A novel approach for secret data transfer using image steganography and visual cryptography

Abstract

Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message. It is a form of security through obscurity. The word Steganography in the modern day usually refers to information or a file that has been concealed inside a digital Picture, Video or Audio file. Essentially, the information-hiding process in a steganographic system starts by identifying a cover medium's redundant bits. The embedding process creates a stego medium by replacing these redundant bits with data from the hidden message. In this paper a new type of cryptographic scheme is proposed, which can decode concealed images without any cryptographic computations. The scheme is perfectly secure and very easy to implement. This is extended into a visual variant of the k out of n secret sharing problem, in which a dealer provides a transparency to each one of the n users, any k of them can see the image by stacking their transparencies, but any k -- 1 of them gain no information about it.