PHP加密解密的类

<p>class SysCrypt{</p>	private $crypt_key='http://www.scutephp.com';//密钥<br />	public function __construct($crypt_key){<br />		$this->crypt_key=$crypt_key;<br />	}<br />	public function encrypt($txt){<br />		srand((double)microtime()*1000000);<br />		$encrypt_key=md5(rand(0,32000));<br />		$ctr=0;<br />		$tmp='';<br />		for($i=0;$i<strlen($txt);$i++){<br />			$ctr=$ctr==strlen($encrypt_key)?0:$ctr;<br />			$tmp.=$encrypt_key[$ctr].($txt[$i]^$encrypt_key[$ctr++]);<br />		}<br />		return base64_encode(self::__key($tmp,$this->crypt_key));<br />	}<br />	public function decrypt($txt){<br />		$txt=self::__key(base64_decode($txt),$this->crypt_key);<br />		$tmp='';<br />		for($i=0;$i<strlen($txt);$i++){<br />			$md5=$txt[$i];<br />			$tmp.=$txt[++$i]^$md5;<br />		}<br />		return $tmp;<br />	}<br />	private function __key($txt,$encrypt_key){<br />		$encrypt_key=md5($encrypt_key);<br />		$ctr=0;<br />		$tmp='';<br />		for($i=0;$i<strlen($txt);$i++){<br />			$ctr=$ctr==strlen($encrypt_key)?0:$ctr;<br />			$tmp.=$txt[$i]^$encrypt_key[$ctr++];<br />		}<br />		return $tmp;<br />	}<br />	public function __destruct(){<br />		$this->crypt_key=NULL;<br />	}<br /><p>}</p>

<p>$sc=new SysCrypt('http://www.scutephp.com');</p>$text='yhm.1234@163.com';<br />$test1=$sc->encrypt($text);<br />echo '原文：',$text;<br />echo '<br />';<br />echo '密文：',$test1;<br />echo "<br/>";<br /><p>echo '解密：',</p><p>$sc->decrypt($test1);</p>