| 摘要 |
<p>PURPOSE:To prevent the generation of invalid writing or the alternation of contents by recording ciphered data in a magnetic card and recording a method for decoding the ciphered data. CONSTITUTION:When the magnetic card 10 is inserted, a card processor 1 reads out the ciphered data recorded in the card 10 and decoding data indicating the method for decoding the ciphered data and decodes the ciphered data by a decoding means 6. At the time of new updated data in the card 10, the card processor 1 encodes the updated data by an encoding means 5 based upon another ciphering sort and writes the encoded updated data and decoding data indicating the method for decoding the updated data in the card 1 by a writing means 3 to return both the data. Even if data recorded in the card 10 are inalidly read out, it is impossible for the contents to be read out until the specific card processor 1 is used.</p> |
