The Dual Verifying VSS Scheme Based on Digital Signature and Halftone Logo

This study presents a novel scheme called a dual verifying (t, n) visual secret sharing scheme. In our proposed scheme, each participant receives a public key and an encrypted shadow instead of the original secret image through the public communication network. There are three goals achieved. The first is to generate a reconstructed secret image, which satisfies the general criteria high security, high quality image, low computational complexity, and no pixel expansion. This goal is achieved by high compression ratio, low complexity and good performance techniques in combination with Shamir´s scheme. The second goal is to confirm shadow authentication by applying a digital signature scheme. The last goal is to verify the reliability of the reconstructed secret image by using an extracted halftone logo. The halftoning transform in this proposed scheme is executed with an error diffusion technique to guarantee image luminance and to enhance the quality of the reconstructed image. Moreover, a reversible data embedding technique is adopted to make sure each shadow not only carries authentication information but also maintains a small shadow size.