System.Web.Security.FormsAuthentication.Encrypt C# (CSharp) Method

		public static string Encrypt (FormsAuthenticationTicket ticket)
		{
			if (ticket == null)
				throw new ArgumentNullException ("ticket");

			Initialize ();
			byte [] ticket_bytes = ticket.ToByteArray ();
			if (protection == FormsProtectionEnum.None)
				return Convert.ToBase64String (ticket_bytes);

			byte [] result = null;
			MachineKeySection config = (MachineKeySection) WebConfigurationManager.GetWebApplicationSection (machineKeyConfigPath);

			if (protection == FormsProtectionEnum.All) {
				result = MachineKeySectionUtils.EncryptSign (config, ticket_bytes);
			} else if (protection == FormsProtectionEnum.Encryption) {
				result = MachineKeySectionUtils.Encrypt (config, ticket_bytes);
			} else if (protection == FormsProtectionEnum.Validation) {
				result = MachineKeySectionUtils.Sign (config, ticket_bytes);
			}

			return Convert.ToBase64String (result);
		}

        protected void Button1_Click(object sender, EventArgs e)
        {
            if (txtusername.Text == "admin" && txtpwd.Text == "admin")
            {
                //会话性cookie保存于内存中。关闭浏览器则会话性cookie会过期消失；持久化cookie则不会，直至过期时间已到或确认注销。

                FA.SetAuthCookie(txtusername.Text, true);


                #region 票据验证

                string userData = "序列化对象";
                FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1,
                                                                                 txtusername.Text,
                                                                                 DateTime.Now,
                                                                                 DateTime.Now.AddMinutes(720),
                                                                                 true,
                                                                                 userData,
                                                                                 FA.FormsCookiePath);

                // 加密票证
                string encTicket = FA.Encrypt(ticket);

                // 创建cookie
                HttpCookie cookie = new HttpCookie(FA.FormsCookieName, encTicket);
                cookie.HttpOnly = true;
                cookie.Secure   = FA.RequireSSL;
                cookie.Domain   = FA.CookieDomain;
                cookie.Path     = FA.FormsCookiePath;
                if (ticket.IsPersistent)
                {
                    cookie.Expires = DateTime.Now.AddMinutes(720);
                }

                HttpContext.Current.Response.Cookies.Add(cookie);

                #endregion

                Response.Redirect("admin/index.aspx");
            }
            else
            {
                Response.Write("用户名或密码错误");
            }
        }