private void gen_key_Click(object sender, EventArgs e)
        {
            int keysize = Convert.ToInt32(key_size.SelectedItem.ToString());

            SK              = generator.Get_Key(keysize);
            p               = generator.P;
            PK              = generator.PUBLIC_KEY;
            G               = generator.G;
            p_value.Text    = p.ToString();
            secret_key.Text = SK.ToString();
            public_key.Text = PK.ToString();
            g_value.Text    = G.ToString();
            encryption      = new ElgamalCrypto(PK, p, G, SK, keysize);
        }
        private void key_file_Click(object sender, EventArgs e)
        {
            OpenFileDialog get_file  = new OpenFileDialog();
            string         file_name = "";

            if (get_file.ShowDialog() == DialogResult.OK)
            {
                file_name = get_file.FileName;
            }
            string[] keys = new string[4];
            try
            {
                using (StreamReader sr = new StreamReader(file_name))
                {
                    string line;
                    int    count = 0;
                    while ((line = sr.ReadLine()) != null)
                    {
                        keys[count++] = line;
                    }
                    if (keys[0].Length <= 320)
                    {
                        key_size.Text = 1024.ToString();
                        size          = 1024;
                    }
                    else
                    {
                        key_size.Text = 2048.ToString();
                        size          = 2048;
                    }
                    p  = BigInteger.Parse(keys[0]);
                    SK = BigInteger.Parse(keys[1]);
                    PK = BigInteger.Parse(keys[2]);
                    G  = BigInteger.Parse(keys[3]);
                }
                p_value.Text    = p.ToString();
                secret_key.Text = SK.ToString();
                public_key.Text = PK.ToString();
                g_value.Text    = G.ToString();
                encryption      = new ElgamalCrypto(PK, p, G, SK, size);
            }
            catch
            {
                return;
            }
        }