A Progressive Threshold Secret Image Sharing with Meaningful Shares for Gray-Scale Image

摘要

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 secret sharing schemes have limitations of lossy recovery and pixel expansion for binary images, or complex computation and "All-or-Nothing" for greyscale images. In this paper, a novel progressive secret image sharing(PSS) scheme with threshold and lossless recovery is proposed to overcome these problems. Meanwhile, its meaningful shadows with the same size as secret are beneficial to identify and decrease the suspicion, and it can be directly applied to share grayscale images. Simulations show the advantages and effectiveness of the proposed scheme.