A liquid crystal display device includes an LED backlighting unit and a liquid crystal display panel disposed on the backlighting unit. The method also includes defining a heavily doped region at a surface of the semiconducting substrate in at least one area of the semiconducting substrate, where the heavily doped region includes a heavily doped layer having a doping concentration greater than a doping concentration of the semiconducting substrate. A controller first determines whether a valid authentication code is received from a passive signaling device.