P-2602H(W)(L)-DxA Series User’s Guide
CH A P T E R 16
Introduction to IPSec
This chapter introduces the basics of IPSec VPNs.
16.1 VPN Overview
A VPN (Virtual Private Network) provides secure communications between sites without the expense of leased
16.1.1 IPSec
Internet Protocol Security (IPSec) is a
16.1.2 Security Association
A Security Association (SA) is a contract between two parties indicating what security parameters, such as keys and algorithms they will use.
16.1.3 Other Terminology
16.1.3.1 Encryption
Encryption is a mathematical operation that transforms data from "plaintext" (readable) to "ciphertext" (scrambled text) using a "key". The key and clear text are processed by the encryption operation, which leads to the data scrambling that makes encryption secure. Decryption is the opposite of encryption: it is a mathematical operation that transforms “ciphertext” to plaintext. Decryption also requires a key.
Chapter 16 Introduction to IPSec | 215 |