High-capacity reversible data hiding in encrypted images using dual-stage bit-plane compression and CP-ABE-based recovery authorization

Reversible data hiding in encrypted images (RDHEI) allows secret information to be concealed within encrypted images, and also enables the original image to be recovered accurately. However, existing reversible before encryption (RRBE) approaches do not effectively utilize bit-plane redundancy and typically offer limited support for fine-grained recovery authorization.

This research introduces a high-capacity RRBE-based RDHEI scheme that combines dual-stage bit-plane compression with block rearrangement. Additionally, a ciphertext-policy attribute-based encryption (CP-ABE)-based key encapsulation mechanism is introduced to facilitate fine-grained and policy-driven image recovery. The method begins by utilizing pixel predictors to produce compact prediction errors, then encodes consecutive all-zero high-order bit planes to exploit global sparsity, and further compresses the remaining bit planes using adaptive hierarchical block variable-length coding (AHBVLC) to capture local structural redundancy.

The compressible bit planes are then reorganized, and the image blocks are rearranged based on their embedding capacities. Experiments on BOSSBase, BOWS-2, and UCID datasets show that the proposed method achieves competitive embedding performance while allowing for exact recovery of the original image. The scheme also supports flexible, policy-driven image recovery in multi-user settings.

The authors acknowledge the valuable comments and suggestions from anonymous reviewers, and express gratitude for funding from the National Natural Science Foundation of China (Program No. 62272478). Collaborators include Shen Peng, Minqing Zhang, Yan Ke, Chao Jiang, and Juanli Sun from the College of Cryptography Engineering, Engineering University of PAP, Xi'an, China.

This article is licensed under a Creative Commons Attribution 4.0 International License, permitting use, sharing, adaptation, distribution, and reproduction in any medium or format, provided appropriate credit is given to the original author(s) and source, a link to the Creative Commons licence is included, and any changes made are noted.