Reversible data hiding scheme for encrypted JPEG bitstreams using adaptive RZL rotation

Joint Photographic Experts Group (JPEG) format is extensively used for images in many practical applications due to its excellent compression ratio and satisfactory image quality. Considering compelling concerns about the invasion of privacy, this paper proposes an effective reversible data hiding scheme for encrypted JPEG bitstreams, to provide security and privacy for both secret messages and valuable carriers. First, a format-compatibility and file size preserving encryption algorithm is applied to encipher the plaintext JPEG image into a noise-like version. Then, we present an effective reversible data hiding scheme in encrypted JPEG bitstreams using adaptive RZL rotation, where the secret messages are concealed with the sequence of RZL pairs. When the authorized user receives the marked encrypted JPEG bitstreams, the error-free extraction of secret messages and the lossless recovery of the original plaintext JPEG image can be accomplished separately. Extensive experiments are conducted to show that, compared to some state-of-the-art schemes, the proposed scheme has a superior performance in terms of embedding capacity, while keeping file size preservation and format compatibility.