It can be argued that Bletchley Park from 1939 to 1945 housed the greatest aggregation of brainpower ever in one place at one time. Among that crowd of intellectuals was a theoretician whose concepts underpin seventy years of computing, and whose work turned sophisticated encrypted messages into actionable intelligence, contributing to victory in World War II. This was Alan Turing.
At Britain's Government Code & Cypher School, Dr. Turing developed an analytic approach for the ENIGMA that would outlast German operational changes. He also took responsibility for the naval ENIGMA problem, which nobody had yet solved. He developed an early solution and became operational chief of Hut 8, the naval cryptanalysts.
Dr. Turing's interest in artificial intelligence led him to develop the "Turing Machine," which is still used as a basic teaching device in computer science. During World War II his theories about machines in analysis were used to develop COLOSSUS, which processed very high-grade enciphered communications and that many consider the world's first operational computer.
Dr. Turing made no attempt to hide his homosexuality, and he was accepted without hesitation by his colleagues. However, because homosexual acts were illegal in Great Britain at the time, he faced legal repercussions. He eventually took his own life.
Dr. Turing's cryptologic accomplishments in World War II saved thousands of lives and shortened the war, while his theories and work led to development of the modern computer. His towering achievements changed cryptology and the world at large, and continue to do so today.