When you buy a drug, you scratch the panel, you send a text message with the number that you see, and you get a response instantly at the counter if the drug is genuine or fake."

VOA: standard.2010.06.07

It's a secret number so that if Julius Caesar scrambled his message with the key 13, well, then the recipient had better know what that number is or realistically, -- and this is why it's kind of hard to buy -- into some of these age old algorithms, -- what would an alternative approach be to figuring out Julius Caesar's messages to his generals if he didn't know that secret number was 13?

它是一个机密的数字，以至于,如果凯撒大帝使用密钥13加密了它的消息，然后接收者最好知道那个数字是什么,实际上--这就是为什么很难,破解这些古老的算法-,有什么变换方法使凯撒大帝的将军,可以解密凯撒大帝的消息，如果他不知道,那个机密数字是13呢？

哈佛公开课 - 计算机科学课程节选

Luciani says UNICEF is working closely with a number of youth groups in Guinea Bissau because those organizations are often more effective at getting the message out to young people who might ignore more traditional public health campaigns.

VOA: standard.2009.04.24