"One of the best ways to protect sensitive computer data like
credit card numbers and social security information is to use
encryption software. Encryption software executes an algorithm that
is designed to encrypt data in such a way that it cannot be
recovered (decrypted) without access to the key. It is a main
component of all aspects of file protection and computer
communication. Files on hard drives and other removable media,
email messages, and packets sent over computer networks can be made
secure by encryption software.
"For those of you who are interested, here's a list of
well-known free and open source encryption software for Linux:"