Schlumberger Systemes

Eric Gerbault

Olivier Franchi

Jean-Marc Gambin

A method of managing integrity defects concerning data written in a rewritable memory of an electronic component, said electronic component being suitable for performing operations that are capable of modifying at least some of said data and of interchanging information relating to said operations either off-line, directly with a terminal, or else on-line, with an issuer via said terminal. According to the invention, said method consists in: defining firstly &ldquo;main&rdquo; data in which an integrity defect is representative of faulty operation of the rewritable memory, and secondly &ldquo;secondary&rdquo; data in which an integrity defect is representative either of faulty operation of the rewritable memory, or else of an interruption in the power supply to the electronic component; on each operation, checking the integrity of at least some data; if a check on the integrity of at least some of the main data reveals an integrity defect, preventing any further operation; and if an integrity check on secondary data reveals an integrity defect, allocating at least one default value to at least one item of secondary data, thereby requiring an interchange to be performed on-line during the following operation. The invention is applicable to making secure transactions performed by means of electronic memory cards.

Growing community of inventors

Le Kremlin Bicêtre, France

Eric Gerbault