Multiplier protected against power analysis attacks
AssigneeNuvoton Technology Corporation
InventorMoshe Alon
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Abstract
A multi-word multiplier circuit includes an interface and circuitry. The interface is configured to receive a first parameter X including one or more first words, and a second parameter Y′ including multiple second words. The second parameter includes a blinded version of a non-blinded parameter Y that is blinded using a blinding parameter AY so that Y′=Y+AY. The circuitry is configured to calculate a product Z=X·Y by summing multiple sub-products, each of the sub-products is calculated by multiplying a first word of X by a second word of Y′, and subtracting from intermediate temporary sums of the sub-products respective third words of a partial product P=X·BY, BY is a blinding word included in AY.
Claims16
A multi-word multiplier circuit, comprising:
- an interface configured to receive:
- a first parameter X comprising one or more first words;
- and
- a second parameter Y′ comprising multiple second words, wherein the second parameter comprises a blinded version of a non-blinded parameter Y that is blinded using a blinding parameter AY so that Y′=Y+AY;
- and
- circuitry, configured to calculate a product Z=X·Y by summing multiple sub-products, wherein each of the sub-products is calculated by multiplying a first word of X by a second word of Y′, and subtracting from intermediate temporary sums of the sub-products respective third words of a partial product P=X·BY, wherein BY is a blinding word comprised in AY.
A method, comprising:
- in a multi-word multiplier circuit receiving a first parameter X comprising one or more first words, and a second parameter Y′ comprising multiple second words, wherein the second parameter comprises a blinded version of a non-blinded parameter Y that is blinded using a blinding parameter AY so that Y′=Y+AY;
- and
- calculating a product Z=X·Y by summing multiple sub-products, wherein each of the sub-products is calculated by multiplying a first word of X by a second word of Y′, and subtracting from intermediate temporary sums of the sub-products respective third words of a partial product P=X·BY, wherein BY is a blinding word comprised in AY.
Dependencies are inferred from the claim text.