Abstract: Various embodiments relate to a data processing system comprising instructions embodied in a non-transitory computer readable medium, the instructions for a cryptographic operation using masked compressing of coefficients of a polynomial having ns arithmetic shares for lattice-based cryptography in a processor, the instructions, including: shifting a first arithmetic share of the ns arithmetic shares by an input mask ?1; scaling the shifted first arithmetic share by a value based on a first compression factor ? and a masking scaling factor ?1; shifting the scaled first arithmetic share by a value based on the masking scaling factor ?1; scaling a second to ns shares of the ns arithmetic shares by a value based on the first compression factor ? and the masking scaling factor ?1; converting the ns scaled arithmetic shares to ns Boolean shares; right shifting the ns Boolean shares based upon the masking scaling factor ?1 and a second compression factor ?2; XORing an output mask ?2 with the shifted first Boolean s

Abstract: Various embodiments relate to a data processing system comprising instructions embodied in a non-transitory computer readable medium, the instructions for masked sampling of polynomials for lattice-based cryptography in a processor, the instructions, including: determining a number m of random bits to be sampled based upon a sample bound parameter ?; producing a plurality of Boolean masked shares of a polynomial coefficient each having the determined number m of random bits using a uniform random function; determining that the polynomial coefficient is within a range of values based upon the sample bound parameter ?; converting the plurality of Boolean masked shares of the polynomial coefficient to a plurality of arithmetic masked shares of the polynomial coefficient; and shifting the plurality of arithmetic masked shares based upon the sample bound parameter ?.

Abstract: Various implementations relate to a data processing system comprising instructions embodied in a non-transitory computer readable medium, the instructions for a cryptographic operation including a masked decomposition of a polynomial a having ns arithmetic shares into a high part a1 and a low part a0 for lattice-based cryptography in a processor, the instructions, including: performing a rounded Euclidian division of the polynomial a by a base ? to compute t(?)A; extracting Boolean shares a1(?)B from n low bits of t by performing an arithmetic share to Boolean share (A2B) conversion on t(?)A and performing an AND with ??1, where ?=???1 is a power of 2; unmasking a1 by combining Boolean shares of a1(?)B; calculating arithmetic shares a0(?)A of the low part a0; and performing a cryptographic function using a1 and a0(?)A.

Abstract: Various embodiments relate to a data processing system comprising instructions embodied in a non-transitory computer readable medium, the instructions for masked sampling of polynomials for lattice-based cryptography in a processor, the instructions, including: determining a number m of random bits to be sampled based upon a sample bound parameter ?; producing a plurality of Boolean masked shares of a polynomial coefficient each having the determined number m of random bits using a uniform random function; determining that the polynomial coefficient is within a range of values based upon the sample bound parameter ?; converting the plurality of Boolean masked shares of the polynomial coefficient to a plurality of arithmetic masked shares of the polynomial coefficient; and shifting the plurality of arithmetic masked shares based upon the sample bound parameter ?.