  Reversible data hiding in encrypted domain (RDH-ED) has received tremendous
attention from the research community because data can be embedded into cover
media without exposing it to the third party data hider and the cover media can
be losslessly recovered after the extraction of the embedded data. Although, in
recent years, extensive studies have been carried out about images based
RDH-ED, little attention is paid to RDH-ED in 3D meshes due to its complex data
structure and irregular geometry. In this paper, we propose a separable RDH-ED
method for 3D meshes based on integer mapping and Multi-MSB (multiplication
most significant bit) prediction. The proposed method divides all the vertices
of the mesh into the "embedded" set and "reference" set, and maps decimals of
the vertex into integers. Then, we calculate the Multi-MSB prediction errors
for the vertices of the "embedded" set and a bit-stream encryption technique
will be executed. Finally, additional data is embedded by replacing the
Multi-MSB of the encrypted vertex coordinates. According to different
permissions, recipient can obtain the original plaintext meshes, additional
data or both. Experimental results show that the proposed method has higher
embedding capacity and higher quality of the recovered meshes compared to the
state-of-art methods.
