If you just scramble a sentence, it's pretty useless because the recipients are never going to be able to reverse the process.

如果你只是加密一个句子，这是毫无用处的,因为收件人没法将这个句子,反加密出来。

哈佛公开课 - 计算机科学课程节选

We don't know the intended recipient of this letter, and we actually have no idea whether Milton actually sent the letter; but a couple of drafts of this letter actually exist in Milton's own hand, and the letter is clearly a document that Milton had devoted some energy and some time to. We need to look at it.

我们不知道收件人是谁，我们也不清楚弥尔顿到底有没有寄这封信;,但这份信的草稿确实在弥尔顿那里，弥尔顿显然对这封信投入了不少,时间和精力，我们来看看。

耶鲁公开课 - 弥尔顿课程节选