public string SN()
        {
            string Serial = RandomString(27, "23456789ABCDEFGHJKLMNPQRSTUVWXYZ");

            uint num = SerialBase.FromBase32(Serial.Substring(6, 2) + Serial.Substring(23, 2));

            Serial = Serial.Remove(14, 3);
            Serial = Serial.Insert(14, SerialBase.ToBase32(num, 3, 3));
            Serial = Serial.Remove(2, 2);
            Serial = Serial.Insert(2, SerialBase.ToBase32((uint)SerialBase.GetKeyValue(num, 27, 5, 190), 2, 2));
            Serial = Serial.Remove(12, 2);
            Serial = Serial.Insert(12, SerialBase.ToBase32((uint)SerialBase.GetKeyValue(num, 6, 114, 79), 2, 2));
            Serial = Serial.Remove(25, 2);
            Serial = Serial.Insert(25, SerialBase.ToBase32((uint)SerialBase.GetKeyValue(num, 39, 82, 86), 2, 2));
            Serial = Serial + SerialSystem.SerialBase.GetChecksum(Serial);
            return Serial;
        }


        private readonly Random _rng = new Random();

        private string RandomString(int size, string _chars)

        {

            int _charslen = _chars.Length;

            char[] buffer = new char[size];

            for (int i = 0; i < size; i++)

            {

                buffer[i] = _chars[_rng.Next(_charslen)];

            }

            return new string(buffer);

        }