Cheating Prevention in Improved Extended Progressive Visual Cryptography Scheme

Abstract

Securing information from unauthorized access is mandatory in day-to-day life. Secret sharing schemes deal with security of information while exchanging it with others. Visual cryptography scheme (VCS) is a secret sharing scheme for visual information like images and video. Right from the inception of VCS, various revisions are done to original VCS, like k out of n VCS, extended VCS, progressive visual cryptography scheme (PVCS), and so on. Some common issues of various VCSs are: pixel expansion, poor contrast of share images constructed, poor accuracy of reconstruction and management of noise-like random shares. Improved extended progressive visual cryptography scheme (IEPVCS) deals with all these issues, but suffers from the problem of cheating with VCS. The commonly used approach for cheating with VCS is to introduce fake shares in the system and affect the reconstruction of secret information. Very few VCS deal with cheating by fake shares introduction. A cheating prevention mechanism is introduced in IEPVCS to handle the issue of fake shares and prevent the recovery system from reconstructing wrong secret image.