This chapter presents the challenges of the data hiding methods, as well as the constraints linked to the structure of three-dimensional (3D) meshes, in particular its impact on the synchronization step. It describes a recent development, focused on a variety of different approaches. The chapter discusses the current situation and future areas of research in the field of 3D watermarking. It provides the preliminary notions concerning the aspects of watermarking in general, and the digital representation of 3D objects. Robust watermarking in a transformed domain requires a reversible preprocessing step that converts the meshes into coefficients in frequency space. Data hiding can be used as a secret communication tool. The chapter explains the possible improvements to be made in a 3D data hiding process.