Security Encyclopedia

Internet Security (IPsec)

Internet Security (IPsec) is a suite of open standard protocols that secure connections over the Internet Protocol (IP), meaning the underlying technology that makes the internet possible. 

IPsec established mutual authentication between pairs of hosts, protecting data flows, and it is used in a Virtual Private Network (VPN). These pairs can be hosts (e.g. machines or applications), security gateways (called networks), or security gateways and hosts (network-host). 

IPsec consists of Authentication Headers (AH) that provide no connection, but contain data origin and data integrity information; Encapsulating Security Payloads (ESP) covering confidentiality and data-origin authentication; and Security Associations (SA), or a bundle of algorithms that facilitate the processes covered by AH and ESP.

Avaya, Barracuda SSL VPN gateway, and Check Point Software Technologies are examples of providers that focus on securing remote networks.


“The underlying protocol of the internet, IP, does not secure connections between people on their devices and networks. IPsec, however, is the bundle of protocols that makes these connections secure and private if wanted. That’s why VPNs use IPsec.”