Countermeasure to power analysis attacks through time-varying impedance of power delivery networks
First Claim
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1. A method for a countermeasure to a power analysis attack, the method comprising:
- coupling a plurality of impedance elements to a pair of nodes of a power delivery network coupled between a power source and an integrated circuit, the power source providing power to a cryptographic device integrated within the integrated circuit, the cryptographic device causing a measurable power supply noise;
generating a timing sequence based on an activity of the cryptographic device; and
selectively decoupling one or more of the plurality of impedance elements from the pair of nodes of the power delivery network according to the timing sequence to cause the measurable power supply noise to vary according to the timing sequence when an operation of the cryptographic device is being performed, the measurable power supply noise varying based on a number of the one or more of the plurality of impedance elements that are selectively decoupled according to the timing sequence.
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Abstract
A method and system for a countermeasure to power analysis attacks, where an impedance element is coupled to a power source providing power to a cryptographic module causing a measurable power supply noise, a timing sequence is generated, and the impedance element is decoupled from the power source based on the timing sequence to cause the measurable power supply noise to vary according to the timing sequence.
37 Citations
20 Claims
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1. A method for a countermeasure to a power analysis attack, the method comprising:
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coupling a plurality of impedance elements to a pair of nodes of a power delivery network coupled between a power source and an integrated circuit, the power source providing power to a cryptographic device integrated within the integrated circuit, the cryptographic device causing a measurable power supply noise; generating a timing sequence based on an activity of the cryptographic device; and selectively decoupling one or more of the plurality of impedance elements from the pair of nodes of the power delivery network according to the timing sequence to cause the measurable power supply noise to vary according to the timing sequence when an operation of the cryptographic device is being performed, the measurable power supply noise varying based on a number of the one or more of the plurality of impedance elements that are selectively decoupled according to the timing sequence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for a countermeasure to a power analysis attack, the system comprising:
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an integrated circuit comprising cryptographic circuitry; a pair of power supply pads coupled to the integrated circuit and configured to supply power to the integrated circuit from a power source; a portion of a power delivery network disposed on the integrated circuit, the portion of the power delivery network is coupled to the pair of power supply pads, wherein the portion comprises components to provide or shunt power in response to changes in power demand of the integrated circuit, wherein the cryptographic circuitry causes a measurable power supply noise; a time-varying impedance subcircuit selectively coupled to and decoupled from the portion of the delivery network, the time-varying impedance subcircuit comprises; a plurality of impedance elements configured to be coupled to and decoupled from the pair of power supply pads when providing power to the cryptographic circuitry that causes the measurable power supply noise; a plurality of switching elements coupled to the plurality of impedance elements; and a timing sequence generator circuit coupled to the plurality of switching elements, the timing sequence generator circuit to generate a timing sequence based on an activity of the cryptographic circuitry, wherein one or more of the impedance elements are decoupled from the pair of power supply pads via one or more of the plurality of switching elements based on the timing sequence to cause the measurable power supply noise to vary according to the timing sequence when an operation of the cryptographic circuitry is being performed, the measurable power supply noise varying based on a number of the one or more of the plurality of impedance elements that are selectively decoupled via the one or more of the plurality of switching elements based on the timing sequence. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. An apparatus comprising:
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a portion of a power delivery network coupled to a power supply during operation; a cryptographic device comprising a cryptographic circuit to execute a cryptographic operation, wherein the cryptographic circuit is powered by power supplied to the cryptographic device via the portion of the power delivery network and the cryptographic circuit causes a measurable power supply noise during operation; a plurality of switching components controlled via a random timing sequence that is based on an activity of the cryptographic circuit; and a plurality of impedance elements, wherein one or more of the plurality of impedance elements are selectively coupled to the portion of the power delivery network using the plurality of switching components according to the random timing sequence to randomly vary impedance of the power delivery network to randomly vary the measurable power supply noise when the cryptographic operation of the cryptographic circuit is being performed, the measurable power supply noise varying based on a number of the one or more of the plurality of impedance elements that are selectively coupled to the portion of the power delivery network using the plurality of switching components according to the random timing sequence. - View Dependent Claims (20)
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Specification