Official PGP page The software that made cyberspace great, and to this day causes a great gnashing of teeth at various law enforcement agencies. PGP scrambles messages so that only the intended recipient can read them.
Official PGPfone home page A step beyond PGP, PGPfone renders your voice communications untappable.
International PGP page This site offers a slightly different version of the encryption software.
Cypherpunk page One of many excellent cypherpunk pages, it offers great information and links on the art of keeping your private information just that.