Improved Scheme for Reversible Data Hiding for Encrypted Images using Interpolation Technique

Abstract

Aiming at avoiding the leakage of image contour and that the embedding capacity can be adjusted by the data hider, this paper improves an interpolation-based reversible data hiding scheme in encrypted images (RDH-EI). Before image encryption, we create the embedding space for encrypted image in interpolation-errors of non-sample pixels, using the interpolation techniques. The generated auxiliary data is embedded into the sample pixels with classical difference expansion (DE) technique. Then, a stream cipher is utilized to encrypt sample pixels, and a scrambling encryption is utilized to encrypt interpolation-errors of non-sample pixels to preserve the histogram of interpolation-errors. On the cloud server, the data hider can embed additional data into interpolation-errors with expansion and shifting simply. As a result, an authorized receiver can extract embedding data exactly and recover the original image perfectly, and the two operations are separable. Experimental results also indicate the effectiveness of the proposed method.