Charge pump based subsystem for secure smart-card design
OwnerPasquale Corsonello, Martin Margala +1inventors
InventorsPasquale Corsonello, Martin Margala, Stefania Perri
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Abstract
A smart card includes a power source, a processing chip, and a charge-pump subsystem for powering the processing chip. The charge-pump subsystem includes a capacitor which is connected cyclically to the power source to charge the capacitor, to the processing chip to power the processing chip, and to ground to discharge the capacitor. The charge-pump subsystem can include three such capacitors so that while one of them is charging, another is powering the processing chip, and a third is discharging. The charge-pump subsystem blocks attempts to discover a secret key in the processing chip by decorrelating power consumption from the internal operations of the processing device.
Claims24
A charge-pump subsystem for powering a processing device from a power source, the charge-pump subsystem comprising:
- a charge pump capacitor for being charged by the power source and pumping charge into the processing device;
- and
- a switch for connecting the charge pump capacitor in a first phase to the power source to charge the capacitor, in a second phase to the processing device to power the processing device, and in a third phase to ground to discharge the charge pump capacitor, such that no two of the first, second and third phases overlap in time;
- wherein a switching rate of the switch is higher than a clock speed of the processing device.
A method for powering a processing device from a power source by using a charge pump subsystem which comprises a charge pump capacitor, the method comprising:
- (a) connecting the power source to the charge pump capacitor to charge the capacitor;
- (b) connecting the charge pump capacitor to the processing device to power the processing device;
- and
- (c) connecting the charge pump capacitor to ground to discharge the capacitor;
- wherein no two of steps (a), (b) and (c) overlap in time, and wherein steps (a), (b) and (c) are performed within a single clock cycle of the processing device.
A processing system comprising:
- a power source;
- a processing device;
- and
- a charge-pump subsystem for powering the processing device from the power source, the charge-pump subsystem comprising:
- a charge pump capacitor;
- and
- a switch for connecting the charge pump capacitor in a first phase to the power source to charge the charge pump capacitor, in a second phase to the processing device to power the processing device, and in a third phase to ground to discharge the charge pump capacitor, such that no two of the first, second and third phases overlap in time, wherein a switching rate of the switch is higher than a clock speed of the processing device.
A smart card comprising:
- a power source
- a processing device;
- and
- a charge pump subsystem for powering the processing device from the power source;
- wherein the power source, the processing device and the charge pump subsystem are integrated into the smart card, and wherein a switching rate of the charge pump subsystem is higher than a clock speed of the processing device.
Dependencies are inferred from the claim text.