AN EXTENDED CONSTRUCTION METHOD FOR VISUAL SECRET SHARING SCHEMES

A visual secret sharing scheme [1] permits a secret to be shared among participants using transparencies. In this paper, we consider an exte nded scheme for visual secret sharing. We propose an improved method o f constructing the visual secret sharing scheme that can conceal some images in a series of transparencies, in such a way that different ima ges are seen as the number of stacking transparencies increases. Furth ermore, we describe applications of the visual secret sharing scheme t o copy machines and human identification schemes. In the identificatio n scheme, users recognize messages from an identification terminal by stacking their transparencies on the display. A great advantage of thi s scheme is that users can validate the authenticity of the terminal w ithout consulting a computer or calculator. (C) 1998 Scripta Technica.