salt

In password protection, salt is a random string of data used to modify a password hash. Salt can be added to the hash to prevent a collision by uniquely identifying a user's password, even if another user in the system has selected the same password. Salt can also be added to make it more difficult for an attacker to break into a system by using password hash-matching strategies because adding salt to a password hash prevents an attacker from testing known dictionary words across the entire system.