IPsec - technical definition

(IP SECurity) A security protocol from the IETF that provides authentication and encryption over the Internet. Unlike SSL, which provides services at layer 4 and secures two applications, IPsec works at layer 3 and secures everything in the network. Also unlike SSL, which is typically built into the Web browser, IPsec requires a client installation. IPsec can access both Web and non-Web applications, whereas SSL requires workarounds for non-Web access such as file sharing and backup.

IPsec is supported by IPv6. Since IPsec was designed for the IP protocol, it has wide industry support and is expected to become the standard for virtual private networks (VPNs) on the Internet. See VPN, IKE, IPv6 and security protocol.