php可以逆转的加密类
<? class encryptCalss { var $key=12; function encode($txt){ for($i=0;$i<strlen($txt);$i++){ $txt[$i]=chr(ord($txt[$i])+$this->key); } return $txt=urlencode(base64_encode(urlencode($txt))); } function decode($txt){ $txt=urldecode(base64_decode($txt)); for($i=0;$i<strlen($txt);$i++){ $txt[$i]=chr(ord($txt[$i])-$this->key); } return $txt; } } ?>