/// <summary>
/// Generates a new encryption key pair
/// </summary>
///
/// <param name="RngF">The random number generator to use for generating the secret polynomial f</param>
/// <param name="RngG">The random number generator to use for generating the secret polynomial g</param>
///
/// <returns>A key pair</returns>
private IAsymmetricKeyPair GenerateKeyPair(IRandom RngF, IRandom RngG)
{
int N = _encParams.N;
int q = _encParams.Q;
bool fastFp = _encParams.FastFp;
bool sparse = _encParams.Sparse;
TernaryPolynomialType polyType = _encParams.PolyType;
IPolynomial t = null;
IntegerPolynomial fq = null;
IntegerPolynomial fp = null;
IntegerPolynomial g = null;
if (ParallelUtils.IsParallel && _isParallel)
{
Action[] gA = new Action[] {
new Action(() => g = GenerateG(RngG)),
new Action(() => GenerateFQ(RngF, out t, out fq, out fp))
};
Parallel.Invoke(gA);
}
else
{
// Choose a random g that is invertible mod q.
g = GenerateG(RngG);
// choose a random f that is invertible mod 3 and q
GenerateFQ(RngF, out t, out fq, out fp);
}
// if fastFp=true, fp=1
if (fastFp)
{
fp = new IntegerPolynomial(N);
fp.Coeffs[0] = 1;
}
IntegerPolynomial h = g.Multiply(fq, q);
h.Mult3(q);
h.EnsurePositive(q);
NTRUPrivateKey priv = new NTRUPrivateKey(t, fp, N, q, sparse, fastFp, polyType);
NTRUPublicKey pub = new NTRUPublicKey(h, N, q);
return(new NTRUKeyPair(pub, priv));
}
