scale method

ProjectiveECCPoint scale()

The coordinates are updated to the scaled values, and the scaled point is returned.

Implementation

ProjectiveECCPoint scale() {
  final currentZ = _coords[2];

  /// If the current z-coordinate is already one, no need to scale
  if (currentZ == BigInt.one) {
    return this;
  }
  final currentY = _coords[1];
  final currentX = _coords[0];

  /// Get the prime field value
  final primeField = curve.p;

  /// Calculate the modular inverse of z
  final zInverse = BigintUtils.inverseMod(currentZ, primeField);

  /// Calculate z-inverse squared
  final zInverseSquared = (zInverse * zInverse) % primeField;

  /// Scale the x and y coordinates
  final scaledX = (currentX * zInverseSquared) % primeField;
  final scaledY = (currentY * zInverseSquared * zInverse) % primeField;

  /// Update the coordinates to the scaled values
  _coords = [scaledX, scaledY, BigInt.one];

  return this;
}