没有一个真正安全的居住区。

There is no neighbourhood which is really safe.

《柯林斯英汉双解大词典》

客载量这么大，有一个问题非常突出——安全。

With these very large passenger payloads one question looms above all others – safety.

《柯林斯英汉双解大词典》

安全部门窃听电话是一个公开的秘密。

It's an open secret that the security service bugged telephones.

《柯林斯英汉双解大词典》

so in some sense it's safer, it avoids the 0, although I mean it's true it avoids the 0 but it also doesn't get the 5 and the 4.

某些情况下选下是比较安全的,因为他避免了0收益,我的意思是它的确避免了0收益,但选它也得不到5和4这连个最大收益

耶鲁公开课 - 博弈论课程节选

You can brute force it and unfortunately, the so-called Caesar cipher is not very secure because if you assume, for our purposes in English alphabet with 26 characters, say all lowercase for all uppercase, my God, you only have to try like 24, 25, 26 possible rotations until you can figure out what his secret message is.

你可以强行解密但是不幸地是，所谓的凯撒密码不是很安全的,因为如果假设，对于我们的26个字符的字母表,指明所有的小写为大写，我的天，你只要试24，25次，26次就可以解答出,密文的内容。

哈佛公开课 - 计算机科学课程节选

Even when the president first came into the office he is always careful to make sure he was always well briefed, meet regularly with his national security team, with his intelligence briefers, on a regular basis.

即使是总统从一开始,走进办公室,他总会很小心地确保,他有个良好的情况简介，和他的安全小组见面，和情报简报员见面，这些都是定期的。

普林斯顿公开课 - 国际座谈会课程节选