Visual cryptography

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

New visual cryptographic schemes derived from orthogonal and mixed orthogonal arrays

Abstract: A visual cryptography scheme is a method to encode a secret image into shadow images called shares (transparencies) in such a way that certain qualifier subsets of shares enable the “visual” recovery of the secret image. The secret image appears only when all transparencies, of any of the qualifier subsets of shares, are superimposed. In this paper we propose new methods to generate such cryptographical schemes with interesting properties using orthogonal and mixed orthogonal arrays.

Mutual authentication using image processing and visual cryptography protocol for patient database

Abstract: Online Patient database is a particular type of service rendered by a chain of intercommunicated hospitals. Medical practitioners and clients are able to access their records or look into status of their diagnosis from any of the other or branch hospitals. The principle concern in online patient database is the authenticity of both the doctor and the client. Due to ineluctable intruding of the database on the Internet, it is very hard to rely on any kind of data on the Internet. The propounded approach of ours, based on Image processing technique and Visual Cryptography, the authentication problem is resolved. This particular paper proffers a technique of processing the Endoscopic Ulcer images based on Grow-cut and then divides it into Secret shares based on Random Grid Visual cryptographic Techniques. The total number of shares to be created depends on the strategy selected by the medical practitioner. If two shares are prepared, one of the shares is reposited in the Global Hospital Server, and the other is retained by the client. The client has to produce his/her secret share during the consultation. Client's share is then stacked with the Hospital Server share to obtain the original Endoscopic image. This method of correlation aids in concluding the decision based on espousal or denial of the output and hence confirms the client.

Secure masks for visual cryptography

Abstract: Visual cryptography provides a very powerful technique by which one secret can be distributed into two or more pieces known as shares. When the shares are printed on transparencies and then superimposed exactly together, the original secret can be recovered without computer participation. In this paper, we take multiple secrets into consideration and generate a key share for all the secrets; correspondingly, we share each secret using this key share. The secrets are recovered when the key is superimposed on the combined share in different locations using the proposed scheme. Also discussed and illustrated within this paper is how to embed a share of visual cryptography into halftone and colour images. The remaining share is used as a key share in order to perform the decryption. It is also worth noting that no information regarding the secrets is leaked in any of our proposed schemes. We provide the corresponding results in this paper.

Personalized Shares in Visual Cryptography

Abstract: This article deals with visual cryptography. It consists of hiding a message in two key images (also called shares). The decryption of the message is obtained through human vision by superposition of the shares. In existing methods, the surface of key images is not visually pleasant and is not exploited for communicating textual or pictorial information. Presently, we propose a pictogram-based visual cryptography technique, which generates shares textured with customizable and aesthetic rendering. Moreover, robustness characteristics of this technique to the automated decoding of the secret message are presented. Experimental results show concrete personalized shares and their applicative potentials for security and creative domains.

Multi-owner Architecture System Using Visual Cryptography and Watermarking for Secure Ownership in Cloud Environment

Abstract: Cloud computing is the best way for storing and computing data over an internet. Data can be shared in the form of texts, images, audio, and video. Sharing data securely over internet is a key issue. Cloud computing faces serious issues like security, integrity, and confidentiality of data. The most popular existing techniques for achieving data security faced conflicts like generation of large keys, the heavy computation of large keys, and collision attack of malicious users and also it meant for single owner. To overcome the limitations of existing techniques, we proposed a scheme and implemented image encryption and decryption using symmetric key. In the proposed system, we aim to improve security which implement three algorithms namely, visual cryptography (VC), AES (Advanced Encryption Standards), and watermarking. In this paper, the secret image is divided into multiple shares according to the number of users by visual cryptography, later AES is used. For more authentication and copyright protection, watermarking is used. In the obtained result, security is improved and also a key size is decreased which leads to data sharing among multiple authenticated owners securely without any conflict and original image is regenerated by combining all the shares.