Schlumberger Systemes

Olivier Franchi

Eric Gerbault

Jean-Marc Gambin

A read system for reading at least one data item written in a memory ( ) of an electronic component ( ), the electronic component being suitable for communicating with a terminal and in particular for issuing an &ldquo;initialization response&rdquo; message (MRI) in response to an initialization signal (SI) issued by the terminal. The read system searches for the data item (DATA) in the memory ( ) and writes the data item in an initialization response message zone. A reader unit ( ) issues the initialization signal (SI) when the electronic component ( ) is connected to the unit ( ), and reads the data item (DATA) in the initialization response message zone. The reader unit also issues the initialization signal (SI) upon actuation of a forced initialization device ( ).

Data reading system in an electric component memory

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.

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Chaville, France

Olivier Franchi