PGP: 2.6 Pretty Good Privacy (Book, November 1994)

PGP is a freely available encryption program that protects the privacy of files and electronic mail. It uses powerful public key cryptography and works on virtually every platform. This book is both a readable technical user's guide and a fascinating behind-the-scenes look at cryptography and privacy. It describes how to use PGP and provides background on cryptography, PGP's history, battles over public key cryptography patents and U.S. government export restrictions, and public debates about privacy and free speech.