This chapter covered the basics of the various mechanics (Confidentiality, Integrity, Availability, Key Management, and Encryption) and how they are achieved using the basic mechanisms of cryptography, various protocols, and methods. In later chapters, you will learn about how these basic primitives are employed in the realm of wireless security, the various vulnerabilities because of the way the mechanics are combined, and the advances to mitigate the vulnerabilities. The authors would like to thank Cisco Press and Merike Kaeo for the materials from the excellent Cisco Press book, Designing Network Security.