A New Robust Image Cryptography Technique using Fractal Theory

In this paper an attempt has been made to design a cryptography scheme based on fractal theory. The visual cryptography scheme was implemented in such way that the secrete image will be encoded into a form where intruder finds at most difficulty to trace out the secrete image. In this technique the original or the secrete image has been divided into a number of sub images called share images. The share images are formed by taking a dummy image called host image and inserting the share or part of the secrete image. At the other end of the communication, from these share images, the shares will be separated and will be merged to form the original image. With this technique to transmit an image twice the memory of the secrete image size is required. By incorporating subjective tests the results are proved to better than the existing spatial domain techniques. The proposed technique can be extended by implementing using robust transforms. The objective test metrics need to be designed so that the evaluation can be done effectively.