But I know today in my math class, we were learning about the guys who created RSA Public Key Cryptography.

但是今天的数学课上，我们在学习RSA公钥加密算法的创始人。

积极参与俱乐部活动 - SpeakingMax英语口语达人

The number that you choose to rotate your letters by is what we call in cryptography, a key.

你选择的旋转字母的数量,就是所谓的加密学，一个密钥。

哈佛公开课 - 计算机科学课程节选