Firewalls and Internet Security: Repelling the Wily Hacker, Second Edition

Appendix A. An Introduction to Cryptography

Cryptography is a complex and highly mathematical art and science. The basic building blocks are easy enough to understand; we caution you, however, that there are very many subtle interactions when actually using cryptosystems. This appendix is the barest introduction; even elementary cryptography cannot be covered fully here. Readers desiring a more complete treatment should consult any of a number of standard references, such as [Schneier, 1996], [Stinson, 1995], or [Menezes et al., 1997]. See [Kahn, 1996] for the history of cryptography.

Selecting an encryption system is comparatively easy; actually using one is less so. That is the domain of cryptographic protocols, a field that is even more strewn ...