Pretty good encryption

Abstract

The use of codes and other methods of concealing the contents of messages is as old as recorded information. With the advent of computer communication, the need for a method of ensuring secure communication over insecure channels, such as the Internet, has seen an increased demand for good cryptography. However, the recent avail ability of public domain public-key encryption software, such as Philip R. Zimmermann's Pretty Good Privacy (PGP), has been described as 'letting the cryptographic genie out of the bottle', and has raised issues of national communication policy and personal privacy. In the USA, the government's Clipper encryption chip initiative sought to implement a key escrow system which would enable law enforcement agencies to wiretap all digital communi cation. Civil liberty opponents of key escrow systems argue that they will not affect criminals, and fear that they can only be made effective by banning the use of alternative encryption systems, such as PGP. Methods for obtaining and using PGP to encrypt and decrypt e-mail messages are described.