Cheating Prevention Schemes for Visual Cryptography

Abstract

Visual cryptography is an encryption technique to encrypt a secret image into different shares such that stacking a sufficient number of shares reveals the secret image. Most of the previous research work on VC focuses on improving two parameters: pixel expansion and contrast. We considered the cheating problem in the visual cryptography scheme and investigate various cheating prevention schemes. During the reconstruction of the secret, one participant, called cheater, may release a false share. As a result a fake image will be revealed.