Abstract: An automatic system for identifying an authorized key utilized to lock and unlock a door lock and to record pertinent data attendant thereto is disclosed herein having a key sensing mechanism incorporated into a lock that operates a switch circuit to generate a key identification signal. A control circuit receives the signal as well as time and date information and introduces this data to a printer for producing a visual record of the door lock transaction. The authorized key is coded not only to lock and unlock the door lock but includes a plurality of identification number codes along a given length.