Topic
Visual cryptography
About: Visual cryptography is a research topic. Over the lifetime, 1724 publications have been published within this topic receiving 25300 citations.
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TL;DR: An advanced color covert image-sharing scheme using Arnold cat map (ACM) and VC that offers 3 levels of security and through decipherment gives back the covert image without loss of information is proposed.
TL;DR: The speckle pattern created by the scattered laser beam from rough surfaces is used for the first time in order to perform the visual secret sharing (visual cryptography), which is alternative material for random grid pattern.
Abstract: We used for the first time the speckle pattern created by the scattered laser beam from rough surfaces in order to perform the visual secret sharing (visual cryptography), which is alternative material for random grid pattern. Segmentation and binarization of the speckle pattern was performed for making one share embedding secret image. Reconstruction of the secret image was successfully achieved by the product between the share and the original speckle pattern.
11 Dec 2020
TL;DR: Based on two-dimensional lattices, a block halftone technology for a size-invariant VC is proposed in this paper, where the proposed block error diffusion takes a grayscale image as the input.
Abstract: Visual cryptography (VC) encodes a secret image into multiple transparencies. The secret image can be revealed by stacking a subset of these transparencies. However, the pixel expansion problem is a critical issue for VCs as a pixel in the secret image is encoded into multiple pixels. To solve this problem, many size-invariant VCs have been proposed. But there are some drawbacks in the existing size-invariant VCs. i) The input image is a binary image rather than a grayscale image. ii) Some schemes are not a ( $k, n$ ) - VC. iii) The quality of recovered image is poor. Based on two-dimensional lattices, a block halftone technology for a size-invariant VC is proposed. In particular, the proposed block error diffusion takes a grayscale image as the input. It is adaptable to any pixel expansion. The experiments show that the proposed halftone technique has a better visual quality for the stacking results than prior common schemes, such as probabilistic schemes.
Journal Article•
TL;DR: This work proposes a novel, simple and hard to decode (k, n) visual cryptography procedure which is used to successfully sharing the secret image with extreme concealment and uses permutation for n share, so that it becomes impossible for an outsider or attacker to decrypt the message encoded in an image.
Abstract: Visual Cryptography is an exceptional encryption technique to conceal information in images in such a way that it can be decrypted by the human visualization if the correct key image is utilized. Visual cryptography (VC) is a way of protecting the secret image which encodes the image into various shares and distributes them to various members. In k out of n (k, n) method, the secret image is allocated into n shares such that when k or more members by assembling their limpidity through an overhead projector to divulges the secret image. This work proposes a novel, simple and hard to decode (k, n) visual cryptography procedure which is used to successfully sharing the secret image with extreme concealment. We have used permutation for n share, so that it becomes impossible for an outsider or attacker to decrypt the message encoded in an image.
TL;DR: A novel visual cryptography scheme is offered that encodes a colour secret image into two meaningful shares that keeps the image from the attention of possible attackers during the transmission.
Abstract: Visual cryptography is a useful technique for sharing secret information on a public channel. One of the major strengths of visual cryptography is that the hidden secret, once extracted, can be visualized by the human eye without going through complex computations for decoding. In this paper, a novel visual cryptography scheme is offered that encodes a colour secret image into two meaningful shares. Our proposal provides improvements that allow the size of the meaningful share to stay fixed. This keeps the image from the attention of possible attackers during the transmission. In addition, our new scheme provides three patterns which produce better visual equality for each meaningful share. It also allows a user to produce a different secret image/share with the desired visual effects. Experimental results have demonstrated the practicability and effectiveness of our new scheme.