On the Analysis and Design of Visual Cryptography With Error Correcting Capability

A ( k, n) visual cryptographic scheme (VCS) shares a secret image into n shadow images that are distributed over n involved participants. When k participants stack their shadow images, the secret is revealed. The secret image of VCS is a visual secret. Even though black/white dots in shadows suffer from interference by noise, the color may still retain the corresponding darkness with high probability. Therefore, VCS has noise immunity for secret recovery. Hence, it seems that there is no need to design a VCS that is robust to noise interference when transmitting or storing the files of shadow images. However, some VCSs use the permutations of subpixels in shadow images as information to realize multiple decoding options. For such schemes, we absolutely should ensure the correctness of the shadows. In this article, we investigate a VCS with t-error correcting capability (VCS- tEC). To the best of our knowledge, VCS- tEC is introduced for the first time. Three ( k, n)-VCS- tEC schemes are proposed: the separated scheme, the integrated scheme, and the nonsystematic scheme.