Fault detection in post-quantum cyptography

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 including matrix multiplication for lattice-based cryptography in a processor, the instructions, including: applying a first function to the rows of a matrix of polynomials to generate first outputs, wherein the first function excludes the identity function; adding an additional row to the matrix of polynomials to produce a modified matrix, wherein each element in the additional row is generated by a second function applied to a column of outputs associated with each element in the additional row; multiplying the modified matrix with a vector of polynomials to produce an output vector of polynomials; applying a verification function to the output vector that produces an indication of whether a fault occurred in the multiplication of the modified matrix with the vector of polynomials; and carrying out a cryptographic operation using output vector when the verification function indicates that no fault occurred in the multiplication of the modified matrix with the vector of polynomials.