Summary Explanation of symmetric (single key) and asymmetric (public/private key) encryption, GnuPG (GPG) basics. Reference Materials http://www.gnupg.org/documentation/index.en.html – GnuPG Documentation Introduction to Cryptography Basic Principles ftp://ftp.pgpi.org/pub/pgp/6.5/docs/english/IntroToCrypto.pdf source