Paper on Statistics of Repetitions by Alan Turing

Date: 1945-1946 Reference: HW 25/38 (6 of 8) Creator: Records created or inherited by Government Communications Headquarters (GCHQ) Catalogue context: ALAN TURING WARTIME RESEARCH PAPERS RELEASED BY GCHQ'Paper on Statistics of Repetitions' As the country marks the centenary of Alan Turing's birth, two of his mathematical research papers, believed to have been written whilst he was at Bletchley Park during World War II, have been released by GCHQ to The National Archives.Because of continuing sensitivity the papers had been retained at GCHQ, but they have now been reassessed as suitable for release. The papers, called 'Paper on Statistics of Repetitions' and 'The Applications of Probability to Crypt', were written in an era when typographical errors would be corrected by hand and mathematical notation handwritten.The first, 'Paper on Statistics of Repetitions', is an informal report in which Turing works out the best statistical means of testing whether two cipher messages use the same key in parts of the message. This was very important in the exploitation of such messages at Bletchley Park.The second, longer, paper titled 'The Applications of Probabili... Categories: Second World War Subjects: Archives and libraries; Conflict; Intelligence; Operations, battles and campaigns Topics: Military and war Period: Postwar Copyright information: Copyright clearance for publication is not required, except in the case of documents in third-party copyright. Usage terms: https://www.nationalarchives.gov.uk/documents/information-management/use-of-tna-materials.pdf