An advanced Diffie-Hellman approach to image steganography

Abstract

Diffie-Hellman key exchange is one of the most popular key exchange algorithms used in cryptography. Steganography is the approach of hiding information in a medium. When that medium is an image it is called as image steganography. The most popular image steganography algorithm in use presently is the Least Significant bit Algorithm (LSB). However this algorithm has proved to be easy to crack and hence rather insecure. The proposed algorithm uses a variation of the Diffie-Hellman algorithm to determine the pixel positions of the image to embed the information in. Both the sender and receiver maintain private keys. Along with this a public key is shared between them. The sender sends a public key to the receiver and vice versa. This public key is nothing but the product of the private key with the public key. The shared secret key is then the public key received multiplied with the private key of each. Now this value obtained is considered to be the pixel to embed data in. So all pixels with multiples of this value are embedded first using LSB. If still some data persists, then the shared key is substracted by 1 and all multiples of this new value are then filled. The process is repeated till the entire information is hidden.