A Novel Subliminal Channel Found in Visual Cryptography and Its Application to Image Hiding

Abstract

Visual cryptography techniques have been extensively investigated since the invention and extension to numerous applications such as image encryption, visual authentication, digital watermarking and image hiding. In this paper, a new subliminal channel found in visual cryptography (SCVC) is presented. This subliminal channel is a secure way to convey an extra secret message in the plain form of an ordinary visual cryptography mechanism. To show the superioritysuperiority of the new perspective, a SCVC-based application for image hiding is demonstrated as an example. In such a way, this discovery implies the possibility of enhancing hiding capacity to image hiding. It's worthwhile to note that the extra computational cost is extremely low upon increasing the extra hiding capacity.