Visual cryptography

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

Design and Implementation of a Novel Authentication Algorithm for Fool-Proof Lock-Key System Based On Visual Secret Sharing Scheme

Abstract: The paper aims at creating an authentication algorithm using visual cryptography that creates a fool-proof lock-key mechanism wherein a lock can be opened by its paired key only and the key cannot be duplicated. In our proposed mechanism we uses a lock and a key, both is one part of given secret image. Every lock-key pair has one associated unique image. The lock is just like a safe door which has a memory and that can be used to transmit and receive signals like the key. Another part of the mechanism is that the lock and the key can change the pixel distribution of the some parts of the secret image when unauthorized access is going on.

An improved secret sharing using XOR-based Visual Cryptography

Abstract: In order to share a secret information among a group of participants, the method of secret sharing is used. The secret sharing method that is used to share or encrypt images is called Visual Cryptography. The main problems that subsist in Visual Cryptography are pixel expansion and poor image quality. Research are being conducted to solve the above mentioned problems. In this research, effective technique of share generation based on XOR-based visual cryptography for General Access Structures is introduced. Perfect restoration of the secret, no pixel expansion and no code book requirement are the advantages that the algorithm is expected to have. The generated shares are then covered in an image using steganography which provides additional security.

Visual Cryptography Scheme for Gray Scale Images based on Intensity Division

Abstract: Broadly speaking a term Cryptography used to secure & hide the original information of a message from the unauthorised users. First time used to encrypt a plaintext into cipher text where a key was associated at the time of encryption to change original content into some other form i.e. decrypted message. And same key was used to decrypt that message into original form. In the modern communication era, people begin to transmit huge digital and multimedia information through the public network. During the transmission, most important thing is to secure data, for which a different kind of cryptography used, known as Visual Cryptography Scheme (VCS). This paper presents a new VCS approach & its implementation for gray scale images based on Intensity Division. In this approach the intensity of a pixel is divided into MSBs & LSBs. Two shares are generated using MSBs and at the receiver’s end stacking of these provide the revealed image. It also improves the quality of shared images even after decryption of the secret image. This is finally compared with the original Host image. Performance of this approach can be measured by calculating MSE & PSNR and Histogram.