Visual cryptography

About: Visual cryptography is a research topic. Over the lifetime, 1724 publications have been published within this topic receiving 25300 citations.

Pixel sieve method for secret sharing & visual cryptography

Abstract: Secret sharing and visual cryptography although they are two different type of cryptographic methods most of the time they are used together. In this paper a method is proposed which combines visual cryptography with secret sharing for encryption of visually represented information. The image is decrypted from the shares on the screen of the computer.

A Construction Method of (2, 3) Visual Cryptography Scheme

Abstract: Visual cryptography scheme (VCS) shares a binary secret image into multiple shadows, stacking qualified set of shadows will decode the secret image without computer resources. In this paper, we propose a (2, 3)-VCS, which can share one or two secret images into 3 shadows, stacking any two shadows will reveal the secret image. The shadow size is 3/2 times of the secret image. The contrasts of the revealed image are 1/3 and 1/2 when we share one and two secret images, respectively. We can also reveal the secret image by XOR decoding operation, and the visual quality of the revealed image can be further improved. By XOR decoding operation, the contrasts of the revealed image will be 2/3 and 1 when we share one or two secret images, respectively. In the case of sharing two secret images, the revealed two secret images have no distortion. Theoretic analysis and experimental results demonstrate the feasibility and advantages of the proposed (2, 3)-VCS.

Image protection based on visual cryptography and statistical property

Abstract: In this paper, a novel intellectual property protection scheme for digital images based on visual cryptography and statistical property is proposed. The result of comparing two pixels that are selected randomly from the host image determines the content of the master share. Then, the master share and the watermark are used to generate the ownership share according to the encryption rules of visual cryptography. Our method does not need to alter the original image and can identify the ownership without restoring to the original image. Besides, our method allows multiple watermarks to be registered for a single host image without causing any damage to other hidden watermarks. Moreover, it is also possible for our scheme to cast a larger watermark into a smaller host image. Finally, experimental results will show the robustness of our scheme against several common attacks.

An extensive review on visual cryptography schemes

Abstract: Visual Cryptography is a special kind of cryptographic technique in which the decryption can perform by the human visual capability. In general, for some critical security issue the visual cryptography scheme is used, for example to identify the difference in human and machine. Similarly some other applications also use the visual cryptography schemes like scanning and printing, captcha etc. Hence the researchers developed many methods and techniques for the visual cryptography schemes. This paper is intended to study the various visual cryptography schemes and also to analysis the performance on the basis of expansion of pixel, number of secret images, image format and type of share generated. In addition we present a concise description about the instructions for future research.