protected EllipticCurve(MyBigInteger a, MyBigInteger b, MyBigInteger p,
Func <MyBigInteger, MyBigInteger, MyBigInteger> equation)
{
this.a = a;
this.b = b;
this.p = p;
this.Zero = new EllipticCurvePoint(a.Zero(), b.Zero());
this.equation = equation;
}
public EllipticCurvePoint Add(EllipticCurvePoint first, EllipticCurvePoint second)
{
if (first is InfinityPoint)
{
return(second);
}
if (second is InfinityPoint)
{
return(first);
}
if (AreOpposite(first, second))
{
return(new InfinityPoint());
}
return(AreDifferent(first, second) ? AddDifferent(first, second) : DoublePoint(first));
}
public EllipticCurvePoint Add(EllipticCurvePoint first, EllipticCurvePoint second)
{
if (Zero.Equals(first))
{
return(second);
}
if (Zero.Equals(second))
{
return(first);
}
if (AreOpposite(first, second))
{
return(Zero);
}
return(AreDifferent(first, second) ? AddDifferent(first, second) : DoublePoint(first));
}
public bool Contains(EllipticCurvePoint point)
{
var res = equation(point.X, point.Y) % p;
return(res == point.X.Zero());
}
protected abstract EllipticCurvePoint AddDifferent(EllipticCurvePoint first, EllipticCurvePoint second);
protected abstract EllipticCurvePoint DoublePoint(EllipticCurvePoint point);
protected abstract bool AreDifferent(EllipticCurvePoint first, EllipticCurvePoint second);
protected abstract bool AreOpposite(EllipticCurvePoint first, EllipticCurvePoint second);
