A Fully Reversible Data Hiding Scheme in Encrypted Images Based on Homomorphic Encryption and Pixel Prediction

摘要

Reversible data hiding in encrypted images (RDHEI) is a widely used technique for privacy protection, which has been developed in many applications that require high confidentiality, authentication and integrity. Proposed RDHEI methods do not allow high embedding rate while ensuring losslessly recover the original image. Moreover, embedding computational complexity and embedding rate are not satisfactory when using public key encryption-based methods. This paper proposes a new fully reversible method based on Paillier homomorphic cryptosystem and pixel prediction. We use gradient adjust prediction to obtain redundant space in the original image and embed secret information with homomorphic operation after encryption. Experimental results show that our scheme can achieve high capacity (near 0.95 bpp) and can losslessly recover the original images with peak signal to noise ratio of +infinity and structural similarity of 1. Compared with proposed reversible data hiding algorithms, our scheme has a significant improvement in reconstructing quality, safety and capacity.