Cellular automata + LFSR + synthetic image: A trio approach to image encryption

Image encryption plays a crucial role in modern day secure multimedia communication. Confusion and diffusion are the two important mechanisms to encrypt the images employed in most of the image encryption schemes. In this paper, a grayscale image encryption method has been proposed with the confluence of Linear Feedback Shift Register (LFSR), Cellular Automata (CA) and hardware generated synthetic image. CA manages scrambling as well as diffusion. LFSR generates diffused bits which are sampled with hardware created clock source on Cyclone II FPGA in order to generate synthetic image. Synthetic image obtained through this random sampling process on FPGA enhances the randomization of encrypted images which has been evaluated with parameters such as entropy, correlation, histogram, differential, encryption quality and error metric analyses. The encryption and decryption processes were implemented using LabVIEW 2013 platform.