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Two of Alan Turing’s Secret Code-Breaking Essays Released by U.K. Government

One of the early pioneers of computer science, Alan Turing is best known for his work on breaking the Nazi Enigma code during the Second World War. His work for the British code-breaking outfit Bletchley Park during that time are considered fundamental to modern cryptography — so much so that some of his work has remained under wraps for nearly 70 years. Now, in celebration of what would have been Turing’s 100th birthday, two of his foundational essays on code breaking have been released by the U.K. government.

The essays, titled “Paper on Statistics of Repetitions” and “The Applications of Probability to Crypt,” are highly detailed works and have been the property of the British signals intelligence organization called the Government Communications Headquarters (GCHQ). In addition to their scholarly and historical value, the papers with their hand-written mathematical notations and corrections provide an intimate link to a piece of modern secret history.

For Enigma buffs, “Paper on Statistics of Repetitions” is sure to be an interesting read, as it relates directly to code-breaking methodologies used on the Nazi cypher. Interestingly, it is not an all-encompassing paper on how to break the Enigma code, but referes specifically to finding a means to determine the settings on the Enigma machine used to encode a message. It provides a means to compare two messages and determine if they were coded with machines at the same settings.

The second paper, “The Applications of Probability to Crypt,” has a much wider scope and demonstrates how probability analysis could be applied to code breaking. Intriguingly, the paper uses the age of Adolf Hitler as an example saying, “Hitler is now 52,” which means that the paper was written some time between 1941 and 1942. Though broad in scope, the GCHQ says that this paper was likely fundamental to the work being done at Bletchley park at the time.

Unfortunately, the papers have not been released online. The curious will have to make their way to the British National Archives reading area, and view the papers in person.

During and after the war, Turing would do foundational work that would eventually lead to the advent of modern computing. However, he did not live to see it. As a homosexual, he was prosecuted under Britain’s brutal laws at the time and accepted chemical castration as opposed to prison in 1952 — two years before his controversial death from cyanide poisoning. In recent years, the British government has apologized for his treatment after a public outcry.

This document release, though small, sheds light not only on the work being done behind the scenes that helped sway the outcome of the Second World War, but also acknowledges the amazing contributions of this truly singular man.

(BBC via Gizmodo, GCHQ, image via the British National Archives)

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