Visual cryptography

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

A visual cryptographic scheme for owner authentication using embedded shares

Abstract: A new scheme for user authentication is proposed using visual cryptography and digital watermarking. The original image, mostly the photograph of the authorized person is split into shares. One of the shares is kept within the server and the other one will be printed on the identification card issued to the user. The personal information unique to the user along with his signature will be embedded within the printed share. Least significant bit watermark insertion algorithm has been used for embedding data. Experiments show that the method is efficient and effective. It was possible to retrieve the watermark information from the printed share read through a reading device with no distortion. The method can be implemented with minimum processing cost.

Region Incrementing Visual Cryptography Scheme with Decrypt Regions Perfectly Recovered

Abstract: In order to optimize the recovery quality of Region Incrementing Visual Cryptography Scheme (RIVCS), by adding identities for shares and combing the random numbers, an XOR-based single-secret sharing Visual Cryptography Scheme (XVCS) with individual participant holding multi-share is designed. On basis of this, the secret sharing and recovering algorithms for XOR-based RIVCS (XRIVCS) are designed. For the decrypt regions, XVCS is used to share, and for the not decrypt regions, the random numbers are filled to keep the secret. The experimental results show that, the proposed scheme can realize the perfect recovery of decrypt regions, and decrease the storage and transmission cost effectively.

A Robust Blind watermarking using Fractional Fourier Rework

Abstract: Watermarking is one of the great options in the field of digital data. In this paper we provide a method of robust invisible watermarking in which we are going to use method of Fractional Fourier Transform (FrFT) and Visual Cryptography (VC) in combine. Here in this method our aim is not to modify the original image by adding watermark into it, rather we are going to the use the sharing technique of Visual Cryptography know as Visual Secrete Sharing. In this technique of VSS, two shares namely Master Share and Ownership Share are generated. Feature extraction of original image is done by using Singular Value Decomposition, which are then used to generate master share. This master share combined with secrete image which is watermark are then used to generate ownership share using visual cryptography technique. Normally both shares are separate, and they individually do not provide any information but by stacking them one can get secrete image for ownership identification. We use FrFT in our scheme to make this application robust so the watermark can retrieved without the help of any other image.

A novel approach for (3, n)-threshold visual cryptography

Abstract: In this study, we propose a novel design for (3, n)-threshold visual cryptography by using the theory of the combinatorics to achieve an excellent contrast (visual effects) in the stacked image. Compared to the related works, this study has the following advantages: (1) the design concept is simple and easy to implement; (2) the stacked image’s contrast is optimal when we choose n–n+1 positions to fill 1 in the columns of the dispatching matrices that are needed in applying the theorem of visual cryptography and the restored image’s contrast is better than other researches in the field of (3, n)-threshold visual cryptography; (3) our method is suitable for any types of images; (4) the size of the transparencies are the same as the secret image.

Visual Cryptography Schemes for Secret Colour Images Sharing

Abstract: Visual cryptography is one of the techniques used to encrypt the colour images by dividing the original image into transparencies. The transparencies can be sent to the intended person, and at the other end the transparencies received person can decrypt the transparencies using our tool, thus gets the original image. Our proposed Visual cryptography provides the demonstration to the users to show how encryption and decryption can be done to the images. In this technology, the end user identifies an image, which is not the correct image. That is, while transmitting the image the sender will encrypt the image using our application here sender gets the two or more transparencies of the same image. Our application provides an option to the end user of encryption. The end user can divide the original image into number of different images. Using our application we can send encrypted images that are in the format of GIF and PNG. The encrypted transparencies can be saved in the machine and can be sent to the intended person by other means [source].