What is a salt in cryptographic terms?

In cryptographic terms, a salt is specifically understood as random bits that are intermixed with a hash. When hashing passwords or any sensitive data, a salt is added to the input before the hashing process. This practice ensures that even if two users have the same password, the resulting hash will be different because each password will be combined with its unique salt.

Using a salt serves multiple purposes: it protects against rainbow table attacks, where an attacker precomputes hashes for common passwords, and it ensures that each instance of a password hash is unique, making it significantly more challenging for attackers to crack the hashes.

The other options do not accurately represent the function of a salt. For instance, key whitening refers to techniques used to enhance the security of a cryptographic key. Random bits intermixed with a symmetric cipher describes a method of increasing the randomness in symmetric encryption rather than focusing on the unique hashing process involving salts. Lastly, key rotation is a policy strategy used in key management to regularly update cryptographic keys, which is unrelated to the concept of salts in hashing.