public static bool IsProbablyPrime(this long prime, int certainty, Ibasa.Numerics.Random.Generator random)
{
if (prime == 2 || prime == 3)
return true;
if (prime < 2 || prime % 2 == 0)
return false;
int s = 0;
var d = prime - 1;
while (d % 2 == 0)
{
d /= 2;
s += 1;
}
for (int i = 0; i < certainty; ++i)
{
long a = random.Next(2, prime - 2);
long x = Ibasa.Numerics.Functions.ModPow(a, d, prime);
if (x != 1 && x != prime - 1)
{
for (int r = 1; r < s; ++r)
{
x = Ibasa.Numerics.Functions.ModPow(x, 2, prime);
if (x == 1)
return false;
if (x == prime - 1)
break;
}
if (x != prime - 1)
return false;
}
}
return true;
}