public (CurvePoint, BigInteger) CreateKeys()
{
var closeKey = Algos.GenerateRandom(1, Curve.n - 1);
var openKey = Curve.G.MulOnScalar(closeKey);
return(openKey, closeKey);
}
public (ElGamalKey, ElGamalKey) GenerateKeys()
{
BigInteger prime, safePrime, generator;
while (true)
{
prime = Algos.GenetateRandomPrime(
BigInteger.Pow(2, dimension / 4),
BigInteger.Pow(2, dimension - 1),
Algos.MillerRabin
);
safePrime = 2 * prime + 1;
if (Algos.MillerRabin(safePrime))
{
break;
}
}
while (true)
{
generator = Algos.GenetateRandomPrime(3, safePrime - 2, Algos.MillerRabin);
if (BigInteger.ModPow(generator, 2, safePrime) != 1 && BigInteger.ModPow(generator, prime, safePrime) != 1)
{
break;
}
}
var closeKey = new ElGamalKey(Algos.GenerateRandom(2, safePrime - 2), generator, safePrime);
var openKey = new ElGamalKey(BigInteger.ModPow(generator, closeKey.Key, safePrime), generator, safePrime);
return(openKey, closeKey);
}
public Signature CreateSignature(BigInteger closeKey)
{
var z = GetHash();
while (true)
{
var k = Algos.GenerateRandom(1, Curve.n - 1);
var P = Curve.G.MulOnScalar(k);
var r = P.x % Curve.n;
if (r == 0)
{
continue;
}
var s = (Inverse(k, Curve.n) * (z + r * closeKey)) % Curve.n;
if (s == 0)
{
continue;
}
return(new Signature(r, s));
}
}