Multilevel Visual Secret Sharing

This paper presents a novel visual secret sharing (VSS) scheme, called the multilevel VSS scheme, for sharing multiple visual secrets in an image among n participants. In the proposed n-level VSS scheme, the content of an image S is distributed to n levels of secrecy, and encoded to n+1 shares that exhibit the following features: (a) each share does not reveal any secret in S, (b) any k (2 les k les n+1) shares can be used to reveal k-1 levels of secrecy, (c) all secrets in S can be disclosed when all of the n+1 shares are available and (d) the secrets are revealed by visual inspection of the appropriately stacked shares without any computation.