What Is the Purpose of “Salting” a Password Hash?

Salting is the process of adding a unique, random string (the salt) to a password before it is hashed. This prevents attackers from using pre-computed rainbow tables to quickly crack password hashes.

Even if two users have the same password, the unique salt ensures their stored hashes are different. It forces an attacker to perform a brute-force attack on each individual hash, significantly increasing the computational cost.