| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optimum system configuration for preventing copying of a recording medium recorded with information necessary for copyright protection, or the like in a recording and reproducing drive device used in a computer environment and a PC system that is easy to edit information, or the like. <P>SOLUTION: An error correction code is generated from a main information signal (digital signal) and a specified information signal and added, and subsequently, a second modulator reproduces only the specified information signal and embeds the reproduced specified information signal in the same place. By doing that, in a reproduction processing, data demodulated by a first demodulator as they are in only the specified information signal become an error to be irreproducible, obtaining a security effect for the main information signal. In addition, the main information signal can be subjected to error correction processing by reproducing the specified information signal with a second demodulator and returning the result of reproduced specified information signal to a specified information arrangement place of the main information signal. A countermeasure against an increase in errors caused by embedding the specified information signal is made to improve a security capability for an encryption key, etc., used in copyright protection as well. <P>COPYRIGHT: (C)2004,JPO</p> |
