use. French Army intelligence officer Gustave Bertrand ordered parts for forty machines from a French precision-mechanics firm. Manufacture proceeded sluggishly, however, and it was only after the fall of France and the opening of underground work in southern France's Free Zone in October 1940 that four machines were finally assembled.

See also

• Saxon Palace (Polish: Pałac Saski), in Warsaw, where German Enigma ciphers were first broken in December 1932

References

• Brzezinski, Zbigniew (2005). "The Unknown Victors". Marian Rejewski, 1905-1980: Living with the Enigma Secret. Bydgoszcz: Bydgoszcz City Council. pp. 15–18. ISBN 83-7208-117-4. OCLC 62701914.
• Kozaczuk, Władysław (1984). Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two. Foreign intelligence book series. Frederick, Md.: University Publications of America. ISBN 0-89093-547-5. OCLC 9826775. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Woytak, Richard A. (January 1982). "A Conversation with Marian Rejewski". Cryptologia. 6 (1): 50–60. doi:10.1080/0161-118291856830. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)