public override ECFieldElement Divide(ECFieldElement b)
{
//return Multiply(b.Invert());
uint[] z = Nat256.Create();
Mod.Invert(SecP256K1Field.P, ((SecP256K1FieldElement)b).x, z);
SecP256K1Field.Multiply(z, x, z);
return new SecP256K1FieldElement(z);
}