A Novel Visual Cryptography Scheme with Different Importance of Shadows

摘要

Traditional (k, n) visual cryptography scheme (VCS) encrypts a secret image into n shadows. Any k or more shadows can be printed on transparences and stacked together to reveal the secret image, while any k-1 or less shadows cannot get any information about the secret image. Most of the previous VCSs do not distinguish the importance of shadows. In this paper, we propose a novel (t, s, k, n) essential and non-essential visual cryptography scheme (ENVCS) with different importance of participants. According to the concept of constructing VCS from smaller schemes, we construct the basis matrices for (t, s, k, n)-ENVCS by concatenating the basis matrices of these smaller schemes. The constructed (t, s, k, n)-ENVCS is also progressive VCS. Experiments and analyses are conducted to verify the security and efficiency of the proposed method.