Terminal device, server device, content recording control system, recording method, and recording permission control method

A terminal device outputting content recorded on a recording medium device, the terminal device comprising:

• a reading unit reading, from the recording medium device, content subject to output, signature data for the content, and a title key, the signature data including a hash value for each of a plurality of content pieces, a position of each of the content pieces, and a size of each of the content pieces;
• a determination unit calculating the hash value for each of the content pieces, determining whether calculated results match the hash value in the signature data for each of the content pieces, and preventing playback of the content when there is no match;
• a decrypting unit decrypting the content with use of the title key;
• and
• an output unit outputting decrypted content.

A control method used by a terminal device outputting content recorded on a recording medium device, comprising:

• reading, from the recording medium device, content subject to output, signature data for the content, and a title key, the signature data including a hash value for each of a plurality of content pieces, a position of each of the content pieces, and a size of each of the content pieces;
• calculating the hash value for each of the content pieces, determining whether calculated results match the hash value in the signature data for each of the content pieces, and preventing playback of the content when there is no match;
• decrypting the content with use of the title key;
• and
• outputting decrypted content.