METHOD FOR SECURELY UPDATING A PROGRAM BLOCK LOADED IN A SECURITY MODULE

摘要

The aim of this invention is to propose a transmission method of a messagecontaining a program block that allows to avoid the consequences of apossible malicious decryption of this message.This aim is achieved through a secure method to update software embeddedin a security module, this method comprising the following steps:- formation of a first updating program block (PBI),- determination of a target memory zone of said security module,- determination through said security module, of a pre-registered content(MM_Ref) in said target memory zone ,- formation of a second program block (SBI) obtained by the mixing of allora part of the pre-registered content with the first program block (PBI),- transmission of the second program block (SBI) to the security module,- reception of the second block by the security module,- reading of the target memory zone (MEM),- obtaining and writing in the target memory zone of the first block by theinverse mixing of all or part of the second block and of the target memoryzone content.