Patent ID: 7840814

Claim:
A method of managing an original executable code forming a program to be downloaded into a reprogrammable on-board computer system in a microprocessor card, said code possessing a cryptographic signature and being executable by the microprocessor of the on-board system after verification by the latter of the validity of said signature, said method comprising the following steps: off card: identifying a modified executable code that is adapted to a predefined specific use, and corresponds to the original code, and calculating a software component according to the original intermediate code and the corresponding modified intermediate code identified for the predefined specific use, the software component, when applied to the original code, making it possible to produce the modified code; signing said software component; downloading the signed original code and the signed software component into the card; and on card: verifying the signatures respectively of the original code and of the software component, and applying the software component to the original code so as to produce the modified intermediate code for execution by the microprocessor.