| 摘要 |
PROBLEM TO BE SOLVED: To provide a copy preventing method in a form using an ordinary CD-ROM drive. SOLUTION: Since a subdata area 2 where errors are to be generated at the time of reading is prepared at the arbitrary part in the area of the main data 1 of a CD-ROM and this media (a) can not be read out as it is in an ordinary CD-R or the like and the software in this CD-ROM is decided by whether it is an original or a copy based on an algorithm (b), this media (a) can not be used even when it is force-copied. |
