Selective authentication algorithm based on semi-fragile watermarking for vector geographical data

Unlike the exact authentication, selective authentication only needs to provide the detection and location of significant revision. So, some subtle modification is allowed in some practical applications, such as data compression. Selective authentication can identify whether or not data is still useful after being modified. The purpose of this paper is to propose a selective authentication algorithm based on semi-fragile watermarks for vector geographical data. The proposed scheme simplifies the map by using the Douglas Peucker algorithm to obtain the feature points. First, the relationship between selective authentication and semi-fragile watermarking is analyzed. Then, the feature points are obtained by the Douglas Peucker algorithm. Furthermore, the feature points and non-feature points are embedded using different watermark embedding, detection and authentication rules. The experimental results indicate that the proposed algorithm has good invisibility, and is robust to compression, addition of noise, and deletion of points. Besides, the maximum watermarking error can be strictly controlled. The proposed algorithm can better meet the needs of the selective authentication for vector geographical data.