PUBLIC KEY CRYPTOGRAPHIC METHOD OF PROTECTING ELECTRONIC CHIP AGAINST FRAUD IN TRANSACTIONS BETWEEN ELECTRONIC CHIP AND APPLICATION

摘要

PURPOSE: A public key cryptographic method of protecting an electronic chip against fraud in transactions between the electronic chip and an application is provided to protect the electronic chip by using an asymmetric encryption method. CONSTITUTION: An electronic chip generates a pseudo-random number r specific to the transaction by a serial pseudo-random generator included therein(1). The electronic chip transmits a parameter x to an application(2). The parameter x is calculated by the application prior to the transaction, is linked to the random number r by a mathematical relationship, and is stored in a data memory of the electronic chip. The electronic chip calculates a parameter y constituting an entire part or a part of an authentication value V by a serial function whose input parameters are at least the random number r specific to the transaction and a private key s belonging to an asymmetrical pair of keys(3). The electronic chip transmits the authentication value V to the application(4). The application verifies the authentication value V by a verification function whose input parameters consist exclusively of public parameters including at least the public key p(5).