Image Secret Sharing and Hiding with Authentication

Recently, Lin-Tsai, Yang et al., and Chang et al. proposed image secret sharing and hiding schemes with authentication. The secret image is shared and hided into ordinary cover images to form the stego images so as to be transmitted securely. Unfortunately, there is a common weakness that each stego image should be expanded to 4 times of the secret image. In this paper, we propose an enhanced (t, n) threshold scheme with smaller size expansion of the stego images. The size of each stego image is reduced to 3.5/t times of the secret image with the image quality better than the previous schemes. In addition, the authentication property is improved based on hash function. Finally, the experimental results show that our scheme is superior to the compared schemes.