ccrypt is a tool for encrypting and decrypting files and streams. It is based on the Rijndael block cipher, a version of which is also used in the Advanced Encryption Standard (AES).
The algorithm provided by ccrypt is not symmetric. The most common way to invoke ccrypt is via the commands ccencrypt and ccdecrypt. There is also a ccat command for decrypting a file directly to the terminal, thus reducing the likelihood of leaving temporary plaintext files around. In addition, there is a compatibility mode for decrypting legacy files from the ancient Unix crypt(1) command. An emacs mode is also supplied for editing encrypted text files.