Binary-block embedding for reversible data hiding in encrypted images

This paper first introduces a binary-block embedding (BBE) method to embed secret data in a binary image. Using BBE, we propose an algorithm for reversible data hiding in encrypted images (BBE-RDHEI). It uses BBE to embed binary bits in lower bit-planes of the original image into its higher bit-planes such that the lower bitplanes can be reserved for hiding secret data in subsequent processes. BBE-RDHEI employs a bit-level scrambling process after secret data embedding to spread embedded secret data to the entire marked encrypted image so that it can prevent secret data from loss. A security key design mechanism is proposed to enhance the security level of BBE-RDHEI. The processes of BBE-RDHEI are fully reversible. The secret data and original image can be reconstructed independently and separately. Experiments and comparisons show that BBERDHEI has an embedding rate nearly twice larger than the state-of-the-art algorithms, generates the marked decrypted images with high quality, and is able to withstand the brute-force, differential, noise and data loss