Patent ID: 6848619

Claim:
A portable object of smartcard type, comprises: a microcontroller comprising a part to carry out data processing, the data comprising confidential information; a contact stud to supply said microcontroller with a current; a data input and/or output contact stud; and an interface circuit through which the part to carry out data processing receives a supply voltage, said interface circuit being designed to vary the supply voltage of the part to carry out data processing by modulating the electrical couple between the contact stud and the part to carry out data processing in order to secure said confidential data against current attacks, wherein said interface circuit comprises: a switch between the contact stud and a supply terminal of the part to carry out data processing, a capacitor connected between said supply terminal of the part to carry out data processing of the microcontroller and another supply terminal of the part to carry out data processing, and a pulse generator to control the switch in a desynchronized manner with respect to said data processing.