the process of changing electronic information or signals into a secret code (= system of letters, numbers, or symbols) that people cannot understand or use without special equipment

The records were stored using protective encryption. 这些记录是使用保护性加密存储的。

The company's encryption software allows secure credit card transactions over the internet. 该公司的加密软件允许通过互联网进行安全的信用卡交易。