Ejemplo n.º 1
0
Integer DL_GroupParameters_EC<EC>::GetCofactor() const
{
	if (!m_k)
	{
		Integer q = GetCurve().FieldSize();
		Integer qSqrt = q.SquareRoot();
		m_k = (q+2*qSqrt+1)/m_n;
	}

	return m_k;
}
Ejemplo n.º 2
0
bool DL_GroupParameters_EC<EC>::ValidateGroup(RandomNumberGenerator &rng, unsigned int level) const
{
	bool pass = GetCurve().ValidateParameters(rng, level);

	Integer q = GetCurve().FieldSize();
	pass = pass && m_n!=q;

	if (level >= 2)
	{
		Integer qSqrt = q.SquareRoot();
		pass = pass && m_n>4*qSqrt;
		pass = pass && VerifyPrime(rng, m_n, level-2);
		pass = pass && (m_k.IsZero() || m_k == (q+2*qSqrt+1)/m_n);
		pass = pass && CheckMOVCondition(q, m_n);
	}

	return pass;
}