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 countries used Enigma machines. The Italian Navy adopted the commercial Enigma as "Navy Cipher D". The Spanish also used commercial Enigma during their Civil War. British codebreakers succeeded in breaking these machines, which lacked a plugboard. Enigma were also used by diplomatic services. There was also a large, eight-rotor printing model, the "Enigma H", called "Enigma II" by the "Reichswehr". In 1933 the Polish Cipher Bureau detected that it was in use for high-level military communications, but that it was soon withdrawn, as it was unreliable and jammed frequently. The Swiss used a version of Enigma called "model K" or