3. Cryptography Overview

3.1 Introduction

Cryptography is a vast and difficult field that we cannot hope to cover in this book. Nevertheless, an understanding of the basics and an appreciation of some of the subtleties of cryptography are necessary for an understanding of what is to follow. Fortunately, just as with TCP/IP, several excellent texts are available for those who wish to delve deeper into its mysteries—see [Schneier 1996], [Ferguson and Schneier 2003], and [Menezes, Oorschot, and Vanstone 1996], for example.

In this chapter, we are concerned mainly with three major subjects:

  1. Encryption/decryption
  2. Message authentication codes
  3. Digital signatures

Along the way, we shall also examine Diffie-Hellman key exchange and the use of ...

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