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
United States Coast Guard Unit 387 Cryptanalysis Unit the neutrality laws. Throughout WWII, the unit used HFDF technology to intercept approximately 10,000 enemy communications from 65 German clandestine networks and played a key role in cracking the “Enigma G” Code of the Green Enigma, the Red Enigma, the Berlin-Madrid Machine, and the Hamburg-Bordeaux Stecker codes. Their HFDF stations expanded to cover the United States with 20 primary stations, nine secondary stations, six contributory stations, and five Coast Guard radio stations. The USCG also had Cutters, trucks, briefcases, and handbags with HFDF technology inside to track “wildcat” stations across the US. The FBI Director J. Edgar Hoover believed that