Abstract: An electronic door locking apparatus includes a key containing a first memory for storing a first code, and an electronic lock having a receptacle for receiving and reading the first code, a locking mechanism actuatable to a locking or unlocking condition, and a control system for controlling the locking mechanism in response to the insertion of a key into the receptacle. The control system includes a second memory for storing a second code, detectors for detecting whether the door is open or closed, a New-Code control member actuatable by the user when a new code is to be generated, and a Copy-Code control member actuable by the user when the code in the control system is to be copied into the memory of another key inserted into the receptacle.