నైరూప్య

A reversible visual cryptography technique for color images using Galois field arithmetic

Rajesh Kumar N, Manikandan G, Bala Krishnan R, Raajan NR, Sairam N

Nowadays, the most important study to provide confidentiality is digital image encryption. More and more proposals have been committed to inquire about Visual Secret Sharing (VSS) techniques. Traditional scheme was mainly focused on binary images and later investigations were extended to grayscale and color images. Visual cryptography encodes the secret information into n shares and distribute among of group of participants. Qualified participants can reconstruct the original image by superimposing the collected share images. Regrettably, the previous schemes still have weakness during the construction of secret shares and reconstruction on secret image. In this paper we present a reversible visual cryptography technique for color images using Galois field theory. A secret image is split up into two sub images and shared by the cover image to construct the stego images. Additionally Galois field theory is applied to construct brother stego images for effective transmission. Individual stego and brother stego images reveal nothing. The Galois field inverse operation of exponential is employed to reveal the secret image and pair of pixels in the brother stego images reveals cover images.