DISTRIBUTED DATABASE SECURITY SYSTEM

摘要

An electronic security system includes a controller for controlling access to a location through activation of a lock mechanism in response to coded data and command instructions read from a key or card containing an electronic memory. The key memory data includes information specific to the keyholder which is decoded and acted upon by the controller. The controller memory can be reduced in size while still allowing the use of a large number of keys, by distributing a larger amount of data to the key memories. The controller is also capable of writing and altering key memory data in real time to control the subsequent use of the key.