Affine-Transformation-Invariant Public Fragile Watermarking for 3D Model Authentication

We propose a transformation invariant public fragile watermarking scheme for 3D model authentication. The proposed scheme embeds watermarks in a subset a model´s faces to keep them in a predefined relationship with neighboring vertices so that any changes will ruin the relationship between the mark faces and neighboring vertices. The proposed scheme has the following advantages: it is invariant to translation, rotation, and uniform scaling operations. These operations do not change the integrity of the original model and should not be regarded as malicious attacks. The proposed method is public- the receiver does not need the original model and watermarks for authentication. It can locate changed regions. Distortion caused by the watermark embedding is controlled by the key settings according to the users´ precision requirement. Experimental results show the scheme´s effectiveness.