Visual cryptography

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

OR Operation Based Deterministic Extended Visual Cryptography Using Complementary Cover Images

Abstract: In visual cryptography, random shares are generated from a binary secret image whereas in extended visual cryptography, meaningful shares are generated using the scheme. There are lots of constructions in visual cryptography and extended visual cryptography for both general and special access structures. Here in this paper, we are proposing an extended visual cryptographic scheme with improved contrast and less pixel expansion for the special access structures (t, k, n) and \( \left( {\frac{n}{2} + 1,n} \right) \) where each participant hold single meaningful image as share. The cover images used for creating shares in the proposed schemes are complementary in nature.

Tracking-Tolerant Visual Cryptography

Abstract: We introduce a novel secure display system, which uses visual cryptography [4] with tolerance for tracking. Our system brings cryptographic privacy from text to virtual worlds [3]. Much like traditional encryption that uses a public key and a private key, our system uses two images that are both necessary for visual decryption of the data. The public image could be widely shared on a printed page, on a traditional display (desktop, tablet, or smartphone), or in a multi-participant virtual world, while the other private image can be exclusively on a user's personal AR or VR display. Only the recipient is able to visually decrypt the data by fusing both images. In contrast to prior art, our system is able to provide tracking tolerance, making it more practically usable in modern VR and AR systems. We model the probability of misalignment caused by head or body jitter as a Gaussian distribution. Our algorithm diffuses the second image using the normalized probabilities, thus enabling the visual cryptography to be tolerant of alignment errors due to tracking.

A Novel Visual Cryptography Scheme Shared with Edge Information Embedded QR Code

Abstract: QR code has been widely used in our daily life due to its convenience, and the security of QR code becomes a rising problem. In this paper, we introduce a new algorithm that adds the edge of the gray image to the QR code, and the edge information is captured by the Canny detector. And then we use the random grid based visual cryptography scheme (RG-VCS) to generate shares. Each share of the VCS is an individual QR code that can be scanned by a QR code reader, and the secret information can be decoded by purely stacking without computation. Meanwhile, we can also recover the secret image with better visual quality with the help of computation.

An Efficient and Secured Data Sharing Approach through Image Transmission

Abstract: The privacy of transmitting data in the era of super-fast internet and high-volume data generation has become a tough job. To solve this problem, the combination of steganography and visual cryptography together is considered. Steganography is the process of concealing some data inside any form of digital data. The proposed method takes the original image and the secret message is encoded in its LSB (least significant bits), where genetic algorithm modifies the pixel values of encrypted image, therefore making the secret of the message tough to crack and then secretly hides the data in the original image and it is detected after undergoing visual cryptography which helps to encrypt visual information so that on decryption, data or the information appears as an image. The aim of this model is to design an efficient and secured algorithm for better reliability, security and efficiency for a secret message.

Improved the Security Strength of Visual Cryptography using Feature based Watermarking Technique

Abstract: Data integrity and confidentiality is major issue in internet based communication. For the integrity and confidently used various cryptography and stenography technique. The traditional message hiding technique faced a problem of intruder. The intruder easily decrypts the image and gets information. For the improvement of security strength used various key cryptography technique for hiding of information. In consequence of data hiding visual cryptography is another milestone. The process of visual cryptography used technique of share generation for the authentication of image. The process of share generation used mathematical formula and derivations. In this paper proposed feature based watermarking technique for visual cryptography. The feature based process used two feature property of image, color and texture feature. The color feature property generates a key value and texture feature property generates the value of share for the visual cryptography. The proposed method is simulated in MATLAB software and applies some geometrical attack for the measuring of security strength. General Terms Visual Cryptography, Watermarking, Geometrical Attack Share Generation