High-Capacity Reversible Data Hiding in Encrypted Images with Flexible Restoration

Abstract

In this paper, we propose a novel reversible data hiding in encrypted images (RDH-EI) method that achieves the highest hiding capacity in the RDH-EI research field and full flexibility in the processing order without restrictions. In the previous work in this field, there exist two representative methods; one provides flexible processing with a high hiding capacity of 2.17 bpp, and the other achieves the highest hiding capacity of 2.46 bpp by using the BOWS-2 dataset. The latter method has critical restrictions on the processing order. We focus on the advantage of the former method and introduce two efficient algorithms for maximizing the hiding capacity. With these algorithms, the proposed method can predict each pixel value with higher accuracy and refine the embedding algorithm. Consequently, the hiding capacity is effectively enhanced to 2.50 bpp using the BOWS-2 dataset, and a series of processes can be freely conducted without considering any restrictions on the order between data hiding and encryption. In the same way, there are no restrictions on the processing order in the restoration process. Thus, the proposed method provides flexibility in the privileges requested by users. Experimental results show the effectiveness of the proposed method in terms of hiding capacity and marked-image quality.

A Novel Reversible Data Hiding Algorithm Based on Enhanced Reduced Difference Expansion

“…where = d i is the result of the difference value after te embedding process, and b i is the secret data, and b i ∈ (0, 1,2,3) Step 7. The new vector u i is updated by using Equation (9).…”

“…In contrast, a reversible data-hiding (RDH) scheme can extract the secret data and recover the original cover images in the extracting process. In recent years, RDH schemes have received much attention from the research community [2][3][4][5]. RDH schemes are suitable in some sensitive scenarios, such as military, medical and forensic fields, where any permanent distortion is unacceptable, and the exact recovery of the original cover data is required.…”

Reversible data hiding algorithm in encrypted images using adaptive total variation and cross-cyclic shift

“…In some public cloud storage applications, the content owner of multimedia data may not trust the information hiding party, which requires the content owner to encrypt the original data before uploading the data. Therefore, to facilitate the management of users' encrypted data, data managers want to hide information in the encrypted data, and reversible data hiding technology in encrypted images (RDHEI) has emerged (Arai and Imaizumi, 2022;Ge et al, 2023;Rai et al, 2023). Unlike traditional RDH technology, RDHEI technology can extract secret information without decryption.…”