High Quality Content by WIKIPEDIA articles! Rekeying normally refers to the ability to change a lock so that a different key may operate it. Rekeying is done when a lock owner may be concerned that unauthorized persons have keys to the lock, so the lock may be altered by a locksmith so that only new keys will work. Rekeying is a relatively simple a process of changing the tumbler or wafer configuration of the lock so a new key will function while the old one will not. Rekeying may be done without replacement of the entire lock.