EXTENDED VISUAL CRYPTOGRAPHY SCHEME FOR COLOR IMAGES WITH NO PIXEL EXPANSION

2010 ◽  
Keyword(s):  
Visual Cryptography ◽  
Color Images ◽  
Pixel Expansion ◽  
Visual Cryptography Scheme

scholarly journals VISUAL CRYPTOGRAPHY FOR COLOR IMAGES

2013 ◽  
pp. 147-149
Author(s):  
ASHWATHIMESANGLA AO
Keyword(s):  
Secret Sharing ◽  
Visual Cryptography ◽  
Color Images ◽  
Secret Sharing Scheme ◽  
Secret Image ◽  
Secret Information ◽  
Host Image ◽  
Sharing Scheme ◽  
Visual Cryptography Scheme

Visual cryptography is a secret sharing scheme for encrypting a secret image, it is a perfectly secure way that allows secret sharing without any cryptographic computation, which is termed as Visual Cryptography Scheme (VCS). In this paper secret image is divided into shares (printed on transparencies), and each share holds some information. At the receiver this shares are merged to obtain the secret information which is revealed without any complex computation. The proposed algorithm is for color host image, divided into three color planes Red, Green, Blue and merged with secret image which is binarized and divided into shares. The decoding requires aligning the result obtained by merging color host image and shares, so as to obtain the secret image.

On the Pixel Expansion of Visual Cryptography Scheme

2017 ◽  
Vol 9 (2) ◽  
pp. 38-44 ◽  
Author(s):  
Teng Guo ◽  
Jian Jiao ◽  
Feng Liu ◽  
Wen Wang
Keyword(s):  
Visual Cryptography ◽  
Upper Bounds ◽  
Graph Decomposition ◽  
Decomposition Technique ◽  
Pixel Expansion ◽  
Access Structures ◽  
Visual Cryptography Scheme ◽  
Graph Access

In this paper, we first follow Ateniese et al.'s work that provides upper bounds of the pixel expansion of visual cryptography schemes(VCSs) for more kinds of graph access structures, in which we require that a subset of parties can determine the secret if they contain an edge of the graph G. The constructive upper bounds are derived by the graph decomposition technique. Then we generalize Ateniese et al.'s method of comparing the optimal pixel expansion of VCSs with two different access structures.

scholarly journals On the security of a visual cryptography scheme for color images

2009 ◽  
Vol 42 (5) ◽  
pp. 929-940 ◽  
Author(s):  
Bert W. Leung ◽  
Felix Y. Ng ◽  
Duncan S. Wong
Keyword(s):  
Visual Cryptography ◽  
Color Images ◽  
Visual Cryptography Scheme

scholarly journals Correction to: An Approach for Visual Cryptography Scheme on Color Images

2020 ◽  
pp. C1-C1
Author(s):  
Pooja Kashyap ◽  
Binita Rai ◽  
Chinmoy Kar ◽  
Suman Kalyan Kar ◽  
Sreeparna Banerjee
Keyword(s):  
Visual Cryptography ◽  
Color Images ◽  
Visual Cryptography Scheme

scholarly journals An optimization of color halftone visual cryptography scheme based on Bat algorithm

2021 ◽  
Vol 30 (1) ◽  
pp. 816-835
Author(s):  
Firas Mohammed Aswad ◽  
Ihsan Salman ◽  
Salama A. Mostafa
Keyword(s):  
Visual Information ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Visual Cryptography ◽  
Visual Quality ◽  
Bat Algorithm ◽  
Pixel Expansion ◽  
Low Contrast ◽  
Secret Image ◽  
Visual Cryptography Scheme

Abstract Visual cryptography is a cryptographic technique that allows visual information to be encrypted so that the human optical system can perform the decryption without any cryptographic computation. The halftone visual cryptography scheme (HVCS) is a type of visual cryptography (VC) that encodes the secret image into halftone images to produce secure and meaningful shares. However, the HVC scheme has many unsolved problems, such as pixel expansion, low contrast, cross-interference problem, and difficulty in managing share images. This article aims to enhance the visual quality and avoid the problems of cross-interference and pixel expansion of the share images. It introduces a novel optimization of color halftone visual cryptography (OCHVC) scheme by using two proposed techniques: hash codebook and construction techniques. The new techniques distribute the information pixels of a secret image into a halftone cover image randomly based on a bat optimization algorithm. The results show that these techniques have enhanced security levels and make the proposed OCHVC scheme more robust against different attacks. The OCHVC scheme achieves mean squared error (MSE) of 95.0%, peak signal-to-noise ratio (PSNR) of 28.3%, normalized cross correlation (NCC) of 99.4%, and universal quality index (UQI) of 99.3% on average for the six shares. Subsequently, the experiment results based on image quality metrics show improvement in size, visual quality, and security for retrieved secret images and meaningful share images of the OCHVC scheme. Comparing the proposed OCHVC with some related works shows that the OCHVC scheme is more effective and secure.

scholarly journals A New Bi-Level Encoding and Decoding Scheme for Pixel Expansion Based Visual Cryptography

2019 ◽  
Vol 6 (1) ◽  
pp. 18-42
Author(s):  
Ram Chandra Barik ◽  
Suvamoy Changder ◽  
Sitanshu Sekhar Sahu
Keyword(s):  
Information Security ◽  
Secret Sharing ◽  
Visual Cryptography ◽  
Color Images ◽  
Secret Sharing Scheme ◽  
Normal Vision ◽  
Visual Secret Sharing ◽  
Pixel Expansion ◽  
Host Image ◽  
Sharing Scheme

Mapping of image-based object textures to ASCII characters can be a new modification towards visual cryptography. Naor and Shamir proposed a new dimension of Information security as visual cryptography which is a secret sharing scheme among N number of participants with pixel expansion. Later on, many researchers extended the visual secret sharing scheme with no expansion of pixel regions in binary and color images. By stacking k shares the secret can be decoded using normal vision. In this paper the authors have proposed a modification towards visual cryptography by converting the message in the form of printable ASCII character-based numerical encoding patterns in a binary host image. The encoding of the message is represented as ASCII numeric and a texture of those numeric are arranged to form a binary host image. Then, N numbers of shares are built up but after stacking all the shares the decoding of the message is achieved by converting ASCII numeric to the secret.

Multi-Secret Sharing Visual Cryptography Scheme Based on XOR Algorithm

2014 ◽  
Vol 644-650 ◽  
pp. 2108-2111 ◽  
Author(s):  
Yan Yan Ha ◽  
Shuai Ji ◽  
Wen Cai He ◽  
Yao Zhang
Keyword(s):  
Secret Sharing ◽  
Visual Cryptography ◽  
Pixel Expansion ◽  
Visual Cryptography Scheme ◽  
Multi Secret Sharing ◽  
Multiple Secret Images

XOR algorithm can be used to improve the recovery effects of visual cryptography scheme. In this paper, we present a multi-secret visual cryptography scheme by using the matrices of the (k, k)-VCS. We can reveal multiple secret images perfectly by the XOR algorithm and shifting operation on the shares. The visual qualities of recovered images are ideal without any pixel expansion.

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