Flexible Visual Cryptography Scheme and Its Application

TLDR: Two visual cryptography schemes which simulated the principle of fountains are proposed which are more general and simpler, real flexible and has competitive visual quality for the recovered secret image.

Abstract: For visual cryptography scheme (VCS), normally, the size of the recovered secret image will be expanded by m( ≥ 1) times of the original secret image. In most cases, m is not a square number, hence the recovered secret image will be distorted. Sometimes, m is too large that will bring much inconvenience to the participants to carry the share images. In this paper, we propose two visual cryptography schemes which simulated the principle of fountains. The proposed schemes have two advantages: non-distortion and flexible (with respect to the pixel expansion). Furthermore, the proposed schemes can be applied to any VCS that is under the pixel by pixel encryption model, such as VCS for general access structure, color VCS and extended VCS, and our VCS does not restrict to any specific underlying operation. Compared with other non-distortion schemes, the proposed schemes are more general and simpler, real flexible and has competitive visual quality for the recovered secret image.