Visual cryptography

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

Sequential Multiple LSB methods and real-time data hiding: variations for Visual Cryptography ciphers

Abstract: In this paper, a general model approach of real-time data hiding and watermarking for image, video and audio communications is proposed. The aim is the development of security robustness variations and data-rate (capacity) extensions of Steganography fast schemes for RT (real time) or NRT (near real time) image, video and audio media communication and data hiding, with no significant distortion of the medium. Additionally, this paper includes the proposal of specific case models such as Steganography of the total of Visual Cryptography schemes of black and white images. Influenced by our survey on Spatial Domain Steganography techniques such as Multiple LSB (Least Significant Bit) algorithm, Matrix Embedding and Parity Coding, a new potential method is introduced called in brief from now on SMLSB (Sequential Multiple LSB) method comparing other respective methods and algorithms researched, SMLSB is a different approach on real-time and non-real-time data hiding, which gives an advantage of robustness, while it provides various modes of the method depending on the requirements. Also the method can be used for the specific occasion of Visual Cryptography Ciphers’ Steganography.

Visual Secret Sharing Schemes for Multiple Secret Images Allowing the Rotation of Shares*This paper was presented in part at Symposium on Cryptography and Information Secrity and Symposium on Information Theory and Its Applications, 2005.

Abstract: In this paper, a method is proposed to construct a visual secret sharing (VSS) scheme for multiple secret images in which each share can be rotated with 180 degrees in decryption. The proposed VSS scheme can encrypt more number of secret images compared with the normal VSS schemes. Furthermore, the proposed technique can be applied to the VSS scheme that allows to turn over some shares in decryption. From the theoretical point of view, it is interesting to note that such VSS schemes cannot be obtained from so-called basis matrices straightforwardly.

Friendly Color Visual Secret Sharing by Random Grids

Abstract: The visual secret sharing (VSS) approach by random grids (RG-based VSS) has drawn people's attention "again" recently. Nevertheless, the current RG-based VSS approaches suffer from the problem of meaningless share images (cipher-grids) so that it is not user-friendly to manage noise-like share images. This paper presents a novel color RG-based VSS scheme aiming at providing the friendly color cipher-grids with all the advantages of traditional VSS schemes. To our best knowledge, this paper is the first effort to develop the friendly technique. The experimental results show that the scheme does work.

Randomness in Visual Cryptography

Abstract: A visual cryptography scheme for a set P of n participants is a method to encode a secret image into n shadow images called shares each of which is given to a distinct participant. Certain qualified subsets of participants can recover the secret image, whereas forbidden subsets of participants have no information on the secret image. The shares given to participants in X ⊆ P are xeroxed onto transparencies. If X is qualified then the participants in X can visually recover the secret image by stacking their transparencies without any cryptography knowledge and without performing any cryptographic computation. This is the first paper which analyzes the amount of randomness needed to visually share a secret image. It provides lower and upper bounds to the randomness of visual cryptography schemes. Our schemes represent a dramatic improvement on the randomness of all previously known schemes.