Which IPSec sub-protocol provides encryption and authentication of the header and payload of a data packet?

Which IPSec sub-protocol provides encryption and authentication of the header and payload of a data packet?

• A. Authentication Header (AH)
• B. Encapsulating Security Payload (ESP)
• C. Internet Key Exchange (IKE)
• D. Transport Layer Security (TLS)

Answer: (B)

In IPSec, the sub-protocol that provides confidentiality (encryption) along with integrity/authentication for the data is Encapsulating Security Payload. It encrypts the payload to keep it confidential and can also provide authentication of the encrypted data. When used in tunnel mode, it protects the entire original IP packet, including its header, by encapsulating and encrypting it inside the ESP payload, delivering both header and payload protection. Authentication Header offers integrity and authenticity but does not encrypt the payload. Internet Key Exchange handles negotiating keys and security associations, not data protection. Transport Layer Security is a separate protocol for end-to-end encryption at the transport layer, not IPSec.

In IPSec, the sub-protocol that provides confidentiality (encryption) along with integrity/authentication for the data is Encapsulating Security Payload. It encrypts the payload to keep it confidential and can also provide authentication of the encrypted data. When used in tunnel mode, it protects the entire original IP packet, including its header, by encapsulating and encrypting it inside the ESP payload, delivering both header and payload protection.

Authentication Header offers integrity and authenticity but does not encrypt the payload. Internet Key Exchange handles negotiating keys and security associations, not data protection. Transport Layer Security is a separate protocol for end-to-end encryption at the transport layer, not IPSec.