| 摘要 |
<p>The invention constitutes an improvement of access control security to data processing means, such as a smart card (MNV, MA), by simulating a comparison (E7) block by block (Si, Pi) of part of a secret code (S) with part of the presented code (P) through a block-by-block comparison (Pi, Aj) of part of the presented code and part of a number (A) when the presented code is found to be erroneous. Each time the card is used, a constant number of operations are applied to the presented code (P) and at least for part of the secret code (S) and at most for a complementary part relative to the number of operations, to the number (A), thus avoiding different signatures of power consumption for different presented codes.</p> |
