Reversible data hiding in encrypted images using block-based adaptive MSBs prediction

Abstract

This paper proposes a reversible data hiding method in encrypted images with a high embedding capacity. In the proposed method, the original image is encrypted using a block-level encryption algorithm based on a chaotic system, which protects the privacy of the original image while maintaining some redundancy of the encrypted image block. For each encrypted block, the data hider first evaluates the embedding capacity based on the accuracy of the most significant bit (MSB) prediction. Then, the data is embedded into every encrypted image block by adaptive-layer MSB substitution. At the receiving side, the receiver first extracts the data from the marked encrypted image and recovers the encrypted image by block-based MSB prediction. Then, the secret message can be obtained with the data hiding key, and the original image can be perfectly reconstructed with the encryption key. Experimental results and analysis show that the embedding capacity is significantly improved.