polysub function

Poly polysub(
  1. Poly a,
  2. Poly b
)

Component-wise subtraction of two polynomials.

Implementation

Poly polysub(Poly a, Poly b) {
  Poly r = Poly();
  for (int i = 0; i < KYBER_N; i++) {
    r.coeffs[i] = fqsub(a.coeffs[i], b.coeffs[i]);
  }
  return r;
}