| 摘要 |
PURPOSE:To easily execute the falsification check and justification check of data by recording data for falsification check, in which all the bits of recording data and storage data are inverted at the time of recording data. CONSTITUTION:Recording data 1 and check data in which all bits are inverted are recorded in an optical card at the time of recording data. The recording medium of the optical card is punched by a laser beam and the reading system is that recorded data is detected by the presence and absence of the hole by the strength of the reflection of the irradiation laser beam. Since the punched bit is unreproducible, data falsification is attained only in a punching direction. If data on the optical card is falsified by a third person, data and the bits concerned of check data come into punched state, and they are identified to be falsified. With only checking that all bits of recorded data 1 and those of check data are in an inverted relation, the falsification check of recorded data on the laser card can be executed. |
