On improving homomorphic encryption-based reversible data hiding

Abstract

Reversible data hiding for encrypted images with improved performance is introduced in this paper. Each unit in the original image is separated into three components, and each component is encrypted by Paillier homomorphic encryption. Additional bits can be concealed into the encrypted image by manipulating the encrypted signals. Finally, the original image is obtained without error when the direct decryption is applied. The embedded bits are perfectly extracted as well. Optimal visual quality and improved embedding rate are obtained by the proposed approach, since the value of the directly decrypted unit is the same as the original one. Experimental results and comparisons are demonstrated to illustrate the effectiveness and advantages of the proposed method.