Publication

Abstract : In Visual Cryptographic Scheme (VCS), the shares of the secret image are viewed as random whereas in Extended Visual Cryptographic Scheme (EVCS), the shares are viewed as meaningful images. When the number of participants increases the graying effect problem in deterministic VCS is caused due to high pixel expansion. This graying effect was resolved using ideal contrast constructions in VCS, but not in EVCS. In ideal contrast VCS; combinations of Boolean operations are used during reconstruction. Here in this paper, we designed a deterministic construction for access structure using the existing VCS constructions with contrast one as building block. In existing EVCS constructions the relative contrast will vary depending on the access structure, but in the proposed EVCS construction it is 0.25, which is better than existing schemes.