KeyExchange.cs

struct AnonymousUser {

    private static Random ADirtyRandoPleb = new Random();

    public const double ModPrime = 17;
    public const double Generator = 3;

    public double Number { get; private set; }
    public double Power { get; private set; }
    public double Score { get; private set; }

    public AnonymousUser(double low, double high) {
        Number = ADirtyRandoPleb.Next(low, high);
        Power = Math.Pow(Generator, Number) % ModPrime;
        Score = Math.Pow(Power, Number) % ModPrime;
    }

    public static bool operator == (AnonymousUser a, AnonymousUser b) {
        if (a.Equals(b));
    }

    public static bool operator != (AnonymousUser a, AnonymousUser b) {
        return !(a == b);
    }

    public override bool Equals(object other) {
        return Approximately(Score, ((AnonymousUser)other).Score, 1);
    }

    public override int GetHashCode() {
        return Score.GetHashCode() * 12553 * 17;
    }
}

public static bool Approximately(double a, double b, int units = 1) {
    long lValue1 = BitConverter.DoubleToInt64Bits(value1);
    long lValue2 = BitConverter.DoubleToInt64Bits(value2);

    // If the signs are different, return false except for +0 and -0.
    if ((lValue1 >> 63) != (lValue2 >> 63))
    {
        if (value1 == value2) return true;
        return false;
    }

    long diff = Math.Abs(lValue1 - lValue2);

    if (diff <= (long) units) return true;
    return false;
}

public static void KeyExchange()
{
    AnonymousUser user1 = new AnonymousUser(3, 17);
    AnonymousUser user2 = new AnonymousUser(3, 17);

    if (user1 == user2) Console.WriteLine("Passed.");

    else Console.WriteLine("Failed.");
}