From Rosetta Code

Tasks in this category have to do with data encryption (or decryption) using various algorithms.

Note that encryption is not the same as a checksum.

With encryption, the derived data carries an encrypted form of the original data, and can be manipulated to recreate the original input.

A checksum is simply a sequence of characters (usually just a few characters in length) that cannot be converted back to the original form (because more than one input can have the same checksum).