function encryptInit($id)
    {
        $tmp = $this->encryptionKey;
        $hex = dechex($id);
        if (mb_strlen($hex, '8bit') < 6) {
            $hex = substr('000000', 0, 6 - mb_strlen($hex, '8bit')) . $hex;
        }
        $tmp .= chr(hexdec(substr($hex, 4, 2)))
            . chr(hexdec(substr($hex, 2, 2)))
            . chr(hexdec(substr($hex, 0, 2)))
            . chr(0)
            . chr(0)
        ;
        $key = $this->md5_16($tmp);
        $this->ARC4_init(substr($key, 0, 10));
    }