class ption  {              private static $original = array('=', '+', '/');      private static $later = array('O0O0O', 'o0O0o', 'oo00o');          function __construct()      {                  }              private static function md5($skey = '')      {          $skey = $skey ? $skey : 'ui' ; //uicms::_config('security/authkey');                  return md5(substr($skey, 0, 16));      }              /**      * @use ption::en($string, $key);      * @param String $string 需要加密的字串      * @param String $skey 密钥      * @param int $expiry 密文有效期, 加密时候有效， 单位 秒，0 为永久有效      * @return String      */      static public function en($string = '', $skey = '', $expiry=0)      {                 if( is_array( $string ) )          {              $string = json_encode($string); // uicms::json($string, true, 'en');          }                         $string = str_pad($expiry ? $expiry + TIME : 0, 10, 0).$string;               $strArr = str_split(base64_encode($string));          $strCount = count($strArr);               $skey = static::md5($skey);               foreach (str_split($skey) as $key => $value)          {              $key < $strCount && $strArr[$key].=$value;          }          return str_replace(self::$original, self::$later, join('', $strArr));      }              /**      * @use ption::de($string, $key);      * @param String $string 需要解密的字串      * @param String $skey 密钥      * @return String      */      static public function de($string = '', $skey = '')      {                 $strArr = str_split(str_replace(self::$later, self::$original, $string), 2);          $strCount = count($strArr);          $skey = static::md5($skey);          foreach (str_split($skey) as $key => $value)          {              $key <= $strCount && $strArr[$key][1] === $value && $strArr[$key] = $strArr[$key][0];          }                 $result = base64_decode(join('', $strArr));                   if(substr($result, 0, 10) == 0 || substr($result, 0, 10) - TIME > 0)          {              return substr($result, 10);          }          else          {              return false;          }             }     }