Which term refers to a value derived from a set of data that helps verify data integrity and is used in digital signatures?

Which term refers to a value derived from a set of data that helps verify data integrity and is used in digital signatures?

• A. Hash
• B. Salt
• C. Key
• D. Certificate

Answer: (A)

Hashes are derived from data to create a compact fingerprint that can be recomputed to verify integrity. When a message is signed, a hash of the message is produced and that hash is signed with a private key. The recipient then rehashes the received data and verifies that the signature corresponds to this hash; if the data were altered, the hash would change and the signature wouldn’t match, signaling tampering. This combination of a fixed-size, deterministic digest with digital signatures is what provides data integrity and authenticity. Salt is used to add randomness to input before hashing to defend against precomputed attacks, not to verify integrity or sign data. A key is the secret used in encryption or signing, not the derived value that represents the data itself. A certificate binds a public key to an identity and helps establish trust, but it is not the value derived from the data used for integrity checks or signature creation.

Hashes are derived from data to create a compact fingerprint that can be recomputed to verify integrity. When a message is signed, a hash of the message is produced and that hash is signed with a private key. The recipient then rehashes the received data and verifies that the signature corresponds to this hash; if the data were altered, the hash would change and the signature wouldn’t match, signaling tampering. This combination of a fixed-size, deterministic digest with digital signatures is what provides data integrity and authenticity.

Salt is used to add randomness to input before hashing to defend against precomputed attacks, not to verify integrity or sign data. A key is the secret used in encryption or signing, not the derived value that represents the data itself. A certificate binds a public key to an identity and helps establish trust, but it is not the value derived from the data used for integrity checks or signature creation.