我自己的加密～哈哈哈

#region enc
            string _userID = this.textBox1.Text;

            int keyword = 87;

            int leng = _userID.Length;

            Random rad = new Random();
            int radp = rad.Next(0, leng);

            string perid = "l" + _userID.Substring(0, radp) + "t" + _userID.Substring(radp) + (radp + keyword).ToString();


            this.textBox2.Text = perid;
            #endregion


            #region enp

            string bstring = this.textBox2.Text;

            int pword = Convert.ToInt32(bstring.Substring(bstring.Length - 2))-keyword;

            string p = bstring.Substring(1, pword) + bstring.Substring(pword + 2, bstring.Length - 2 - (pword + 2));

            this.textBox3.Text = p;


            #endregion