A Fragile Digital Watermark Used to Verify the Integrity of Vector Map

The methods of integrity authentication for vector maps were described at fist, then digital watermarking for vector data was introduced. Finally, a fragile watermark algorithm for vector maps was proposed, which was based on that the vector map was divided into a series of blocks, and watermark information was embedded in these blocks. The extraction procedure not only verifies the integrity of the watermarked vector map, but also locates modification. The watermarked vector map can be used for its data is modified slightly, and the original vector map can be restored by extraction procedure for special application.