Gibbons Lecture Series: Alan Turing and the Secret Cyphers
Breaking the German Codes at Bletchley Park
Speaker: Professor Jack Copeland, Department of Philosophy, The University of Canterbury
Jack Copeland received his D.Phil. in Philosophy from the University of Oxford. He is Professor of Philosophy and Director of the Turing Archive for the History of Computing at the University of Canterbury. His publications include the books The Essential Turing; Alan Turing's Automatic Computing Engine; Colossus: The Secrets of Bletchley Park's Codebreaking Computers; and more than 100 articles on the philosophy and history of computing, the philosophy of mind, and philosophical logic.
Synopsis: In 1939 Turing was recruited to work on deciphering enemy codes at Bletchley Park. He disappeared from the public record and it was only many years later that it was widely known what he had accomplished. Turing initially worked on cracking the German "Enigma" codes which involved his devising electro-mechanical special-purpose computing machines known as "bombes". He had a hand in many aspects of the British code-breaking efforts, some involving the beginnings of information theory. Although not directly involved in the hardware design he had full knowledge of Bletchley's electronic computing machines; he later moved on to work on voice scramblers, teaching himself electronics along the way.
The story of the Enigma cipher machine and its defeat by the Bletchley Park code-breakers astounded the world. This lecture also describes Bletchley's success against a later, more advanced German cipher machine that the British codenamed Tunny. Unlike Enigma, which dated from 1923 and was marketed openly throughout Europe, the ultra-secret Tunny was created by scientists of Hitler's Third Reich for use by Hitler and his generals. Central to the Bletchley attack on Tunny was Colossus, the world's first large-scale electronic digital computer.