Patent ID: 6763461
Filing Date: 2004-07-13
Classification: G06K,G06Q,H04M

Abstract:
A method of detecting fraud involving use of an asynchronous circuit in the place of a card having an electronic circuit that is a synchronous circuit, the asynchronous circuit having a power-up time that is longer than a power-up time of the synchronous circuit, the method comprising the steps of:initiating power-up of the electronic circuit on the card, applying a given excitation signal to the electronic circuit of the card after the power-up time of the synchronous circuit has elapsed, recording a response pattern generated by the electronic circuit before the power-up time of the asynchronous circuit has elapsed, comparing said response pattern with a reference pattern corresponding to the response expected from the electronic circuit to said excitation signal if such electronic circuit is a synchronous circuit, and identifying a fraudulent use by means of an asynchronous circuit when the comparison is negative.