
456 Chapter 11 • Developing Security-Enabled Applications
Digital signatures are one way of ensuring that a message gets to its
recipient safely.The other methods discussed in the following sections,
PGP and S/MIME, use encryption algorithms instead of hashing algo-
rithms to perform their duties.
Pretty Good Privacy
Pretty Good Privacy (PGP) is pretty much a standard for e-mail security,
used by individuals and corporations alike. Phillip R. Zimmermann
developed PGP in 1991, and it has since taken off to become the most
widely used e-mail cryptography method. PGP can be used to not only
encrypt and decrypt e-mails, but it can also be used to encrypt ...