- Those of you with backgrounds in history or we've seen -- or remember World War II with technologies that were used in it might know of the Enigma machine, which is kind of the same idea.

你们其中有历史背景的人或者我们看到的-,或记得起的第二次世界大战中使用的,可能知道的英格玛装置，那是一种同样的思想。

哈佛公开课 - 计算机科学课程节选

If you have some plain text, some message that you want to send, well, you can encrypt it or you can scramble it using a key, a secret key, which might be a physical machine like the Enigma 13 or it might be a number like 13.

如果你有没有加密的文本，你想要寄送的一些消息,你就可以加密它,或者你可以用一个密钥使其变得混乱，那就像一个英格玛的物理装置,或者他就是一个数字。

哈佛公开课 - 计算机科学课程节选