A Review on Various Visual Cryptography Schemes

Cryptography is study of transforming information in order to make it secure from unintended recipients or use. Visual Cryptography Scheme (VCS) is a cryptography method that encrypts visual information (picture, printed text, handwritten notes) such that decryption can be performed using human visual system. The idea is to convert this visual information into an image and encypher this image into n different shares (known as sheets). The deciphering only requires selecting some shares out of n shares. The intent of this review paper is to contribute the readers an overview of the basic visual cryptography scheme constructions as well as extended work in the area. In addition, we also review some applications that take advantage of such secure system.