private BigInteger GeneratePrimeNumber()
{
BigInteger number;
do
{
number = random.Next(100, 500);
} while (!GCD.IsSimple(number));
return(number);
}
private BigInteger GeneratePrimeNumber()
{
BigInteger number = random.Next(4, 1000);
while (!GCD.IsSimple(number))
{
number = random.Next(4, 1000);
}
return(number);
}
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 RSA()
{
p = GeneratePrimeNumber();
q = GeneratePrimeNumber();
n = p * q;
fi = (p - 1) * (q - 1);
e = GenerateCoprimeNumber(fi);
d = GCD.ModInverse(e, fi);
Console.WriteLine(new string('-', 40) + "Digital sign via RSA" + new string('-', 40));
Console.WriteLine($"p = {p}, q = {q}, n = p * q = {p * q}, fi(n) = {fi}, e = {e}, d = {d}\n");
Console.WriteLine($"PUBLIC KEY: (e, n) = ({e}, {n})");
Console.WriteLine($"PRIVATE KEY: (d, n) = ({d}, {n})");
Console.WriteLine();
}
public Schnorr()
{
do
{
q = GeneratePrimeNumber();
} while ((p - 1) % q != 0);
do
{
g = random.Next(10000, 15000);
} while (g == 1 || BigInteger.ModPow(g, (int)q, p) != 1);
do
{
x = random.Next((int)q);
} while (x >= q);
y = GCD.ModInverse(BigInteger.ModPow(g, x, p), p);
Console.WriteLine(new string('-', 40) + "Digital sign via Snorr" + new string('-', 40));
Console.WriteLine($"p = {p}, q = {q}, g = {g}, x = {x}, y = {y}\n");
Console.WriteLine($"PUBLIC KEY: (p, q, g, y) = ({p}, {q}, {g}, {y})");
Console.WriteLine($"PRIVATE KEY: (x) = ({x})");
Console.WriteLine();
}
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);
}
