public void Sign(string message)
{
BigInteger[] s = RabinSystem.Signature(message, this.pqb);
this.signedmessage = message;
this.Signature = s[0];
this.n = s[1];
}
public static void Attack()
{
Console.Write("n = ");
BigInteger n = BigInteger.Parse("0" + Program.ReadLine(), NumberStyles.HexNumber);
int number_of_tries = 0;
while (true)
{
number_of_tries++;
BigInteger t = RabinSystem.RandomBigInteger(n);
BigInteger y = BigInteger.ModPow(t, 2, n);
Console.WriteLine("\ny = " + y.ToString("X"));
Console.Write("\nz = ");
BigInteger z = BigInteger.Parse("0" + Program.ReadLine(), NumberStyles.HexNumber);
if ((t == z) || (t == (n - z)))
{
Console.WriteLine("\nDidn't work! I'm trying again...");
continue;
}
else
{
BigInteger p = RabinSystem.egcd(t + z, n)[0];
BigInteger q = n / p;
if (p * q == n)
{
Console.WriteLine("\nVictory!\n\np = {0}\nq = {1}\n\nNumber of tries: {2}", p.ToString("X"), q.ToString("X"), number_of_tries);
Console.ReadLine();
return;
}
else
{
Console.WriteLine("Something went wrong!");
continue;
}
}
}
}
public void Interact()
{
Console.WriteLine("Hi! I'm Alice.");
while (true)
{
Console.WriteLine("\nWhat do you want me to do?\n");
Console.WriteLine("1. Generate private key and publish public key, then decipher a message.");
Console.WriteLine("2. Get public key and encrypt a message.");
Console.WriteLine("3. Generate private key and publish public key, then sign a message.");
Console.WriteLine("4. Get message and public key, then verify the signature.");
Console.WriteLine("0. Exit.\n");
Console.Write("Your choice is: ");
string choice = Console.ReadLine();
while (choice.Length != 1)
{
Console.WriteLine("Wrong choice! Try again:");
choice = Console.ReadLine();
}
switch (choice)
{
case "1":
this.GenKeys();
Console.WriteLine("\n\n p = " + this.pqb[0].ToString("X") + "\n\n q = " + this.pqb[1].ToString("X"));
Console.WriteLine("n = {0}", this.n.ToString("X"));
Console.WriteLine("b = {0}", this.pqb[2].ToString("X"));
Console.WriteLine();
this.CT = new BigInteger[3];
Console.WriteLine("Ciphertext: ");
this.CT[0] = BigInteger.Parse("0" + Program.ReadLine(), NumberStyles.HexNumber);
Console.WriteLine("Parity: ");
this.CT[1] = BigInteger.Parse(Console.ReadLine());
Console.WriteLine("Jacobi Symbol: ");
this.CT[2] = BigInteger.Parse(Console.ReadLine());
this.message = RabinSystem.Decrypt(this.CT, this.pqb);
Console.WriteLine("\nMessage is: {0}", this.message);
break;
case "2":
Console.WriteLine("n = ");
this.n = BigInteger.Parse("0" + Program.ReadLine(), NumberStyles.HexNumber);
Console.WriteLine("b = ");
this.b = BigInteger.Parse("0" + Program.ReadLine(), NumberStyles.HexNumber);
this.CT = RabinSystem.Encrypt("Yare, yare daze", this.n, this.b);
Console.WriteLine("Encrypted message is: {0}\nRarity is: {1}\nJacobi Symbol is:{2}", this.CT[0].ToString("X"), this.CT[1], this.CT[2]);
break;
case "3":
this.GenKeys();
Console.Write("\nSigned message is: ");
string message = Console.ReadLine();
BigInteger[] sign = RabinSystem.Signature(message, this.pqb);
Console.WriteLine("\nSign is: {0}\n\nModulo is: {1}", sign[0].ToString("X"), sign[1].ToString("X"));
break;
case "4":
Console.Write("\nMessage to verify is: ");
string signedmessage = Console.ReadLine();
Console.Write("\nIts signarute: ");
string signarute = Program.ReadLine();
Console.Write("\nIts modulo: ");
string n = Program.ReadLine();
Console.WriteLine("\nSignature is: " + RabinSystem.Verify(signedmessage, signarute, n));
break;
case "0":
return;
}
}
}
public void ReadMessage()
{
this.message = RabinSystem.Decrypt(this.CT, this.pqb);
}
public void SendMessageTo(Users user, string message)
{
user.SendPublicKeyTo(this);
user.CT = RabinSystem.Encrypt(message, this.n, this.b);
}
public void GenKeys()
{
this.pqb = RabinSystem.PrimeIntegrsGenerator();
this.n = pqb[0] * pqb[1];
}