Tamper Proofing 3D Models

This paper describes a novel algorithm designed for tamper proofing of 3D models. Fragile watermarking is a known technique for detecting location of tamper in the artwork. However, to detect even minute changes, the watermark needs to be distributed throughout the 3D model. This poses as a challenge since watermarking all vertices can cause perceptible distortion. The proposed algorithm solves this problem by inserting a watermark in all the vertices of a 3D model. The watermark is randomly added to each and every vertex of the 3D model by modifying the coordinate location of the vertices. Genetic Algorithms have been used to find the near optimal coordinate location of the watermarked vertex. The fitness function chosen is the Signal to Noise Ratio of the 1-ring neighbourhood of the vertex. This ensures that there exists no distortion in the watermarked model. The proposed approach is computationally inexpensive and experimental results indicate that the algorithm can efficiently detect location of any kind of unauthorized data modification.