Abstract: A method and system for securing keys in which all key blanks are assigned a unique serial number and access to uncut key blanks is restricted to authorized distributors and keycutters, through whom the current location of uncut serialized key blanks is tracked in a remotely accessible database to whom only authorized individuals have access. The database stores the access code of all uncut serialized key blanks and, when a key is cut from a serialized key, an access code is associated in the database with the cut serialized key. Duplicate copies of serialized keys can be created only upon presentation of the serialized key and the access code associated in the database with the serialized key in response to verification of the association by the database. No identifying information relating to the location of a lock operable by a particular serialized key or to an owner of the serialized key is associated in the database with the serialized key.

Abstract: A method of assigning change keys and master keys in a master key system using a 6 pin cylinder with 5 bittings based on an 8×8 checkerboard and pieces ¼, 1, 4, 16 squares in size representing 16, 64, 256 and 1024 change keys with a master key bitting combination available for each piece which would operate all the change keys assigned to that piece. A first alternate embodiment uses an array of (b−1)(p−3) elements (b being the number of bittings and p being the number pins used for master keying), each array element representing (b−1)3 change keys. The array being repeatedly divided into subarrays of (b−1)(p−x) elements, where x=4, 5, 6, . . . , p−1. Instead of assigning the change keys to a checkerboard piece, the change keys are assigned to a subarray representing at least the number of change keys.