Answer:
Encapsulating Security Payload (ESP)
Explanation:
Encapsulating Security Payload is also known as ESP, it is a protocol that exists within IPSec, it helps in determining the authentication, integrity and how confidential network pack data / Payload in IPV4 and IPV6 networks are.
ESP supplies messages /Payload encipher, it also helps in authenticating Payload as well as where it originated from in the IPSec protocol suite.