Enigma Was Broken by Polish Mathematicians First

Seven years before WWII, 23-year-old Marian Rejewski used permutation group theory to reverse-engineer the German Enigma machine without ever seeing one. He and colleagues built replica machines and the Bomba code-breaking device. In July 1939 they secretly handed all research to British intelligence. Rozycki died when torpedoed in 1942. Rejewski and Zygalski were barred from Bletchley Park.