Stealth steganography in visual cryptography for half tone images

A novel approach for detection of cheating in visual cryptography based on steganography for hiding digital signature of the secret image is proposed. The proposed technique hides the verification bits of the signature in the different shares of the participants. For hiding binary ‘0’, no flipping of the subpixel is done in the block of the share, but change is done for hiding binary ‘1’ by flipping a white (black) subpixel in one of the blocks of black (white) share The hidden signature can be recovered in the presence of all shares and verified by comparing with the reconstructed digital signature in case of doubt.