2.7 Summary

In this chapter, we introduced the most important cryptographic definitions and described the main cryptographic goals, namely confidentiality, integrity, and authentication. We showed that combining these goals into the CIA triad allows Alice and Bob to establish a secure channel in the presence of both passive and active attackers.

In the next chapter, you will learn what a cryptographic key – a secret shared by Alice and Bob – is and why it is needed to establish a secure channel. In particular, you will learn why Alice and Bob should update keys frequently, and how long the key should be so Alice and Bob can communicate securely.