| 摘要 |
PURPOSE:To avoid the easy reading of the secret code by giving some modification via the random signals or the like to the secret code which is recorded on the magnetic card used for the cash dispenser or the like. CONSTITUTION:Random pattern generators 12 and 13 generate the random data of 16 and 8 bits each via the clock signals sent from oscillators OSC10 and 11 featuring the unsteady oscillation frequency each. These random data are artificial featuring the cyclic properties. The secret code is supplied to circuit 18 and then written into data buffer 20 after undergoing the operation with the random data. After this, receiving the operation with the other random data at circuit 17, the secret code is supplied to card data buffer 21. The head data of each random data is also supplied to buffer 21 via register 16, and the contents of buffer 21 is recorded on the card via the card writing circuit. The device which reads the information recorded on the card is also shown. |
