Adopting secret sharing for reversible data hiding in encrypted images

Secret sharing is an alternative method for protecting an image by dividing it into multiple encrypted shares. When sufficient shares are collected, the image can be losslessly recovered. In this paper, secret sharing is adopted to reversible data hiding in encrypted images. A basic model by using secret sharing for reversible data hiding in encrypted images is firstly introduced. Then, an image encryption algorithm by using Shamir's secret sharing is proposed. Theoretical analysis is provided for substantiating that the shares generated by the proposed encryption algorithm are suitable for data embedding. Finally, two basic methods by using difference expansion and difference histogram shifting are given, as well as some extensions. Experimental results are demonstrated, illustrating the merits of the proposed methods such as low computational complexity, high embedding capacity and real reversibility are achieved.