Henryk Zygalski

Henryk Zygalski
Henryk Zygalski about 1930
Born	(1908-07-15)15 July 1908 Posen, German Empire
Died	30 August 1978(1978-08-30) (aged 70) Liss, England
Nationality	Polish
Occupation	Mathematician, cryptologist

Henryk Zygalski (Polish pronunciation: [ˈxɛnrɨk zɨˈɡalski]; 15 July 1908 in Posen – 30 August 1978 in Liss) was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II.

Zygalski was, from September 1932, a civilian cryptologist with the Polish General Staff's Biuro Szyfrów (Cipher Bureau), housed in the Saxon Palace in Warsaw. He worked there with fellow Poznań University alumni and Cipher Bureau cryptology-course graduates Marian Rejewski and Jerzy Różycki. Together they developed methods and equipment for breaking Enigma messages. In late 1938, in response to growing complexities in German encryption procedures, Zygalski designed the "perforated sheets," also known as "Zygalski sheets," a manual device for finding Enigma settings. This scheme, like the earlier "card catalog," was independent of the number of connections being used in the Enigma's plugboard, or commutator. After the war he remained in exile in the United Kingdom and worked, until his retirement, as a lecturer in mathematical statistics at the University of Surrey. During this period he was prevented by the Official Secrets Act from speaking of his achievements in cryptology. He died on 30 August 1978 at Liss; after his cremation his ashes were taken to London.