Major Developments in Visual Cryptography

Abstract

Visual cryptography is a cryptographic mechanism that gets applied in visual information protection for secured transfer of data. The encryption makes the decryption a mechanical operation.The secret image gets converted into several share images. The share images are distorted/ noisy images which will give the correct image only when placed in the right combination. This paper reviews various visual encryption and decryption mechanism with the safe transmission of information from the literature. This paper about visual cryptography discusses, general access structure, halftone, colour, progressive, region incrementing, extended visual cryptography, colour extended visual cryptography, XOR and OR visual cryptography and the applications of visual cryptography. The applications discussed here are banking security, steganography, crime records, intelligence communication, multilayered Id cards and fingerprint records. The paper provides an overview of advances in VCS where each technique overcomes the problem(s) faced in the other manner.