protected static function _secureDelete($file)
    {
        if (isset($ptr['secure'][$file])) {
            $filesize = filesize($file);
            $fp = fopen($file, 'r+');
            foreach (self::$patterns as $pattern) {
                $pattern = substr(str_repeat($pattern, floor($filesize / strlen($pattern)) + 1), 0, $filesize);
                fwrite($fp, $pattern);
                fseek($fp, 0);
            }
            fclose($fp);
        }

        @unlink($file);
    }