(Which component is used to verify the integrity of a message?

HMAC (Hash-based Message Authentication Code) is a standard mechanism used to verify both integrity and authenticity of a message when two parties share a secret key. It combines a cryptographic hash function (such as SHA-256) with a secret key in a structured way that resists common attacks on naïve keyed-hash constructions. The sender computes an HMAC tag over the message and transmits the message plus tag. The receiver recomputes the HMAC using the same shared secret key and compares the result; if the tag matches, the receiver can be confident the message was not modified in transit and that it came from someone who knows the shared key. AES is an encryption algorithm primarily providing confidentiality; it can provide integrity only when used in authenticated modes (e.g., GCM) but “AES” alone is not the integrity component. An IV helps randomize encryption but does not validate integrity. TKIP is a legacy WLAN protocol component, not the general integrity verifier. Therefore, the correct component for verifying message integrity among the options is HMAC.