System for processing the data from a microcircuit card, card and reader for this system and method of implementation

摘要

The card (10) comprises a memory (12) with at least: a non-modifiable area containing an identifying information item (13); a modifiable area containing the data to be processed (15); and a modifiable area containing a certificate (14) recalculated, during each transaction modifying the data, on the basis of at least one parameter internal to the card and at least one parameter outside the card. According to the invention, it moreover includes: read and/or write inhibitor means (17) operating selectively on the various areas of the memory so that the data area and the certificate area are modifiable only conditionally and so that the certificate area is unreadable from outside; and means (18) for comparing the certificate contained in the memory with a certificate calculated by a reader (20) cooperating with the card, in order to determine the conformity of the comparison made by the card and to authorise write access to the data area and to the certificate area only in the event of agreement. <IMAGE>