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IPSec Overview Part One: General IPSec Standards

Article Description

Virtual Private Networks (VPNs) are becoming required expertise for network and security engineers, and IPSec is the most commonly used protocol when implementing VPNs. In this first article of a five-part series on the Cisco implementation of IPSec, Andrew Mason delves into the components that make up the IPSec protocol suite.

Diffie-Hellman (D-H)

Diffie-Hellman (D-H) is a public-key cryptography protocol. It allows two parties to establish a shared secret key used by encryption algorithms (DES or MD5, for example) over an insecure communications channel. D-H is used within IKE (described later in this article) to establish session keys. 768-bit and 1024-bit D-H groups are supported in the Cisco routers and PIX Firewall. The 1024-bit group is more secure.

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