Jacques Peyriére

Fast tensor transforms and ring-valued orthogonal matrices: an application to cryptography

We present a generalization of the Fast Fourier and fast Walsh transform algorithms to tensor products of $n$ arbitrary $q\times q$ matrices over a commutative ring, reducing the cost of applying such a tensor product from $q^{2n}$ to $nq^{n}$ ring operations. We then give an explicit construction of square orthogonal...