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
Enigma machine Enigma variant was a four-wheel unsteckered machine with multiple notches on the rotors. This model was equipped with a counter which incremented upon each key press, and so is also known as the "counter machine" or the "Zählwerk" Enigma. Enigma machine G was modified to the "Enigma I" by June 1930. Enigma I is also known as the "Wehrmacht", or "Services" Enigma, and was used extensively by German military services and other government organisations (such as the railways) before and during World War II. The major difference between "Enigma I" (German Army version from 1930), and commercial Enigma models was