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The Military Encryption United Kingdom Technology

Bletchley Park Codebreaker Honored 57

Rambo Tribble writes "England has awarded Raymond Roberts, one of the nine cryptanalysts responsible for breaking the Nazi Tunny code machine, (also known by the German designation Lorenz cipher machine) the MBE. Roberts is the last surviving member of the team which cracked the German army's cipher machine functionality, much like others at Bletchley broke the better-known Enigma machine."
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Bletchley Park Codebreaker Honored

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  • Breaking Tunny (Score:5, Informative)

    by mbone ( 558574 ) on Saturday December 29, 2012 @12:32PM (#42419971)

    Tunny was broken because of a test message that had to be resent, and was re-encoded with the same key. The cryptographer was bored, and he made some abbreviations in the second encoding (which was manually typed). That put them out of phase, which meant that the message could be broken in crab-fashion. (Guess a word in the cipher text. If you are correct that gives you a little of the key and thus the decryption of the same block of characters in the other text. That, if you are lucky, will reveal another word, which gives more characters in the second text, which yields more in the first, making the entire decrypt fairly straightforward once you get going.) Breaking that message was enough to reveal how the machine worked, it was reverse engineered, and in operational use it was broken by computer basically from the start.

    All of this because one operator got sloppy on one test message that wasn't even intrinsically important anyway. But, i think it is fair to say that more crypto is broken by sloppiness than by advanced math (not that the math might not be useful in exploiting the break).

  • by v1 ( 525388 ) on Saturday December 29, 2012 @04:32PM (#42421731) Homepage Journal

    Bletchley Park could have probably gotten by without any one or two of the code breakers,

    While most of the work they did could have gone on fairly uninterrupted with the loss of any one particular person, there are some specific counter-examples. Tuttle [] took over researching a german goof in using their Lorenz set that had stumped a team there for three months, and single-handedly identified a 41 character patten that led to the breaking of Lorenz []. Without his accident/brilliance, Lorenz either would have lasted much longer, or possibly never been broken by Bletchley. (that member that was interviewed speculated the Lorenz's early break had shortened the war by 2 years, saving 20,000,000 lives)

    While this is the only specific example I can quickly quote, I would wager there are at least a handful of other points in Bletchley's history that hinged on a single member coming through with a hail-mary for the team.

Logic is the chastity belt of the mind!