Visual secret sharing with meaningful shares

A conventional k out of n visual cryptographic scheme ((k, n)-VCS) encodes one secret image P into n random-looking transparencies (called shares) such that any group of k or more transparencies reveals P to our eyes when they are superimposed, while that of less than k ones cannot. Given one secret image P and one cover image C, we study (k, n)-VCS with meaningful shares in this paper where shares could be recognized as the meaningful C (instead of random pictures) and their superimpositions follow the requirements of (k, n)-VCS. We present a formal definition and develop an efficient construction for (k, n)-VCS with meaningful shares. Experimental results demonstrate the effectiveness of our construction.