数据加密1(可逆)

/// <summary>
  /// 加密字符串
  /// </summary>
  /// <returns>string</returns>
using System.Web.Security;
  public static string Encrypt(string stringToEncrypt)
  {
   string str = "";
   FormsAuthenticationTicket ticket = new System.Web.Security.FormsAuthenticationTicket(stringToEncrypt,true,2);
   str = FormsAuthentication.Encrypt(ticket).ToString();
   return str;
  }

/// <summary>
  /// 解密字符串
  /// </summary>
  /// <param name="stringToDecrypt">加密过了的字符串</param>
  /// <returns></returns>
  public static string Decrypt(string stringToDecrypt)
  {
   string str = "";
   str = FormsAuthentication.Decrypt(stringToDecrypt).Name.ToString();
   return str;
  }