The invention relates to a locking system, for providing authorization to access and drive a motor vehicle. The locking system has a first device, which is a control device for unlocking and locking the car doors, the ignition lock, the steering wheel lock, etc. Additionally, the locking system has a second device, which is an electronic key or an identifier. The two devices have transmission means and/or receiving means for electromagnetic signals with frequencies ν lying in a frequency band between two cut-off frequencies νa, νb. At least one of the signals, transmitted between the devices, is a coded operating signal for authenticating the second device. The actual frequency νi with which the transmission means of the second device is operated is stored in a storage means of the first device.