Reversible Data Hiding In Encrypted Images by Reserving Room before Encryption

Abstract Recently, more and more attention is paid to reversible data hiding (RDH) in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content’s con?dentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may subject to some errors on data extraction and/or image restoration. Here, a novel method is proposed so as to reserve room before encryption with a traditional RDH algorithm, and thus it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, i.e., data extraction and image recovery are free of any error.