Image Encryption Based on Fractional Order Lorenz System and Wavelet Transform

Abstract

To securely transmit data in open networks, encryption must be used. In this paper, cryptography technique of images is presented with chaos and Discrete Wavelet Transform (DWT). Fractional order Lorenz system that provides an expanded in key space is used to encrypt image. All properties of randomness and nonlinearity which are owned by this chaotic system are guarantee a highly secure and robustness for Encryption process. As well as DWT offers additional space and security by using wavelet domain to shuffled image pixels after passing in DWT filters and sampling. The combination between Lorenz system and DWT have been taken to make the image more secure and thus make very hard to get back the original image without having its correct key and procedure which were used to encrypt. The results show a large sensitivity to a small change in the secret key or DWT family type. Therefore, high complicated image security is offered using this system.