Visual cryptography

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

On the Security and Usability of Segment-based Visual Cryptographic Authentication Protocols

Abstract: Visual cryptography has been applied to design human computable authentication protocols. In such a protocol, the user and the server share a secret key in the form of an image printed on a transparent medium, which the user superimposes on server-generated image challenges, and visually decodes a response code from the image. An example of such protocols is PassWindow, an award-winning commercial product. We study the security and usability of segment-based visual cryptographic authentication protocols (SVAPs), which include PassWindow as a special case. In SVAP, the images consist of segments and are thus structured. Our overall findings are negative. We introduce two attacks that together are able to break all SVAPs we considered in the paper. Furthermore, our attacks exploit fundamental weaknesses of SVAPs that appear difficult to fix. We have also evaluated the usability of different SVAPs, and found that the protocol that offers the best security has the poorest usability.

Two Factor Authentication using Twofish Encryption and Visual Cryptography Algorithms for Secure Data Communication

Abstract: Dependence of the individuals on the Internet for performing the several actions require secure data communication. Thus, the reliable data communication improves the confidentiality. As, enhanced security leads to reliable and faster communication. To improve the reliability and confidentiality, there is dire need of fully secured authentication method. There are several methods of password protections were introduced to protect the confidentiality and reliability. Most of the existing methods are based on alphanumeric approaches, but few methods provide the dual authentication process. In this paper, we introduce improved graphical password authentication using Twofish Encryption and Visual Cryptography (TEVC) method. Our proposed TEVC is unpredictably organized as predicting the correct graphical password and arranging its particles in the proper order is harder as compared to traditional alphanumeric password system. TEVC is tested by using JAVA platform. Based on the testing results, we confirm that proposed TEVC provides secure authentication. TEVC encryption algorithm detected as more prudent and possessing lower time complexity as compared to other known existing algorithms message code confirmation and fingerprint scan with password.

Protecting medical images in cloud using visual cryptography scheme

Abstract: Healthcare providers generate large amounts of medical imaging data to meet the increased demand These digital records need to be processed and stored So, mass storage systems and powerful image processing software are required Nevertheless, to invest in a sophisticated local data center leads to high operating expenses To overcome this challenge, cloud computing has recently been adopted in healthcare sector In fact, this new paradigm offers scalable computational resources to the client as a service Furthermore, consumers are commonly charged only for cloud services utilization In spite of its demonstrated advantages, moving medical data to cloud computing brings security threats That is why we propose a method based on visual cryptography to secure medical image storage over cloud Indeed, this technique ensures privacy without complex mathematical computations The experimental results show that the proposed method ensures data confidentiality by splitting medical image into several shares Moreover, we propose a multi-cloud environment to reduce security risks and to improve performance

Secure mask for color image hidding

Abstract: Hiding image in a color image is a very interesting research topic, especially using very popular software such as Microsoft Windows Paint, Internet Explorer browser (IE) Mozilla Firefox, etc can achieve very amazing result. In this paper, we start from the select operation of IE, and introduce the mechanism how to hide a color image in a real natural image. Based on this, we generate an animation using this scheme. Using the select function of IE, we can toggle two completely different animations. We improve the hiding scheme and introduce how to embed the shares of visual cryptography into a natural color image, another share of visual cryptography works as a public key like the select operation of IE. We also introduce how to hide a visual cryptography share into a halftone image. The results are very robust and can resist print and scan tempering.