Cyber Times International Journal of Technology & Management

Visual Cryptography is a variant of (k, n) Shamir’s secret sharing scheme in which a secret image is divided into n shares for each of the n participants and any k of them can see the  secret image by stacking their shares, but any k-1 can gain no information about it. (k, n) secret sharing scheme is vulnerable to cheating by dishonest or malicious Co-participants. Co-cheating prevention scheme can prevent cheating for more than one cheater. Many cocheating prevention schemes for single cheater have been presented in the past. These schemes are vulnerable when the no of cheater increases. In this paper, a co-cheating prevention scheme based on steganography is proposed which prevents cheating, where many cheaters present. The advantage of the proposed co-cheating prevention scheme is that it does not require any trusted third party. During the generation of shares a secret message is embedded in each of the share at random location. The embedded message can authenticate the shares. The combiner can extract embedded message before stacking their shares and verify the authenticity of shares.