Encapsulating Security Payload (ESP)
Definition - What does Encapsulating Security Payload (ESP) mean?
An Encapsulating Security Payload (ESP) is a protocol within the IPSec for providing authentication, integrity and confidentially of network packets data/payload in IPv4 and IPv6 networks. ESP provides message/payload encryption and the authentication of a payload and its origin within the IPSec protocol suite.
Techopedia explains Encapsulating Security Payload (ESP)
An Encapsulating Security Payload is primarily designed to provide encryption, authentication and protection services for the data or payload that is being transferred in an IP network. ESP doesn’t protect the packet header; however, in a tunnel mode if the entire packet is encapsulated within another packet as a payload/data packet, it can encrypt the entire packet residing inside another packet. Typically, in an IP network packet, the ESP header is placed after the IP header. The components of an ESP header include sequence number, payload data, padding, next header, an integrity check and sequenced numbers.