An approach for visual cryptography scheme on color images

Abstract

Visual cryptography, a popular and simple technique uses the characteristics of human vision to decrypt encrypted images. It requires no computation for decryption from the user end. This paper emphasizes on basic cryptographic scheme proposed by Naor and Shamir with changed shares. Here, we focus on different shares with different combination of CMY color scheme to check whether proper encryption has taken place. Different combinations of shares were employed and the contrast reduction for decrypted images was 50% for some of the combinations which were also achieved earlier. Most of these studies, however, concentrated on binary images but very few on grayscale and color images. In this paper, a technique is presented to apply the visual cryptography scheme on colored images.