SECUR Exam Cram™ 2 (Exam 642-501)

Framework of IPSec

Cryptography in plain English is the art of taking data, jumbling it up so it looks nothing like its original form, and being able to put it back in its original form again at some future time. To jumble up data, we take our plaintext data and encrypt it using a special value called a key. This process produces our jumbled-up data, called ciphertext. Ciphertext can travel a public medium and be sniffed by an attacker. The attacker, however, without the correct algorithm and key can in no way decipher the message. So right away, we know that both ends of a secure link must know two very important items. They must know the encrypting algorithm as well as the key used to encrypt and decrypt the data.

A problem these two parties ...