No abstract

Visual cryptographic scheme (VCS) has an attractive property of decoding that can be performed directly by the human visual system without any computation. This novel stacking-to-see property of VCS can be secure and cheap used for visual authentication in accessing a data base. In this paper, we design a new participantspecific VCS (PSVCS) to extend the authentication scenario from a single-client authentication in VCS-based authentication schemes to a group of clients with specific threshold property. The proposed (t; k; n)-PSVCS, where t k n, needs t specific participants and other (k À t) participants to decode the secret image. When compared with previous VCS-based authentication schemes, our PSVCS-based authentication can provide different privileges to clients and is more suitable for real environment.