Meet Leo Marks, WW2 cryptographer, who was given a 20 minute training exercise on his first day at work which took him the whole day to complete. He had accidentally not been given the cipher key and ended up breaking a code that was meant to be secure.

Leo Marks

Leo Marks, who was codes and ciphers chief at the Special Operations Executive (SOE) during the second world war, and worked closely with agents dropped behind enemy lines, has died aged 80. He also pursued a long and sometimes controversial postwar career as a writer for stage and screen, culminating in the film Peeping Tom, which hurt the reputation of its leading British director, Michael Powell.

Obeying Churchill’s order to “set Europe ablaze”, SOE, a parallel secret service run by a mixture of brilliant brains and bungling amateurs, sent spies into occupied Europe to gather information and work with resistance groups. Casualties were high, as when the Germans penetrated its Dutch network and executed some 50 agents, despite warning… Continue Reading (6 minute read)

11 thoughts on “Meet Leo Marks, WW2 cryptographer, who was given a 20 minute training exercise on his first day at work which took him the whole day to complete. He had accidentally not been given the cipher key and ended up breaking a code that was meant to be secure.”

  1. Dozhet

    > Marks’s deduction that the Germans had broken into the Dutch network was based on the fact that all messages from Holland in 1943 came across without a single error. He ended one dummy message to Holland with the letters HH, a common German sign-off standing for Heil Hitler. When the reply carried the automatic HH, he knew there was a German on the key.

  2. depressive-duck

    like that guy that copied and solved some unsolved math problems on the blackboard at school because he was late and thought they were homework

  3. MrEmouse

    Took **one** guy **one** day to break the cypher… Yeah, I bet they didn’t feel very secure after that.

  4. DiveBard

    After the war he went on to write the script for the film Peeping Tom.

  5. Cuaroc

    Is this prime task failed successfully material

  6. rubber-tentacle

    Cryptonomicon Inspiration?

  7. Sugarkrill

    To be fair, they were using a ROT-26 cypher.

  8. aussielander

    Depressing read towards the end, guy peaked in his early 20s.

  9. IHaveARightToKillYou

    Pfft. Yeah, but it took him all day.

  10. CzechMate9104

    Reminds me of the mathematician who solved 2 supposed unsolvable problems after he got to class late and his buddy joked that the questions were home work.

  11. dezzz

    And his name? Albert Einstein.

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