What term describes a mathematical function that creates a value from data to verify its integrity?

• A. Encryption
• B. Hash
• C. Decryption
• D. Salting

Answer: (B)

A hash function is a mathematical function that takes data and produces a fixed-length value, the hash, which serves as a fingerprint of the data. This is used to verify integrity because the same data always yields the same hash, and even a tiny change to the data results in a drastically different hash. To check integrity, you compute the hash of the original data and compare it to the hash computed later; if they match, the data is likely unchanged. This is different from encryption, which transforms data for confidentiality using keys, and from decryption, which reverses encryption. Salting adds extra data before hashing to strengthen security in certain contexts, but the value created to verify integrity is the hash itself.