This figure shows an experiment for visual authorization. In this experiment, the size of authorization set is 3, shown in (a) to (c). The graytone versions of the key-share and user-share are shown in (d) and (e), respectively. The produced key-share is shown in (f), and three binary user-shares, (g) to (i), to take account of the three authorities defined in the authorization set. One can see that, except carefully examining the pixel distributions of these images, these images are visually indistinguishable. However, the superposed images of these key-shares with the key-share are quite different, as shown in (j) to (l).
(2,2) access schemes of visual cryptography
1. Plain Shares
S1 and S2 are plain images. Superposing S1 and S2 will reveal the secret information (S1+S2). The image shown in S1+S2 is the halftone version of Target image.
S1 and S2 are meaningful images. Superposing S1 and S2 will reveal the secret information (S1+S2). The image shown in S1+S2 is the halftone version of Target image.
general access schemes of visual cryptography