Overview
GnuPG is a publicly available encryption scheme that uses the "public key" approach. With GnuPG, messages are encrypted using a "public key" however, they can only be decrypted by a "private key", which is retained by the intended recipient of the message. If you are unfamiliar with GnuPG Keys, visit the WikiPedia web site on GNU Privacy Guard at http://en.wikipedia.org/wiki/Gpg.