/// <summary>
/// Decrypts an integer polynomial
/// </summary>
///
/// <param name="E">Encrypted polynomial</param>
/// <param name="PrivT">A polynomial such that if <c>fastFp=true</c>, <c>f=1+3*priv_t</c>; otherwise, <c>f=priv_t</c></param>
/// <param name="PrivFp">Fp</param>
///
/// <returns>Derypted polynomial</returns>
private IntegerPolynomial Decrypt(IntegerPolynomial E, IPolynomial PrivT, IntegerPolynomial PrivFp)
{
int q = _encParams.Q;
IntegerPolynomial a;
if (_encParams.FastFp)
{
a = PrivT.Multiply(E, q);
a.Multiply(3);
a.Add(E);
}
else
{
a = PrivT.Multiply(E, q);
}
a.Center0(q);
a.Mod3();
IntegerPolynomial c = _encParams.FastFp ? a : new DenseTernaryPolynomial(a).Multiply(PrivFp, 3);
c.Center0(3);
return(c);
}
