Gemalto Sa

Alexandre Benoit

Ludovic Rousseau

Laurent Gauteron

Stéphane Socie

Michel Lombard

The invention relates to a verification of applications in interpreted language of the byte-code type (pseudo-code) loaded on portable electronic devices, in particular a chipcard and a method for verification of an application () interpreted by a virtual machine (), said application being loaded on a portable electronic device (), comprising at least one processor () and one RAM (). The method comprises carrying out the following after loading said application in the device and before validation thereof, checks in the code of said application by means of a process carried out by the processor (), characterized in comprising, on starting a sub-program, a step of backing up the actual verification context (to) in the RAM (), a step for creation and activation of a new verification context (to) for the sub-program and a step for restoration of the verification context (to) previously backed-up.

Method of verifying pseudo-code loaded in an embedded system, in particular a smart card

A method for managing an original executable code downloaded into a reprogrammable computer on-board system such as a microprocessor card. The code includes a cryptographic signature and is executable by the microprocessor once the validity of the signature has been checked. Off the card, a modified executable code corresponding to the original code and adapted to a pre-defined specific use is identified. A software component is calculated, which when applied to the original code, enables the modified code to be reconstructed. The software component is signed, and the signed original code and the signed software component are downloaded into the card. On the card, the signature of the original code and the software component are checked, and the software component is applied to the original code in order to reconstruct the modified code for the execution of the same by the microprocessor.

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Marseilles, France

Alexandre Benoit