Cryptanalysis of the Enigma immense problem and it gave a great deal of trouble. Work on a high speed machine had been started by Wynn-Williams of the TRE late in 1941 and some nine months later Harold Keen of BTM started work independently. Early in 1942, Bletchley Park were a long way from possessing a high speed machine of any sort. Eventually, after a long period of being unable to decipher U-boat messages, a source of cribs was found. This was the Kurzsignale (short signals), a code which the German navy used to minimize the duration of transmissions, thereby reducing the risk of being
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