ccrypt is a command line utility for encrypting and decrypting files and streams. It was designed as a replacement for the standard Unix crypt utility, which is notorious for using a very weak encryption algorithm. ccrypt is based on the Rijndael cipher, which is the U.S. government's chosen candidate for the Advanced Encryption Standard (AES). This cipher is believed to provide very strong security. A compatibility mode is included for decrypting legacy "unix crypt" files.
Unlike unix crypt, the algorithm provided by ccrypt is not symmetric, i.e., one must specify whether to encrypt or decrypt. 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 unix crypt files. An emacs mode is also supplied for editing encrypted text files.
Continue Reading... Unlike unix crypt, the algorithm provided by ccrypt is not symmetric, i.e., one must specify whether to encrypt or decrypt. 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 unix crypt files. An emacs mode is also supplied for editing encrypted text files.
source:http://linuxpoison.blogspot.com/2011/04/135781677512773.html