Authenticated color extended visual cryptography with perfect reconstruction

摘要

Visual Cryptography Scheme (VCS) is an image safeguarding scheme which encrypts the secret text based image into multiple binary images called shares, which are then transmitted to participants. These shares are then stacked over by the participants to decrypt the secret image, however with reduced quality. In Extended Visual Cryptography Scheme (EVCS), these binary shares are encoded with cover images to generate meaningful shares. In order to enhance the decoded EVCS secret image quality, Two in One Image Secret Sharing Scheme (TiOISSS) was implemented, which offers perfect retrieval of the secret image. In this proposed scheme, the TiOISSS implemented for the color secret image with meaningful color shares with perfect reconstruction is proposed. This scheme uses Adaptive Halftoning technique to improve the EVCS image quality. Further, a color authenticated image and a text message are encoded in meaningful color shares to suppress any fake shares from the intruders, thus improving the security of the proposed scheme. Experimental results depict that the improvement in quality and security of the scheme.