Cryptanalysis of the Enigma Bletchley Park to describe the network that used the same Enigma setting sheets. Initially these were recorded using coloured pencils and were given the names "red", "light blue" etc., and later the names of birds such as "kestrel". During World War II the settings for most networks lasted for 24 hours, although towards the end of the war, some were changed more frequently. The sheets had columns specifying, for each day of the month, the rotors to be used and their positions, the ring positions and the plugboard connections. For security, the dates were in reverse chronological order down the
It Was the War of the Trenches grandfather, who was a veteran of that war, and books he read about the topic. He said: "When I was small, my grandmother used to tell me stories about my grandfather in the First World War. I think the first book I read that wasn’t a picture book was a war story about an army dog who saved his master. And I still get this recurring nightmare of finding myself standing in front of a Call-Up poster - it’s a personal anxiety of mine, being caught up in a situation I can’t control." The stories focus on the daily horrors