Cryptanalysis of the Enigma by the letters on the top row of the Enigma keyboard. So, "continuation of message sent at 2330" was represented as "FORTYWEEPYYWEEPY". "Cribs" were fundamental to the British approach to solving Enigma keys, but guessing the plaintext for a message was a highly skilled business. So in 1940 Stuart Milner-Barry set up a special "Crib Room" in Hut 8. Foremost amongst the knowledge needed for identifying cribs was the text of previous decrypts. Bletchley Park maintained detailed indexes of message preambles, of every person, of every ship, of every unit, of every weapon, of every technical term and of repeated
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