PHP加密解密的类

代码如下：

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

该类使用方法：

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

输出结果类似：

原文：yhm.1234@163.com