Abstract: Safety mechanism for locks (electronic lock) comprising a pick-up performing the function of a key and a sensor performing the function of a lock part. The pick-up is provided with a pre-determined surface arrangement of magnetically permeable, preferably inactive material in the form of soft-iron pins forming exciting elements, which forms a code. For detecting the code of the pick-up, the sensor is provided with an arrangement of sensor elements in a surface matrix of the same geometrical extension, which sensor elements can be varied as to their ohmic resistance by a change in the distribution of the magnetic field lines and take the form of magnetically controllable magneto-resistors. The magneto-resistors are set up, preferably, in the manner of an integrated circuit.