private BigInteger GenerateCoprimeNumber(BigInteger coprime)
{
BigInteger number = random.Next(2, (int)coprime - 1), nod = GCD.GetNOD(number, coprime);
while (nod != 1)
{
number = random.Next(2, (int)coprime - 1);
nod = GCD.GetNOD(number, coprime);
}
return(number);
}
public BigInteger[,] CreateDigitalSign(string text)
{
using (MD5 md5Hash = MD5.Create())
{
hash = MD5Hash.GetMd5Hash(md5Hash, text);
}
byte[] bytes = Encoding.ASCII.GetBytes(hash);
BigInteger[,] digitalSign = new BigInteger[bytes.Length, 2];
for (int i = 0; i < bytes.Length; i++)
{
do
{
BigInteger k = random.Next(2, (int)p - 2);
while (GCD.GetNOD(k, p - 1) != 1)
{
k = random.Next(2, (int)p - 2);
}
digitalSign[i, 0] = BigInteger.ModPow(g, k, p);
BigInteger temp = BigInteger.Multiply(BigInteger.Subtract(bytes[i], BigInteger.Multiply(x, digitalSign[i, 0])), GCD.ModInverse(k, p - 1));
digitalSign[i, 1] = temp < 0 ? (p - 1) - BigInteger.ModPow(BigInteger.Negate(temp), 1, p - 1) : BigInteger.ModPow(temp, 1, p - 1);
} while (digitalSign[i, 1] == 0);
}
return(digitalSign);
}
