storedHash

storedHash refers to a cryptographic hash value that a system saves in a data store to represent a secret, typically a user password, rather than storing the secret itself. The stored value enables verification of the secret during authentication without exposing it in plaintext.

In a typical authentication flow, a user enters a password. The system retrieves the corresponding storedHash and the parameters used to compute it (such as the salt and iteration count). The system then computes a hash of the provided password using the same algorithm and parameters and compares it to the storedHash. A match authenticates the user.

To protect against precomputed attacks, a random salt is usually used and stored with the hash. Strong hash functions and iteration counts slow down guessing attempts. Common modern choices include bcrypt, scrypt, Argon2, and PBKDF2.

Security considerations: If the stored hash is stolen, an attacker can attempt offline guessing, but effectiveness depends on the hash function, salt, and iteration count. Best practices include per-user salts, high work factor, using proven password hashing algorithms, and rotating or updating parameters if a breach occurs.

In broader use, the term storedHash can also refer to any cryptographic hash retained to verify data integrity or to authenticate tokens, but in computing and security contexts it most often concerns password storage.