Reversible data hiding in encrypted images using interpolation-based distributed space reservation

Reversible data hiding (RDH) in encrypted images has attained more attention recently in research community. Privacy protection of additional data as well as cover media makes it attractive for applications in medical imaging, cloud storage, forensics etc. In this paper, a new method for reversible data hiding in encrypted images (RDH-EI), is proposed. Our method adopts the approach of reserving sufficient space for the additional data before encrypting the cover image. First we identify suitable blocks for hiding data from various parts of the image. Before encrypting the image, one or more LSB-planes of these blocks are backed-up into remaining parts of the image using a high-performing traditional RDH method that works on unencrypted images. After encrypting the image, those LSB-planes are used to hide additional data. Recovery of original cover image and error-free extraction of additional data is guaranteed always. Moreover, the proposed method is simple and intuitive. Experimentally results show that our method outperforms the state-of-the-art methods for reversible data hiding in encrypted images.