Optical color image encryption based on Hartley transform and double random phase encoding system

This paper reports a new method to realize the color image encryption based on Hartley transform and double random phase encryption technique. In the proposed method a color image is decomposed in to its Red, Green and Blue components. Each color is encrypted independently using double random phase encoding system and Hartley transform. Here the random phase masks and the Hartley transforms are the encryption parameters. It is shown that the decrypted image matches with the input image only when the correct keys are used during the process of decryption. To check the robustness of the technique, mean square error (MSE) between the decrypted and original image has been calculated. The technique can be realized by optical means and hence is useful for optical networks and holographic data storage systems for information security.