Bletchley Park 1942 - 1945
Seminar Room 1, Newton Institute
Only a few of the many men and women who served at Bletchley Park were blessed with the genius of a Turing. For a small number of those there, the work was exciting; for many it was humdrum, boring, and unrewarding. For others it was little different from their occupations in offices of the civil service, businesses or banks.
As civilians we lived in billets, found in the villages, that were of varying styles and types of comfort. Officers of the armed forces sometimes luxuriated in hotels, or they might enjoy the hospitality of a pub whose landlady somehow evaded the restrictions of rationing. Other ranks of the services were quartered in the great houses of Bedfordshire or Buckinghamshire, or in specially built barracks. We were a mixed bag; highly distinguished scholars and mathematicians, senior officers of the armed services, eccentrics, wise men and fools, veterans long experienced in "the game." Or, as some of us were, undergraduates torn away from the dreaming spires of Oxford or the fens of East Anglia.
Codes and ciphers varied in their complexity. There were the simple systems used solely to deny information to lower ranks in the German, Italian, or Japanese armies, navies, and airforces. There were the highly refined versions of the commercially available "Enigma" machine and its successors, used in different types by commanders in the field, captains of submarines or naval attaches. In some cases, once the key to reading a message was found or broken, it could be read in entirety; for some systems the work was endless and never complete, and allowed no more than a partial reading, perhaps with the keyword (name of a place or of a ship) undecipherable.
Codes and ciphers were broken by exploiting basic information, such as the behaviour of units of a language, or predicting parts of the content of a message. Those struggling with their wits at the Park blessed the well-worn habits, the careless errors or the laziness of the cipher clerks. A basic characteristic of the Enigma machine itself led the way in. Occasionally the services themselves helped; eg, by a specially planned military operation designed to capture documents, or by laying a minefield at sea to provoke a reaction by signal.