return null;
if (isInfinity() || (x.toBigInteger().equals(BigInteger.ZERO))) {    return new ECPoint.F2m(curve); }  ECFieldElement.F2m lambda = (ECFieldElement.F2m)x.add(y.divide(x));  ECFieldElement.F2m x3 = (ECFieldElement.F2m)lambda.square().add(lambda). add(curve.getA());  ECFieldElement.F2m y3 = (ECFieldElement.F2m)x.square().add(lambda.multiply(x3)). add(x3);  return new ECPoint.F2m(curve, x3, y3);
        public ECPoint twice()        {            // TODO Auto-generated method stub            return null;        }