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US 9,313,027 B2Granted
Protection of a calculation performed by an integrated circuit
AssigneeProton World International N.V.
InventorsJean-Louis Modave, Thierry Huque
Life of this patent
Estimating the term…
Abstract
The calculation, by an electronic circuit, of a result of an integral number of applications of an internal composition law on elements of an abelian group, by successive iterations of different steps according to the even or odd character of a current coefficient of a polynomial representation of said integer, the degree of which determines the number of iterations, each iteration including whatever the even or odd character of the current coefficient, updating of at least one variable conditioning the final calculation result.
Claims16
A method, comprising:
- calculating, by an electronic circuit, a result of an integral number of applications of an internal composition law to elements of an abelian group and protecting the electronic circuit from attack during the calculating, by:
- performing iterations of the calculation with different operations based on an even or odd current coefficient of a polynomial representation of said integral number, the degree of which determines the number of iterations;
- for each iteration having an odd current coefficient, updating a first variable that contains, after all iterations, a final result of the calculation;
- and
- for each iteration having an even current coefficient, performing on a second variable an operation that does not modify the value of the second variable, to produce an intermediate result of the iteration, the intermediate result of the iteration being used in the final result of the calculation, wherein a fault injection attack causes the final result of the calculation to be modified independent of whether the current coefficient is even or odd.
2 more elements
An apparatus, comprising:
- one or more memories;
- and
- cryptographic circuitry coupled to the one or more memories, wherein the cryptographic circuitry, in operation,
- calculates a result of an integral number of applications of an internal composition law on elements of an abelian group, by successive iterations of different steps according to an even or odd character of a current coefficient of a polynomial representation of said integral number, the degree of which determines the number of iterations;
- and
- secures the calculating during execution of the iterations by,
- in case of an odd current coefficient in an iteration, updating a first variable that contains, after all iterations, a final result of the calculation;
- and
- in case of an even current coefficient in an iteration, performing on a second variable an operation that does not modify the value of the second variable, to produce an intermediate result of the iteration, the intermediate result of the iteration being used in the final result of the calculation, wherein a fault injection attack causes the final result of the calculation to be modified independent of whether the current coefficient is even or odd.
6 more elements
Dependencies are inferred from the claim text.