雙語暢銷書《艾倫圖靈傳》第4章:彼岸新星(56)
This was Malcolm MacPhail, a Canadian physicist, who became involved in a sideline that Alan took up.
It was probably in the fall of 1937 that Turing first became alarmed about a possible war with Germany.
大概是在1937年的秋天，圖靈首先警覺，德國可能會引發一場戰爭。He was at that time supposedly working hard on his famous thesis but nevertheless found time to take up the subject of cryptanalysis with characteristic vigour.
那時，他除了埋頭工作於他著名的論文之外，還發揮他的智力，抽時間研究密碼學。
…on this topic we had many discussions.
在這方面，我們討論了很多。He assumed that words would be replaced by numbers taken from an official code book and messages would be transmitted as numbers in the binary scale.
他想到，通過一個約定的密碼手冊，可以把單詞轉化成數，這樣就可以把一條信息轉化成一串二進制數。But, to prevent the enemy from deciphering captured messages even if they had the code book, he would multiply the number corresponding to a specific message by a horrendously long but secret number and transmit the product.
爲了讓敵人即使掌握了密碼手冊也不能破解信息，就要把這個代表特定信息的數，乘以一個非常大的密鑰數，然後傳輸它們的乘積。The length of the secret number was to be determined by the requirement that it should take 100 Germans working eight hours a day on desk calculators 100 years to discover the secret factor by routine search!
這個密鑰數的長度，可以根據需要來設定，應該保證在一個德國人每天用臺式計算器工作8小時的情況下，需要花費100年才能算出這個密鑰。Turing actually designed an electric multiplier and built the first three or four stages to see if it could be made to work.
實際上，圖靈還設計了一個電動乘法機，並且製造了前三個或四個模塊，來試驗它是否能工作。For the purpose he needed relay-operated switches which, not being commercially available at that time, he built himself.
爲了實現這個計劃，他需要一種繼電器開關，當時在市場上買不到，於是他要自己製作。
