/**
* {@inheritDoc}
* @see \Mdanter\Ecc\PointInterface::getDouble()
*/
public function getDouble()
{
if ($this->isInfinity()) {
return $this->curve->getInfinity();
}
$math = $this->adapter;
$modMath = $this->modAdapter;
$a = $this->curve->getA();
$threeX2 = $math->mul(3, $math->pow($this->x, 2));
$tangent = $modMath->div($math->add($threeX2, $a), $math->mul(2, $this->y));
$x3 = $modMath->sub($math->pow($tangent, 2), $math->mul(2, $this->x));
$y3 = $modMath->sub($math->mul($tangent, $math->sub($this->x, $x3)), $this->y);
return new self($this->adapter, $this->curve, $x3, $y3, $this->order);
}
/**
* {@inheritDoc}
* @see \Mdanter\Ecc\CurveFpInterface::cmp()
*/
public function cmp(CurveFpInterface $other)
{
$math = $this->adapter;
$equal = $math->cmp($this->a, $other->getA()) == 0;
$equal &= $math->cmp($this->b, $other->getB()) == 0;
$equal &= $math->cmp($this->prime, $other->getPrime()) == 0;
return $equal ? 0 : 1;
}
