lib/ed25519_keccak/ed25519base.rb
def point_mul(s, pa)
      pq = [0, 1, 1, 0]  # Neutral element
      while s > 0 do
        pq = point_add(pq, pa) unless (s & 1).equal? 0
        pa = point_add(pa, pa)
        s >>= 1
      end
      return pq
    end
def point_mul(s, pa)
      pq = [0, 1, 1, 0]  # Neutral element
      while s > 0 do
        pq = point_add(pq, pa) unless (s & 1).equal? 0
        pa = point_add(pa, pa)
        s >>= 1
      end
      return pq
    end
Computes pointQ = s * pointA