All Seasons

Season 1

  • S01E01 The Keys to the Reich

    • Channel 4

    This episode covers the early allied efforts at cracking the German Enigma system, the establishment of Station X at Bletchley Park and the gathering of the eclectic group of geniuses who were to break the "unbreakable" German Enigma encryption system. The programme gives insight into the inner-workings of the Enigma machine, and the manner in which Bletchley's brilliant boffins managed to outsmart it.

  • S01E02 The Goose that Laid the Golden Eggs

    • Channel 4

    This episode looks at Alan Turing's singular contribution to the codebreaking effort (and to computer science more broadly) and the events leading up to the breaking of the German Naval encryption system. It includes interviews of several individuals directly involved in effort.

  • S01E03 The Ultra Secret

    • Channel 4

    This episode shows further progress in the cracking of the German codes, including the extensive use of 'cribs' and the algorithm solving Bombe machine devised by Alan Turing. A reunion of WRENS recalls their memories of working the Bombes, locating the rotor wheels onto the machines (and cleaning the wire contacts when they stuck), and plugging up the stecker-boards from the crib menus. They used the following phonetic alphabet : Apple, Butter, Charlie, Dan, Edward, Freddie, George, Henry, Ingrid, James, Kenneth, London, Monkey, Nuts, Oliver, Peter, Quagga, Robert, Sugar, Tommy, Unicorn, Vinegar, Willie, X-ray, Yellow, Zebra. The information obtained from all these sources was of course 'ultra top secret' and had to remain so otherwise the Germans might reconfigure the Enigma. Winston Churchill referred to this intelligence as his 'Ultra.'

  • S01E04 The War of the Machines

    • Channel 4

    Looks at the breaking of Shark and other Fish codes using the Tunny machine and the development of Colossus, which became the world's first electronic programmable computer. All of these efforts resulted in a shortening of the war by several years. In order to keep the secret of 'Ultra' safe, all of the machines and paperwork were destroyed at the end of the war. However, that's not quite all of the story...