Marian Rejewski (1905–1980) was a Polish mathematician and cryptologist who, in 1932, solved the Enigma machine, the main cipher machine then in use by Germany. While studying mathematics at Poznań University, Rejewski attended a secret cryptology course conducted by the Polish General Staff's Cipher Bureau, which he joined full-time in 1932. Rejewski and his two colleagues then developed an assortment of techniques for the regular decryption of Enigma messages, including the cryptologic " card catalog", the " cyclometer", and the cryptologic " bomb". Five weeks before the German invasion of Poland in 1939, they presented their results on Enigma decryption to their French and British counterparts. Their success jump-started British reading of Enigma in World War II, and the intelligence so gained contributed to the defeat of Nazi Germany. ( Full article...)