"It is likely that there is further major writing by Turing yet to be released from government secrecy. One might conjecture about the following items: reports on the security of Allied cryptosystems; a 1945 report on his visit to Germany; a 1946 report for GCHQ on the potential of the digital computer he was designing at the NPL; a 1948/9 report for GCHQ commenting on Shannon's theory of communication and cryptography "