Reversible Data Hiding in Encrypted Three-Dimensional Mesh Models

Reversible data hiding in encrypted domain (RDH-ED) has greatly attracted researchers as the original content can be losslessly reconstructed after the embedded data are extracted, while the content owner's privacy remains protected. Most of the existing RDH-ED algorithms are designed for grayscale/color images, which cannot be directly applied to other carriers, such as three-dimensional (3D) meshes. With the rapid development of 3D related applications, 3D models have been widely used on the Internet, which motivated us to design a reliable RDH-ED scheme for 3D meshes. The proposed method maps decimals of the vertex coordinates into integers first, so that a bit-stream encryption technique can be executed. With a data-hiding key, several least-significant bits are operated to embed data. By using the encryption key, a receiver can roughly reconstruct the content of the mesh. According to the data-hiding key, with the aid of spatial correlation in natural mesh models, the embedded data can be successfully extracted and the original mesh can be perfectly recovered. Experiments show that the proposed method has a high data-embedding payload, maintains high values of the decrypted meshes, and has low computational complexity.