cryptanalysts' tasks. A fruitful source of cribs was re-encipherments of messages that had previously been decrypted either from a lower-level manual cipher or from another Enigma network. This was called a kiss and happened particularly with German naval messages being sent in the dockyard cipher and repeated verbatim in an Enigma cipher. One German agent in Britain, Nathalie Sergueiew, code named Treasure, who had been turned to work for the Allies, was very verbose in her messages back to Germany, which were then re-transmitted on the Abwehr Enigma network. She was kept going by MI5 because this provided long cribs, not because of her usefulness as an agent to feed incorrect information to the Abwehr. Occasionally, when there was a particularly urgent need to solve German naval Enigma keys, such as when an Arctic convoy was about to depart, mines would be laid by the RAF in a defined position, whose grid reference in the German naval system did not contain any of the words (such as sechs or sieben) for which abbreviations or alternatives were sometimes used. The warning message about the mines and then the "all clear" message, would be transmitted both using the dockyard cipher and the U-boat Enigma network. This process of planting a crib was called gardening. Although cillies were not actually cribs, the chit-chat in clear that Enigma operators indulged in amongst themselves, often gave a clue as to the cillies that they might generate. When captured German Enigma operators revealed that they had been instructed to encipher numbers by spelling them out rather than using the top row of the keyboard, Alan Turing reviewed decrypted messages and determined that the word eins ("one") appeared in 90% of messages. Turing automated the crib process, creating the Eins Catalogue, which assumed that eins was encoded at all positions in the plaintext. The catalogue included every possible rotor position for EINS with that day's wheel order and plugboard connections. British bombe The British bombe was an electromechanical device designed by Alan Turing soon after he arrived at Bletchley Park in September 1939. Harold "Doc" Keen of the British Tabulating Machine Company (BTM) in Letchworth ( from Bletchley) was the engineer who turned Turing's ideas into a working machine—under the codename CANTAB. Turing's specification developed the ideas of the Poles' bomba kryptologiczna but was designed for the much more general crib-based decryption. The bombe helped to identify