zip_protect.php

<?php
class zip_protect{
  private $pass,$out,$input;
  function __construct($p,$i,$o){
    $this->pass = hash('sha512',$p);
    $this->out = $o;
    $this->input = $i;

    header("Content-type: application/octet-stream");
    header("Content-disposition: attachment; filename=$this->out");

    @system("zip -P $this->pass $this->out $this->input");
    readfile($this->out);
    @unlink($this->out);
  }
}
?>