双语畅销书《艾伦图灵传》第5章:解谜接力赛(13)
In 1935 the British had created Typex by adding certain attachments to it, while a few years earlier the German cryptographic authorities had modified it in a different way to create the machine which, though bearing the original name of Enigma, was much more effective than the commercially available device.
This did not mean that the German Enigma with which Alan Turing now had to grapple, was something ahead of its time, or even the best that the technology of the late 1930s could have produced
但这并不是说，艾伦·图灵现在面对的德国谜机就是领先时代的，在30年代，它并不是最先进的。The only feature of the Enigma that brought it into the twentieth century, or at least the late nineteenth, was that it was indeed 'electrical in operation'.
谜机唯一的20世纪新特性，或者说19世纪后期新特性，就是它是用电驱动的。
It used electrical wirings to perform automatically a series of alphabetical substitutions, as shown in the first figure.
它通过电路，自动执行一系列的字母替换（如下图一）。But an Enigma would be used in a fixed state only for enciphering one letter, and then the outermost rotor would move round by one place, creating a new set of connections between input and output, as shown in the second figure.
但是谜机的厉害在于，它在某个特定的状态下，只替换一个字母，然后通过外部的转盘，切换到一个新的状态。每种状态下，输入与输出之间的对应关系都是不同的（如第二图所示）。The Basic Enigma
原型版谜机For the sake of simplicity, the diagram has been drawn for an alphabet of only eight letters, although in fact the Enigma worked on the ordinary 26-letter alphabet.
为了简便起见，图中只表示了8个字母，实际中的谜机可以操作26个字母。
