Symmetric Key Cryptography

Abstract

Cryptography is the study of how to mathematically encode and decode messages. The objective of this chapter and the next is to show you how to use cryptography as a tool to achieve some of the security goals we discussed in Chapter 1. A cryptographic primitive is an algorithm that can be used to, for example, encode or decode a message. In this chapter and the next, you’ll see how to use cryptographic primitives to achieve authentication, confidentiality, and message integrity.