An Improved Visual Cryptography Scheme for Secret Hiding

International Journal of Computer Applications

In today's world handling and security of information from attacks becomes very important aspect for the individuals. Researchers are innovating new techniques to secure the information from unwanted intrusions. Various cryptography techniques are discovered and many are yet to be revealed. Here in this paper we are going to review an advanced method of information hiding i.e. Visual Cryptography. Visual Cryptography emerged as a special encryption technique for information hiding using images. In way that encrypted image can be decrypted by the human vision if the correct image key is used. By this cryptographic technique we can encrypt visual information (pictures, text, etc.) in a way that human visual system can perform decryption of encrypted information & no aid of computers needed. In visual cryptography a secret image is transformed into several share images. These share images are meaningful but noisy or distorted images. Combination of these share images can reveal the original secret image. This paper reviews two methods for visual cryptography of color images based on Shamir encryption method variants of k-out-of-n i.e.2-out-of-2, 2-out-of-n, n-out-of-n, and k-out-ofn scheme encryption method.

Visual Cryptography is a special encryption technique to hide information in image in such a way that it can be decrypted by the human vision if the correct key image is used. Visual Cryptography uses two transparent images one image contains random pixels and the other image contains the secret information. It is impossible to retrieve the secret information from one of the image. Both transparent images and layers are required to reveal the information. The beauty of the Visual secret sharing scheme is its decryption process i.e. to decrypt the secret using Human Visual System (HVS) without any computation

International Journal of Computer Applications, 2014

Secret message in the form of image can be concealed into two or more images in Visual Cryptography (VC) schemes. The secret image can be recovered simply by stacking the shares together without any complex computation involved. The shares do not reveal any information about the secret image if they are viewed separately. In this paper, a color visual cryptography scheme using a combination of Meaningful Shares (MS) and a Key Share (KS) is proposed. These MS will not provoke the attention of hackers. The proposed scheme makes use of the XOR operation to create KS from the MS and secret image. The secret image can be decrypted by stacking the n-1 meaningful shares and key shares together by performing XOR operation. Experimental results show that the new scheme is perfectly applicable and achieves a high two level security.

2013

Visual Cryptography is a special type of encryption technique to obscure image-based secret information which can be decrypted by Human Visual System (HVS).A digital envelope is data container that is used to protect a message through encryption and data authentication. A digital envelope allows users to encrypt data with the speed of secret key encryption and the convenience and security of public key encryption. At first this cryptographic system divide the secret image by partitioning it into n number of split images.In this current work we have proposed a variable lengthSymmetric Key based Visual Cryptographic Scheme for colorimages where a Secret key is used to encrypt the every images and the Encrypted images are again encrypted by the fingerprints images. Finally every encrypted images are enveloped in other images using invisible digital watermarking.

Advanced Computer Control, 2009. ICACC' …, 2009

Visual Cryptography is a new cryptographic technique which allows visual information (pictures, text, etc.) to be encrypted in such a way that the decryption can be performed by human, without any decryption algorithm. Here we propose a Data hiding in halftone ...

2017

2018

Visual cryptography, a popular and simple technique uses the characteristics of human vision to decrypt encrypted images. It requires no computation for decryption from the user end. This paper emphasizes on basic cryptographic scheme proposed by Naor and Shamir with changed shares. Here, we focus on different shares with different combination of CMY color scheme to check whether proper encryption has taken place. Different combinations of shares were employed and the contrast reduction for decrypted images was 50% for some of the combinations which were also achieved earlier. Most of these studies, however, concentrated on binary images but very few on grayscale and color images. In this paper, a technique is presented to apply the visual cryptography scheme on colored images.

Due to the rapid advancement of the internet large amount of data is transmitted over the internet. Some of the transmitted information is very important like password, confidential file, security codes etc. so it is very important to provide security to these data. In computer technology there are two ways to provide security to the data they are cryptography & steganography. Although, in the past, there has been various research related to cryptography & steganography but neither of them provide enough & strong security. So this paper proposes a novel approach for data hiding by combining steganography & extended visual cryptography. Visual cryptography was invented by Moni Naor & Adi Shamir in 1994. Visual cryptography hide secret image within one or more images & then generate shares. For share generation this paper uses Visual Information Pixel (VIP) & error diffusion technique.

Cryptography is study of transforming information in order to make it secure from unintended recipients or use. Visual Cryptography Scheme (VCS) is a cryptography method that encrypts visual information (picture, printed text, handwritten notes) such that decryption can be performed using human visual system. The idea is to convert this visual information into an image and encypher this image into n different shares (known as sheets). The deciphering only requires selecting some shares out of n shares. The intent of this review paper is to contribute the readers an overview of the basic visual cryptography scheme constructions as well as continued work in the area. In inclusion, we also review some applications that take advantage of such secure system.

International Journal of Science and Research (IJSR)

Secret sharing is a method for distributing a secret among a group of participants. Visual Cryptography is a form of Visual Secret Sharing proposed by Moni Naor and Adi Shamir. Visual Cryptography Schemes hide the secret image into two or more images which are called shares. The secret image can be recovered simply by stacking the shares together without any complex computation involved. Color Visual Cryptography encrypts a color secret message into color halftone image shares. In this paper the various Visual Cryptography schemes are discussed and try to summarize the recent developments in Color Visual Cryptography technology.

2018

The visual cryptography is a type of cryptography that allows digital images to be divided into multiple numbers of printable shares called transparent shares. The images are transmitted after applying the visual cryptographic technique. The hacker cannot understand the distorted image and thus the data communication become secured. It exploits the human visual system to read the secret message from some overlapped shares. This technique overcomes the disadvantage of complex computations required in traditional cryptography. Visual cryptography can also be applied to color images by converting them into black and white binary images. In this research work, visual cryptographic technique is proposed and encryption and decryption are done using Blowfish algorithm. The proposed technique is implemented with Matlab coding. Keywords— Visual Cryptography, XOR, 16 standard RGB Color Image, Blowfish Algorithm, Encryption, Decryption.

Visual Cryptography is a special encryption technique which is used to hide information in images in such a way that it can be decrypted by the human vision only if the correct key image is used. While visual cryptography was developed for application to binary images, and is inherently based on binary logical operations, it can be applied to grayscale images through their halftone representations. In this paper, a new method for processing halftone images is proposed that improves the quality of recovered secret images. The approach described in the paper mitigates the two traditional problems in visual cryptography of pixel expansion and loss of contrast.

IRJET, 2021

Visual cryptography is a secret sharing technique for securing visual contexts like images or texts by encoding into multiple number of shares. In decryption process, one can decrypt the secret image (SI) by stacking the shares without any additional computations. Color visual cryptography (CVC) encodes a color secret image (SI) into several shares in which each color pixels are separately handled using RGB or CMY models. In this paper we proposed CVC technique for secret color images encoding schemes with multiple encryption algorithm to make the secret image highly secured. In this method, a color secret image is encrypted by extracting R, G, B component from the original secret image and halves of each of them into two separate matrices. Each of these matrices are then XORed with a randomly generated key matrices (Ki) to generate six different shares for each of the three color planes. By using Hou's scheme, share 1 and share 2 are then constructed by stacking the three first level shares and three second level shares of each color components respectively. The generated two shares are further encrypted by hybrid security algorithm called AES and Blowfish. On the recipient side, color SI is retrieved form these shares with the equivalent quality as that of original image by performing all the operations that we accomplished in the encryption processes in reverse order. The proposed method is then evaluated by using performance measures such as PSNR and SSIM. The result obtained by these two evaluation parameters show that the reconstructed image retain the quality of the original image. Therefore the proposed method is excellent for hiding secrets in the form color images confidently compared to the existing VCS schemes.

Visual cryptography was presented as a procedure permitting the visual data to be encrypted such that the decryption can be completed by human visual framework, without the guide of PCs visual cryptography discover applications in different divisions, for instance, E-voting for giving encrypted receipts. The traditional visual cryptography plans utilize pixel extension. In pixel development, each offer is m times the span of the secret image. In this manner, it can prompt the trouble in conveying these offers and utilization of more storage space. Visual cryptography is the scheme utilized for the discharge offer of image in that secret share the first picture is isolated into number of offers and that offer is appropriated to same number of members as each to one. That secret image is recoverable just when member share their secret. Security has turned into an indivisible issue not just in the fields entirely identified with secure communications but fields that have anything to do with storage of data as well.