title: Secure information display with limited viewing zone by use of multi-color visual cryptography.
abstract: We propose a display technique that ensures security of visual information by use of visual cryptography. A displayed image appears as a completely random pattern unless viewed through a decoding mask. The display has a limited viewing zone with the decoding mask. We have developed a multi-color encryption code set. Eight colors are represented in combinations of a displayed image composed of red, green, blue, and black subpixels and a decoding mask composed of transparent and opaque subpixels. Furthermore, we have demonstrated secure information display by use of an LCD panel.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hayasaki
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nishida