Steganography Using Stochastic Diffusion for the Covert Communication of Digital Images.

This paper is devoted to the study of a method called Stochastic Diffusion for encrypting digital images and embedding the information in another host image or image set. We introduce the theoretical background to the method and the mathematical models upon which it is based. This includes a comprehensive study of the diffusion equation and its properties leading to a convolution model for encrypting data with a stochastic field that is fundamental to the approach considered. Two methods of implementing the approach are then considered. The first method introduces a lossy algorithm for hiding an image in a single host image which is based on the binarization of the encrypted data. The second method considers a similar approach which uses three host images to produce a near perfect reconstruction from the decrypt. In both cases, details of the algorithms developed are provide and examples given. The methods considered have applications for covert cryptography and the authentication and self-authentication of documents and full colour images.