IPSec is a standard suite of protocols that provides security at layer 3, or the IP layer, and was designed to provide the following security features when transferring packets across a network:
IPSec contains many elements, which will be discussed in the following sections.
Encapsulating Security Payload (ESP) provides authentication, integrity, and confidentiality, which help protect against data tampering and provide message content protection. IPSec implements industry standard algorithms, such as SHA and MD5, to produce a unique identifier for each packet that cannot be forged. These "fingerprints" allow the receiver to determine whether a packet has been tampered with. Packets that are not authenticated...