Reversible data hiding in encrypted images with block-based adaptive MSB encoding

Abstract

Contemporary cloud storage and social media networks have matured and; as a result, the privacy protection of image content in these applications have attracted more attention. Reversible data hiding in encrypted images (RDHEI) is an efficient technique to embed additional data such as timestamps, watermarks, and copyright information into encrypted images to protect the image content. This paper proposes a reversible data hiding scheme in encrypted images based on a block-based adaptive MSB encoding technique (BAME-RDHEI). The content owner first uses a block-based image encryption method, including block permutation, pixel permutation in each block, and the block-based bitwise exclusive-or operation, to encrypt an image. This specific image encryption method preserves the relevance of the MSB bit planes in each block, and the block-based adaptive MSB encoding technique can be applied to classify and encode eight block types according to the number of MSB bit planes where all the values are all ‘1’ or ‘0’. After embedding the indicators that are generated by Huffman coding into the first MSB bit plane of each block, the remaining values of these MSB bit planes can be vacated for data embedding. The receiver can extract additional data, decrypted the image or recover the original image according to the different keys. The experimental results demonstrate that our proposed scheme provides enhanced security, significantly improves the embedding rate, and obtains higher visual quality for the decrypted image compared to other state-of-the-art schemes.