| 摘要 |
A method for preventing the reproduction and illegal usage of a magnetic card and an apparatus thereof are provided to determine location for recording a noise pulse based on a location converting function for encryption and record the location of the noise pulse, thereby preventing the illegal usage of a card by reproduction. A noise pulse is written into a late synchronization code domain. When a magnetic card is read, the noise pulse is detected to determine whether the magnetic card is genuine. At the rising or falling edge location of a general data pulse signal or a pulse signal having 1/2 amplitude of the general data pulse signal, the noise pulse is written in the late synchronization code domain by performing OR computation between an original data pulse and the noise pulse having a range of amplitude of 5 to 30% of a general data pulse size. |
