An (n, n) threshold visual cryptography scheme for cheating prevention

In this paper, we propose an (n, n) threshold visual cryptography scheme for cheating prevention to improve the generic transformation for cheating prevention scheme (GTCP). We analysis the cheating problem in the GTCP, and present the cheating method applied it to attack on the GTCP. Then we construct the matrices for cheating prevention with following features: (a) each participant can´t gain any useful information from his shares, (b) each pixel has the same number of black and white subpixels in the secret share and in the verification share, (c) one´s verification image will be recovered by stacking of his verification share and the secret share, (d) the secret image can be revealed by stacking all the secret shares. The analysis showed that our scheme can avoid cheating.