Information service method, information service unit, recording or reproducing controlling method, and recording and/or reproducing unit

A reproducing controlling system, comprising:

• receiving circuitry, at a client device, that receives identification information unique to a data recording medium from the data recording medium;
• an interface, at the client device, that transmits the received identification information and information that represents a use mode of the data recording medium to a server, wherein the server correlatively stores the identification information and management information corresponding to the data recording medium, and updates the management information when the transmitted identification information and the information that represents a use mode of the data recording medium are received from the client device, and that receives, from the server, key data and license information generated in accordance with the updated management information, wherein the key data controls whether to reproduce content data recorded on the data recording medium or to record the content data recorded on the data recording medium;
• and
• a processor, at the client device, that controls whether to reproduce the content data or to record the content data based on the received key data.

A client device comprising:

• receiving circuitry that receives identification information unique to a data recording medium from the data recording medium;
• an interface that transmits the received identification information and information that represents a use mode of the data recording medium to a server, wherein the server correlatively stores the identification information and management information corresponding to the data recording medium, and updates the management information when the transmitted identification information and the information that represents a use mode of the data recording medium are received from the client device, and that receives, from the server, key data and license information generated in accordance with the updated management information, wherein the key data controls whether to reproduce content data recorded on the data recording medium or to record the content data recorded on the data recording medium;
• and
• a processor controls whether to reproduce the content data or to record the content data based on the received key data.

A non-transitory computer-readable recording medium including computer program instructions, which when executed by a client device, cause the client device to perform a method comprising:

• receiving identification information unique to a data recording medium from the data recording medium;
• transmitting the received identification information and information that represents a use mode of the data recording medium to a server, wherein the server correlatively stores the identification information and management information corresponding to the data recording medium, and updates the management information when the transmitted identification information and the information that represents a use mode of the data recording medium are received from the client device;
• receiving key data and license information generated in accordance with the updated management information from the server, wherein the key data controls whether to reproduce content data recorded on the data recording medium or to record the content data recorded on the data recording medium;
• and
• controlling whether to reproduce the content data or to record the content data based on the received key data.