"Enigma M4" Cypher Machine, c. 1942

4-rotor naval Enigma machine, no. M 4609, by Chiffriermaschinengesellschaft Heimsoeth und Rinke, Berlin ("jla"), rotor no. M 4609 III, VI and VII, extra wheel Gamma, reflector wheel UKW-B, numbered plug board, connector to external 4V line, removable lamp panel, lamps replaced. Included is a group of related documents in copy. – Very good original working condition, electrical functions checked. An important example of the legendary World War II ciphering machine developed by Berlin engineer Dr. Arthur Scherbius and first manufactured there commercially by the Chiffriermaschinen Aktiengesellschaft Berlin in 1923. So complex was the Enigma, it was considered capable of producing over 22 billion code combinations without a single repetition. According to an early prospectus, "if someone worked continuously day and night and tried a different cipher-key every minute, it would take him 42,000 years to exhaust all combination possibilities". In operation, each keystroke illuminated a different character and caused one or more rotors to shift fractionally, so that a different combination was created every time. Decryption required codebooks and a list of daily key settings. The more secure 4-rotor Enigma, developed exclusively for the German Navy, was incorporated into Atlantic submarines in 1942. The seemingly impenetrable cyphers posed a serious challenge to the British armed forces until their capture of the abandoned U-559 in October 1942 altered the course of the war. – The captured submarine yielded not only an Enigma machine, but also its key-settings. Thanks to this discovery, Allied Forces were now able to decrypt intercepted German naval cypher. In order to disguise this fact from the German military, British Intelligence Services valorized the work of mathematicians Alan M. Turing and Alfred Knox, who continued to work on decryption methods with the first programmable electromagnetic computer ("The Bombe") at Bletchley Park. – The techniques of the British mathematicians were indebted to the work of Polish cryptologist Marian Rejewski and his colleagues, who had cracked the code of the 3-rotor Enigma machine as early as 1932 by rebuilding an Enigma machine! Turing had no progress till the Polish solutions and hand-made Enigma copies were brought to Bletchley park in 1939! The British "Bombe" was in fact an improved version of the Polish "Bomba" already in use since 1940. The available "Bombes" were fast enough for deciphering the codes of the 3-rotor Enigma used by the airforce, but too slow to make headway with the 4-rotor machines which employed each code book for a short time only. The result was the development of Turing's programmable computer in its first form (named "Colossus") – in use from December 1943. – An important artifact and milestone of military history!

布雷克拍品等级是为了方便竞买人判断拍卖品的成色而设置的。布雷克等级用1到6级来标注外观和功能的成色，(从非常好到非常差)。 在目录图册里用括号里的2个数字来表示，前一个数字表示外观成色的级别，后一个数字表示功能成色的级别。如(3/2)表示外观成色是3(满意的)，功能成色2(好)。 成色 定义参照下列标准： 1 - 非常好 (未使用过，没有使用痕迹) 2 - 好 (新，极少的使用痕迹) 3 - 满意的 (普通的使用痕迹) 4 - 及格的 (明显的使用痕迹，某个非主要部件是后配的) 5 - 有缺陷的 (极明显的使用痕迹, 某个主要部件是后配的，功能上有缺陷，需要修理) 6 - 非常差 (严重破损, 缺少重要部件)