Reversible Data Hiding in Encrypted Images Using Reservoir Computing-Based Data Fusion Strategy

Reversible data hiding in encrypted image (RDHEI) is a powerful security technology that aims to hide data into the encrypted image without any distortions of data extraction and image recovery. Most existing RDHEI methods using vacated room-based data embedding algorithms face challenges in improving embedding capacity and security. In this paper, we develop a novel data hiding strategy via fusion based on reservoir computing (RC) system, upon which a new RDHEI scheme is further proposed. In the proposed scheme, the original image is first encrypted by the stream cipher-based encryption algorithm using the secret keys generated by an optical chaotic system. Then, by means of the RC system, the generated encrypted image can be fused with the secret data to produce the final masked image. Unlike the existing data embedding algorithms based on vacating rooms, the RC-based fusion strategy allows for hiding secret data comparable to the volume of the cover image into the encrypted image so that a higher embedding capacity can be greatly afforded. Moreover, the proposed strategy involves a chaotic transformation via the reservoir of RC system during data hiding, producing a masked image that is completely different from the encrypted image, thus the security is greatly enhanced. Experimental results show the contributions in improving the embedding capacity and security, and also demonstrate the superiority of the proposed scheme compared to some existing RDHEI methods.