Perhaps foreshadowing our own information age, World War II’s “Battle of the Atlantic” between German submarine wolf-packs and Allied convoys was largely won and nearly lost by the code breakers of Bletchley Park. In 1940, Alan Turing had begun to break the German Navy’s “Dolphin” cipher which was based on an Engima code machine with three encoding rotors. Within a little over a year the German wolf-packs were temporarily withdrawn due to mounting submarine losses. In 1942, however the Germans introduced a new four rotor Engima machine using what was termed the “Shark” cipher. Richard Pendered and a small team of codebreakers would finally break the “Shark” cipher ending a ten month period of major Allied convoy losses in what those in Bletchely Park referred to as the “Shark blackout.”
Richard Pendered, who has died aged 89, was one of the small team of Bletchley Park codebreakers who broke the “Shark” Enigma cipher used by German U-boats during the Second World War; his work also led directly to the sinking of the battlecruiser Scharnhorst.
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