Optical data security using Hartley transform, pixel scrambling and chaos theory for images

This paper reports an efficient optical image encryption and decryption technique using Hartley transform, chaos function and pixel scrambling. In this method, pixel scrambling, chaotic random phase mask generated by using logistic map and the Hartley transform are used to encrypt the original image. Chaos functions are highly sensitive to the initial condition thus higher security is achieved. It is shown that the decrypted image matches with the input image only when the correct keys are used during the process of decryption. MATLAB 7.0 is used for the simulation and demonstration of the proposed technique. Mean square error (MSE), histogram analysis and the correlation coefficient between the decrypted and the original image has also been calculated in the support of the proposal. The original and decrypted images are highly correlated if the correct encryption parameters are used during the process of decryption. The technique can be realized by optical means and hence is useful for optical networks.