雙語暢銷書《艾倫圖靈傳》第5章:解謎接力賽(42)

The Turing Bombe

圖靈炸彈機

Suppose now that the letters LAKNQKR are known to be the encipherment of GENERAL on the full Enigma with plugboard.

假設現在已知，有一臺帶有配線板的完整謎機將GENERAL編碼成了LAKNQKR。

This time there is no point in trying out LAKNQKR on the basic Enigmas, and looking at what emerges, for some unknown plugboard swapping must be applied to LAKNQKR before it enters the Enigma rotors.

因爲GENERAL在進入轉盤之前，已經執行了一些未知的配線對換，所以現在不能在原型謎機中進行檢查。

Yet the quest is not hopeless. Consider just one letter, the A.

但是我們還有別的希望。先只考慮一個字母A。

There are only 26 possibilities for the effect of the plugboard on A, and so we can think about trying them out.

配線板對A的改變只有26種可能，所以我們可以考慮把它試出來。

We may start by taking the hypothesis (AA), i.e. the supposition that the plugboard leaves the letter A unaffected.

我們先假設（AA），也就是假設配線板不影響字母A。

What follows is an exploitation of the fact that there is only one plugboard, performing the same swapping operation on the letters going into the rotors as on the letters coming out.

接下來，利用這樣一個事實：字母在進入轉盤之前，和從轉盤出來之後，經過的是同一個配線板。

(If the Enigma had been fitted with two different plugboards, one swapping the ingoing letters and one the outcoming, then it would have been a very different story.)

如果謎機用了兩個不同的配線板，一個負責對換輸入前的字母，另一個負責對換輸出後的字母，那麼這個故事就完全不一樣了。

It also exploits the fact that this particular illustrative 'crib' contains a special feature—a closed loop.

還要利用一個事實，在下面的像一組"牀位"一樣的圖中，存在一種很特殊的特性——閉合迴路。

This is most easily seen by working out the deductions that can be made from (AA).

我們從（AA）出發，進行一些推導，就很容易看到這一點。