double method

ProjectivAffinePoint double()

Doubles the ProjectivAffinePoint by performing point doubling operation.

Implementation

ProjectivAffinePoint double() {
  if (isZero()) {
    return ProjectivAffinePoint(curve, BigInt.zero, BigInt.zero);
  }

  final BigInt p = curve.p;
  final BigInt a = curve.a;

  final BigInt l =
      (BigInt.from(3) * x * x + a) *
      BigintUtils.inverseMod(BigInt.from(2) * y, p) %
      p;

  final BigInt x3 = (l * l - BigInt.from(2) * x) % p;
  final BigInt y3 = (l * (x - x3) - y) % p;

  return ProjectivAffinePoint(curve, x3, y3, order: null);
}