Which of the following is an IPSec protocol that provides confidentiality with authentication, integrity, and anti-replay?

A.
PEAP

B.
ESP

C.
EAP-TLS

D.
PPP

Explanation:
Encapsulating Security Payload (ESP) is an IPSec protocol that provides confidentiality with authentication, integrity, and anti-replay. ESP can be used alone in combination with Authentication Header (AH). ESP can also be used nested with the Layer Two Tunneling Protocol (L2TP). Normally, ESP does not sign the entire packet unless it is being tunneled. Typically, only the data payload is protected, not the IP header.
Answer option A is incorrect. The Protected Extensible Authentication Protocol, also known as Protected EAP or simply PEAP, is a protocol that encapsulates EAP within an encrypted and authenticated Transport Layer Security (TLS) tunnel. The purpose was to correct deficiencies in EAP; EAP assumed a protected communication channel, such as that provided by physical security. Answer option C is incorrect. EAP-Transport Layer Security (EAP-TLS) is an authentication protocol created by Microsoft. It is considered the most secure EAP standard and is supported by all manufacturers of wireless LAN software and hardware. EAP-TLS is used in conjunction with Public Key Infrastructure (PKI) and computer certificate, user certificate and smart card. A hacker cannot break into EAP-TLS enabled systems using only a password. He still needs to have the client- side private key.
Answer option D is incorrect. The Point-to-Point Protocol, or PPP, is a data link protocol commonly used to establish a direct connection between two networking nodes. It can provide connection authentication, transmission encryption privacy, and compression. PPP is commonly used as a data link layer protocol for connection over synchronous and asynchronous circuits, where it has largely superseded the older, non-standard Serial Line Internet Protocol (SLIP) and telephone company mandated standards (such as Link Access Protocol, Balanced (LAPB) in the X.25 protocol suite). PPP was designed to work with numerous network layer protocols, including Internet Protocol (IP), Novell’s Internetwork Packet Exchange (IPX), NBF, and AppleTalk.