Data hiding in halftone images using mathematical morphology and conjugate ordered dithering

Abstract

Visual Cryptography (VC) is a cryptographic technique that allows visual information such as textual images, handwritten notes etc to be encrypted in such a way that the decryption can be performed using the human visual system i.e. eyes. Here we propose an algorithm for data hiding in halftone images. This algorithm uses a morphological operation and ordered dithering, and is a modified version of DHCOD[1].In this paper we focus on improving the security and robustness of shares in VC and generating more meaningful shares with respect to basic cryptographic scheme.