Visual cryptography

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

XOR-based Region Incrementing Visual Cryptography Scheme with Share Block Construction

Abstract: ② (Science and Technology on Information Assurance Laboratory, Beijing 100072, China) Abstract: By designing the block construction for each share, which is divided into several blocks according to the number of qualified sets, the secret sharing and recovering algorithms of the XOR-based region incrementing visual cryptography are designed with the encoding matrices of the (n, n) XOR-based single secret sharing visual cryptography. Comparing with the existing schemes, the proposed scheme realizes the perfect recovery of decoded regions in secret image, and the sizes of shares are also decreased efficiently.

Plane-Wise Encryption Based Progressive Visual Cryptography for Gray Image

Abstract: Visual secret sharing is a powerful technique, which allows to diffuse and disguise a secret image into two or more shares. To reconstruct the secret image these shares are stacked and viewed by the human visual system. Unluckily, Visual cryptography is not in primary use because of the degradation process entails severe problems in reconstructed image quality. Degradation reflects in terms of pixel expansion and loss in contrast, which makes visual cryptography unsuitable to handle visual information (image, video etc.) for the purpose of sharing and protection. The visual secret sharing techniques performed computation in order to absolve reconstructed secret image from pixel expansion and loss in contrast. Progressive visual cryptography (PVC) inherits all the advantageous features of traditional visual cryptography except the decryption process. In PVC, contrast of the reconstructed secret image increases gradually as the number of stacked shares increase but quality of reconstructed secret images still an issue for the researchers. To resolve the issue, this paper proposes a plane-wise encryption based progressive visual cryptography scheme for gray image. The effectiveness of the proposed scheme are carried out by experimental results and compared with state of the art approaches. Experimental results show that proposed scheme is well suited for applications where quality of secret image is a major issue.

A Hybrid Visual Cryptography Method using Sigmoid Function for Security Enhancement in Gray Scale Images

Abstract: Visual encryption technology becomes the latest research area in which a lot of scopes persist. Presently such a particular cryptosystem procedure is now used by numerous other countries around the world for the private transmission of formal records, financial documents, content visuals, digital voting, and so on. Visualization Cryptographic algorithms one of the protected methods of transferring pictures online. The main benefit of image encryption has been that it disguises peripheral vision with encrypt data secret data with no computation usually needed. In this work a hybrid visual cryptography method using a sigmoid function (HVMSF) for enhancing the security in gray images. HVMSF strategy utilizes a chaos framework to scramble pixel values as well as blocks while using the Modified Arnold Cat Map method (MACM) as well as the Henon Map method (HMM). The methodology includes a confusion procedure wherein the location of each image pixel is shuffled by utilizing MACM. The shuffling of image pixel leads to the creation of a subset pixel which will be protected for transmitting. This proposed HVMSF mainly tries to overcome the limitation of the previous approaches by applying sigmoid function in image feature space for contrast enhancement throughout the consequent source images. The experimental outcomes precisely show that the suggested strategy can further give additional effectiveness to ensure the protection of transmitting information out over previous techniques.

Performance evaluation of a visual cryptography using halftone images

Abstract: Visual Cryptography is a secret sharing scheme which uses images distributed as shares such that, when the shares are superimposed, a hidden secret image is revealed. In extended visual cryptography, the shares images are constructed to contain meaningful cover images, thereby providing opportunities for integrating visual cryptography and biometric security techniques. In this paper, we propose a method for processing halftone images that improves the quality of the shares images and the recovered secret image in an extended visual cryptography scheme for which size of the shares images and the recovered image is the same as for the original halftone secret image. The resulting scheme maintains the perfect security of the original extended visual crypto grapy approach.

A Dynamic Security Model for Visual Cryptography and Digital Watermarking

Abstract: This paper proposes a model and algorithm for digital watermarking using visual cryptographic techniques. Initially the visual cryptographic techniques scrambled the secret information into pixelated form, this pixelated secret share does not reveal any key information. This pixelated secret shares are again embedded into invisible digital watermarking with separate covering image for each and every shares. A model and an Algorithm has been proposed based on this techniques, the result has been evaluated and the metrics also calculated. Moreover, our scheme shows better security features compared to the existing techniques.