A high capacity reversible data hiding scheme for encrypted covers based on histogram shifting

摘要

Reversible data hiding in encrypted domain has been discussed for years. However, the performance of the existing algorithms is generally not satisfactory for the difficulty in signal processing in encrypted domain. In this paper, a high capacity reversible data hiding scheme for encrypted covers is proposed. The cover is first partitioned into non-overlapping blocks and encrypted effectively with homomorphism but without data expansion. Then a histogram shifting algorithm based on prediction error extension is introduced to achieve high embedding capacity of the scheme. The parameters in embedding process can not only adjust the embedding rate but also provide pretty good support for the security of the embedded data. The algorithm can achieve full reversibility at high embedding rate without extra data, and the embedding rate can reach to 2 bpp (bit per pixel). The experimental results verify the effectiveness of our solution, and show that the proposed scheme has outstanding performance in both capacity and quality compared with similar algorithms. (C) 2019 Elsevier Ltd. All rights reserved.