What is the main function of Authentication Headers (AH) in network security?

Authentication Headers (AH) serve a primary function in confirming the authenticity and integrity of the data being transmitted over the network. This mechanism is crucial in preventing unauthorized parties from engaging in activities such as data tampering or spoofing.

When a data packet is sent with an Authentication Header, it includes a cryptographic checksum that is calculated from the data and a shared secret key. This allows the recipient to verify both the integrity of the received data and its origin. If the data has been altered in transit, the checksum will not match, indicating a potential security breach.

AH does not alter the data being transmitted; rather, it adds an authentication header that provides a way to confirm that the data is from a legitimate source and has not been changed. This focus on ensuring the origin of the data without making modifications is what distinguishes the functionality of AH in network security protocols. Thus, the correct choice highlights the role of AH in providing identity verification and confirming data integrity without altering the original content during transmission.