Abstract: A recording disc has a lead-in area and a data area. A scrambled version of a SID code word is read out from the lead-in area of the disc. The SID code word represents a producer of the disc. The readout scrambled version is de-scrambled to recover the SID code word. The recovered SID code word is collated with reference SID code words to decide whether or not the disc is legitimate. Main information is read out from the data area of the disc when it is decided that the disc is legitimate. Readout of the main information from the data area of the disc is inhibited when it is decided that the disc is not legitimate.

Abstract: A recording disc has a lead-in area and a data area. A scrambled version of a SID code word is read out from the lead-in area of the disc. The SID code word represents a producer of the disc. The readout scrambled version is de-scrambled to recover the SID code word. The recovered SID code word is collated with reference SID code words to decide whether or not the disc is legitimate. Main information is read out from the data area of the disc when it is decided that the disc is legitimate. Readout of the main information from the data area of the disc is inhibited when it is decided that the disc is not legitimate.

Abstract: An audio-contents demo system includes a WWW server, a system server, and a mobile telephone device. The WWW server stores information representing audio contents. The system server can be connected with the WWW server via the Internet. The mobile telephone device can be connected with the system server via either a telephone-Internet connection service or a public telephone network. The mobile telephone device sends a signal of a demo-request toward the system server via the telephone-Internet connection service. In response to the demo-request signal sent from the mobile telephone device, the system server accesses the WWW server and takes out a piece of the audio-contents information from the WWW server via the Internet. The audio-contents information piece corresponds to the demo-request signal sent from the mobile telephone device. The system server sends the audio-contents information piece toward the mobile telephone device via the public telephone network.

Abstract: A recording disc has a lead-in area and a data area. A scrambled version of a SID code word is read out from the lead-in area of the disc. The SID code word represents a producer of the disc. The readout scrambled version is de-scrambled to recover the SID code word. The recovered SID code word is collated with reference SID code words to decide whether or not the disc is legitimate. Main information is read out from the data area of the disc when it is decided that the disc is legitimate. Readout of the main information from the data area of the disc is inhibited when it is decided that the disc is not legitimate.