What is the purpose of using salt in cryptographic hashing?

The purpose of using salt in cryptographic hashing is to increase the complexity of generated hashes. When a salt is added to a password before hashing, it introduces randomness that makes each hash unique, even if the same password is used by different users. This uniqueness helps to protect against precomputed attacks, such as rainbow table attacks, which rely on having a set list of hashes for common passwords. By using a salt, even the same password will produce different hashes when salted differently, thereby greatly enhancing the security of stored passwords.

Other options do not correctly reflect the main function of salt in this context. For instance, while enhancing data transmission speeds or enabling reversible encryption might be desirable in other scenarios, these are not relevant to the hashing process itself. Hashing is meant to be a one-way function, providing security by making it computationally infeasible to retrieve the original data from the hash. Thus, the main advantage gained from using a salt relates specifically to the increased complexity and uniqueness of the hashes generated.