| 摘要 |
PROBLEM TO BE SOLVED: To detect the circulation of a very elaborate imitation at an early stage. SOLUTION: One of a plurality of predetermined first information for truth-or-falsehood judging is selectively embedded and recorded in main information, and one of a plurality of predetermined second information for truth-or-falsehood determination is recorded selectively on an authentic disk 1. When combination between the first and the second information coincides, a truth-or-falsehood determination circuit 6 decides the truth or falsehood of the recording medium by carrying out statistical processing of the combinations. Thus, it is detectable at an early stage that the very elaborate imitation is circulated. COPYRIGHT: (C)2007,JPO&INPIT |
