An electronic lock is actuatable by an electronic key. The key comprises a plurality of different resistive elements and a signal generator having a plurality of different timing periods. The key further has a signal transmitter. The electronic lock means comprises a lock and a signal receiver. The lock further has a comparator which includes a plurality of different resistive means. The comparator compares each consecutive timing period with the timing period determined by one of the resistive means. The lock further has an activating element for the lock in the event the consecutive timing periods of said signal match the timing periods determined by the plurality of resistive means.