Patent ID: 8584249

Claim:
A system for preventing unauthorized play of digital content, comprising: a distributing recording medium selected from a general recording medium group consisting of a CD and a DVD, in which a content file having partial header information and a data body is recorded, wherein an omitted part of the header information is absent from the distributing recording medium, and wherein the omitted part of the header information is needed by a digital content playing device to play the data body; a bank or credit card company communicatively coupled to the Internet with a communication line; a management unit communicatively coupled to the Internet with the communication line, the management unit configured to manage use of the content file on the distributing recording medium and capable of transferring a piece of data via the communication line, wherein the communication line is configured to communicate the piece of data after a charge is collected from the bank or credit card company, and wherein the piece of data includes the omitted part of the header information; and a digital content playing device communicatively coupled to the Internet with the communication line, the digital content playing device configured to play the content file on the distributing recording medium and having a function of communicating via the communication line with the management unit; wherein in response to detecting a request to play the content file under authentication and charging conditions input by a user to the digital content playing device, the digital content playing device transfers the request via the communication line to the management unit, the management unit checks authentication and charging of the user related to the request before transferring the piece of data via the communication line to the digital content playing device, and the digital content playing device uses the partial header information on the distributing recording medium and the piece of data in a play operation to play the data body on the distributing recording medium.