Chapter 5. Fundamentals of VPN Technology and Cryptography

This chapter covers the following topics:

Understanding VPNs and why we use them

Cryptography basic components

Public key infrastructure

Putting the pieces of PKI to work

Many organizations deploy virtual private networks (VPN) to provide data integrity, authentication, and data encryption to ensure confidentiality of the packets sent over an unprotected network or the Internet. VPNs are designed to avoid the cost of unnecessary leased lines. Understanding why VPNs are important and the underlying building blocks that make them work so well is the focus of this chapter.