This paper proposes a watermarking method using homographs to protect copyright of CityGML file. This method creates an apparently identical document by selecting the part of the file that will embed the watermark, sorting by the numeric information there, and then modifying it with homographs. As a result of embedding and extracting watermark with the proposed method, it showed robustness against reordering attack and cropping attack.

CityGML, watermarking, homographs.