Patent ID: 7971785

Claim:
A method for authenticating micro-processor cards to determine whether a card is a genuine card, supplied by an authorised distributor, or a fake card, known as a clone, supplied by an unauthorised third party, by a checking program of at least one card reader terminal, said program sending to each card commands belonging to a standard and public set of commands, wherein the method comprises: a preliminary step of modifying said checking program in said terminal or terminals, in such a way that said program additionally sends, to each card to be authenticated, at least one additional command, called a secret command, from a set of at least one additional command, pre-inserted into each genuine card, and different from said standard and public set of commands; a step of detecting the authenticity of said card, if said secret command is recognised and/or processed correctly, or the presence of a clone, if said secret command is not recognised and/or is processed wrongly.