| 摘要 |
<p>A personal identification card bearing machine-readable data is coded on at least two levels, preferably in spatially separate places, each card owner being assigned a secret number which is coded at the two levels, and on at least one of the levels secret information carried on the card is also used in this coding. The personal identification number (PIN) of the user may be processed to an intermediate value on the first coding level then processed on the second level to a code number (which is stored on the card) by using secret information read from the card. <IMAGE></p> |
