Improvements in or relating to security systems

The invention consists of attaching or embedding a "TIRIS" transponder (or other RF or IR or barcode or other identifying device) physically into the center of the proposed DVD disk. Within the memory of the transponder, both a predetermined address and a code word are preprogrammed into the transponder at the manufacturing level of the media product. The media player not only comprises functionality to play the disk, but also comprises the functionality to transmit an interrogation signal to the transponder, and then to receive the transponder response signal. Therefore, once a disk is input to a media player, the interrogation portion of the media player transmits an interrogation signal to the transponder located on the disk. Thus once empowered with the interrogation signal, the transponder accesses the predetermined address and the code word from it's memory. Then the transponder transmits both the address and the code word to the interrogator, located within the media player, and the player accesses the particular address Iocation on the disk. The media player only plays if there is a match between the read data-word and received code word. The comparison can occur within the interrogation portion of the media player or within the media player itself.