public static Signature Sign(SecretKey secretKey, string message)
{
var numberK = Utils.GenerateNumber().Mod(Static.Q - 2) + 2; // Crete 1 < k < q
var matrixR =
secretKey.MatrixD.Pow(secretKey.NumberW).Inverse() *
secretKey.MatrixG.Pow(numberK) *
secretKey.MatrixU.Pow(secretKey.NumberT);
byte[] hash;
using (SHA512 shaM = new SHA512Managed())
{
var bytes = Utils.ConcatBytes(Encoding.Unicode.GetBytes(message), matrixR.ToBytes());
hash = shaM.ComputeHash(bytes);
}
var numberE = new BigInteger(hash);
var numberEModed = numberE.Mod();
Static.NumberE = numberEModed;
var numberS = (numberK + numberEModed * secretKey.NumberX).Mod(Static.Q);
return(new Signature {
NumberE = numberEModed, NumberS = numberS
});
}
public static bool Verify(PublicKey publicKey, Signature signature, string message)
{
var matrixR =
publicKey.MatrixY.Pow(
(publicKey.PrimeNumber
- signature.NumberE).Mod(Static.Q)) *
publicKey.MatrixL *
publicKey.MatrixZ.Pow(signature.NumberS);
var matrixRModed = new Matrix(matrixR[1].Mod(), matrixR[2].Mod(), matrixR[3].Mod(), matrixR[4].Mod());
byte[] hash;
using (SHA512 shaM = new SHA512Managed())
{
var bytes = Utils.ConcatBytes(Encoding.Unicode.GetBytes(message), matrixRModed.ToBytes());
hash = shaM.ComputeHash(bytes);
}
var numberE = new BigInteger(hash);
var numberEModed = numberE.Mod();
return(numberEModed.Equals(signature.NumberE));
}
