Internet Protocol Security (IPSec)
Internet Protocol Security (IPSec) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet in a data stream. IPSec is used in virtual private networks (VPNs) to ensure secure communication over untrusted networks like the internet. It operates at the network layer, allowing it to secure all application traffic over an IP network. Features include access control, connectionless integrity, data origin authentication, and confidentiality.