A New Scheme to Hide the Data Integrity Marker on Vector Maps using A Feature-Based Fragile Watermarking Algorithm

For vector maps, obtaining precise locations to hide the data integrity marker with existing fragile watermarking algorithms is technically challenging. Using a fragile watermarking technique based on a LSB data insertion, a feature-based fragile watermarking algorithm that inserts watermark for each feature and detects the tampered features with high accuracy was proposed. In the proposed algorithm, the watermark calculation used the hash function for each feature as the data integrity marker, and generated new vertices on the feature to embed the watermarks. While the insertion watermark for each features ensures superior precision of location to verify the data integrity on the map, the proposed algorithm also maintains the original content the map. The invisibility test showed good results, demonstrated by RMSE values close to zero. This scheme produces a distortion watermarked map on a scale of 10(-7) - 10(-8) meter in the real world. This characteristic is influenced by the precision parameter and number of digit LSB insertion. The experimental results also shows that the proposed algorithm can detect attacks such as vertex/feature modification, vertex/feature addition, and vertex/feature deletion. A consequence of the algorithm is an increasing in file size of the watermarked maps, but in a range less than 200%.