| 摘要 |
PURPOSE:To prevent information recorded on a medium from illegally being used by recording ciphered information at a 1st information recording part by a writer, and decoding the recorded information by a reader/according to deciphering information recorded at a 2nd information recording part and outputting the result. CONSTITUTION:A flexible disk 1 is provided with a magnetic disk 3 as a 1st recording part and a case 4 provided with a 2nd recording part 5 which can be read by the optical read part of a reader writer. Magnetic data recorded on the magnetic disk 3 are ciphered by a reader/writer so that the data can be deciphered with the data recorded at the 2nd recording part 5. Therefore, the data on the magnetic disk 3 can not be utilized unless the data recorded at the 2nd recording part 5 are read. Namely, an expensive optical information recording system needs to be used to analyze or forge the complicated contents of the optical information recording part, and the information recording system need not be standardized and can be made complicate. |
