Research & Publication
Abstract:Visual Cryptography (VC) is an encryption technique to encrypt a secret image into transparent shares such that stacking an enough number of shares reveals the secret image without any complex computation. In the existing visual cryptographic scheme the dealer or sender takes a secret image and encodes into shares. After encoding this shares are sent to participants. The receiver collects the shares and stack to get decoded secret image. here no verification is done. During share reconstruction phase the dishonest participant or dealer may submit fake shares instead of genuine shares. As a result fake image will be revealed. So effortless cheating is possible. To attain cheating prevention in VC a steganographic scheme is used to embed a secret message in each of the shares in random location during share generation phase called stego share. The security is enhanced by embedding each of these stego shares in cover work using LSB technique. At the time of recovery LSB extraction technique is required to decode the shares from cover and a message extraction technique is required to retrieve the text from share, which prevent cheating and check the originality of the share. And then use visual cryptography to reveal the original visual information by stacking the shares. The proposed visual cryptography scheme provides cheating prevention ability as well as improved security.