public function toKdbx(iKey $key, $filter, &$error)
	{
		$kdbx = KdbxFile::createForEncrypting(self::ROUNDS, $error);
		if($kdbx == null)
			return null;

		$this->_headerHash = $kdbx->getHeaderHash();

		$json = $this->toJSon($filter, $error);
		if(empty($json))
			return null;

		return $kdbx->encrypt($json, $key, $error);
	}