The Bill Tutte Memorial Fund has been established to provide a lasting memorial to the man who was almost single handedly responsible for the "greatest intellectual feat of World War II." If you're thinking but wasn't it Alan Turing who cracked the German Enigma code then you really need to learn about Bill Tutte. I'm not going to give you his full story (if you want that read The Universal Machine), but the short story is he worked out the internal logic of the German High Command's Lorenz machine, an encryption device much more complex than Enigma, without ever having seen what a Lorenz machine looked like.
Working at Bletchley Park, his breakthrough was put into practice by Tommy Flowers and resulted in the world's first computer, Colossus. It's widely believed that the Soviets captured several Lorenz machines as they invaded Germany and believing them invulnerable continued to use them into the 1960s, unaware that the British could crack them. This resulted in so much secrecy surrounding Lorenz, Tutte, Flowers and Colossus that even after Turing and Enigma had become part of popular history they remained unknown.