Copyright protection system, recording device, and reproduction device

A recording device for recording encrypted content on a recording medium, the recording medium having an unrewritable area in which a media number unique to the recording medium is recorded, comprising:

• a generating unit operable to acquire the media number from the recording medium, and generate license information by performing a specific operation using the media number and decryption information so that the license information reflects both the media number and the decryption information, the decryption information being necessary to decrypt the encrypted content;
• and
• a recording unit operable to record the license information, the decryption information, and the encrypted content on the recording medium.

A decryption device for decrypting encrypted content recorded on a recording medium, wherein the encrypted content, decryption information necessary to decrypt the encrypted content, and license information used for judging whether the encrypted content is permitted to be decrypted are recorded on the recording medium, and the recording medium has an unrewritable area in which a media number unique to the recording medium is recorded, comprising:

• a judging unit operable to read the media number, the decryption information, and the license information from the recording medium, and judge whether the read license information can be obtained if a specific operation is performed using the read media number and the read decryption information;
• and
• a decrypting unit operable to read the encrypted content from the recording medium and decrypt the encrypted content using the decryption information, only if the judgement by the judging unit is in the affirmative.

A recording method for recording encrypted content on a recording medium, the recording medium having an unrewritable area in which a media number unique to the recording medium is recorded, comprising:

• a generating step of acquiring the media number from the recording medium, and generating license information by performing a specific operation using the media number and decryption information so that the license information reflects both the media number and the decryption information, the decryption information being necessary to decrypt the encrypted content;
• and
• a recording step of recording the license information, the decryption information, and the encrypted content on the recording medium.

A decryption method for decrypting encrypted content recorded on a recording medium, wherein the encrypted content, decryption information necessary to decrypt the encrypted content, and license information used for judging whether the encrypted content is permitted to be decrypted are recorded on the recording medium, and the recording medium has an unrewritable area in which a media number unique to the recording medium is recorded, comprising:

• a judging step of reading the media number, the decryption information, and the license information from the recording medium, and judging whether the read license information can be obtained if a specific operation is performed using the read media number and the read decryption information;
• and
• a decrypting step of reading the encrypted content from the recording medium and decrypting the encrypted content using the decryption information, only if the judgement in the judging step is in the affirmative.

A recording program for use in a recording device for recording encrypted content on a recording medium, the recording medium having an unrewritable area in which a media number unique to the recording medium is recorded, the recording program having the recording device execute:

• a generating step of acquiring the media number from the recording medium, and generating license information by performing a specific operation using the media number and decryption information so that the license information reflects both the media number and the decryption information, the decryption information being necessary to decrypt the encrypted content;
• and
• a recording step of recording the license information, the decryption information, and the encrypted content on the recording medium.

A decryption program for use in a decryption device for decrypting encrypted content recorded on a recording medium, wherein the encrypted content, decryption information necessary to decrypt the encrypted content, and license information used for judging whether the encrypted content is permitted to be decrypted are recorded on the recording medium, and the recording medium has an unrewritable area in which a media number unique to the recording medium is recorded, the decryption program having the decryption device execute:

• a judging step of reading the media number, the decryption information, and the license information from the recording medium, and judging whether the read license information can be obtained if a specific operation is performed using the read media number and the read decryption information;
• and
• a decrypting step of reading the encrypted content from the recording medium and decrypting the encrypted content using the decryption information, only if the judgement in the judging step is in the affirmative.

A computer-readable storage medium storing a recording program for use in a recording device for recording encrypted content on a recording medium, the recording medium having an unrewritable area in which a media number unique to the recording medium is recorded, the recording program having the recording device execute:

• a generating step of acquiring the media number from the recording medium, and generating license information by performing a specific operation using the media number and decryption information so that the license information reflects both the media number and the decryption information, the decryption information being necessary to decrypt the encrypted content;
• and
• a recording step of recording the license information, the decryption information, and the encrypted content on the recording medium.

A computer-readable storage medium storing a decryption program for use in a decryption device for decrypting encrypted content recorded on a recording medium, wherein the encrypted content, decryption information necessary to decrypt the encrypted content, and license information used for judging whether the encrypted content is permitted to be decrypted are recorded on the recording medium, and the recording medium has an unrewritable area in which a media number unique to the recording medium is recorded, the decryption program having the decryption device execute:

• a judging step of reading the media number, the decryption information, and the license information from the recording medium, and judging whether the read license information can be obtained if a specific operation is performed using the read media number and the read decryption information;
• and
• a decrypting step of reading the encrypted content from the recording medium and decrypting the encrypted content using the decryption information, only if the judgement in the judging step is in the affirmative.

A recording medium comprising:

• an unrewritable area in which a media number unique to the recording medium is recorded;
• and
• a rewritable area in which (a) encrypted content, (b) decryption information necessary to decrypt the encrypted content, and (c) license information that is obtained by a specific operation using the media number and the decryption information and that reflects both the media number and the decryption information are recorded.