IP Security (IPsec)

An Institute of Electrical and Electronic Engineers (IEEE) standard, Request For Comments (RFC) 2411, protocol that provides security capabilities at the Internet Protocol (IP) layer of communications. IPsecs key management protocol is used to negotiate the secret keys that protect Virtual Private Network (VPN) communications, and the level and type of security protections that will characterize the VPN. The most widely used key management protocol is the Internet Key Exchange (IKE) protocol.