A user-friendly secret image sharing scheme with reversible steganography based on cellular automata

Abstract

Secret image sharing is a mechanism to protect a secret image among a group of participants by encrypting the secret into shares and decrypting the secret with sufficient shares. Conventional schemes generate meaningless shares, which are hard to identify and lead to suspicion of secret image encryption. To overcome these problems, sharing schemes with steganography were presented. The meaningless shared data were embedded into the cover image to form stego images. However, distorted stego images cannot be reverted to original. In this work, a novel secret image sharing scheme with reversible steganography is proposed. Main contribution of this work is that two-dimensional reversible cellular automata with memory is utilized to encrypt a secret image into shared data, which are then embedded into cover image for forming stego images. By collecting sufficient stego images, not only the secret image is lossless reconstructed, but also distorted stego image is reverted to original. Simulation results shows that low computation cost and pleasing stego image quality are also achieved by the proposed scheme.