Due to the property that coverless image steganography can hide secret information without modifying the carrier, it has the ability to resist the existing steganalysis tools effectively. However, with the continuous development of new media and the increasing complexity of application scenarios, finding a more se-cure means of covert communication has become an urgent problem. In this paper, we propose a 3D coverless image steganography (3D-CIS) method. Based on the properties of 3D image and the relationship between 2D image and 3D image, the...