Hardware Design of Image Encryption and Decryption Using CORDIC Based Chaotic Generator

Abstract

This work proposes a Red Green Blue (RGB) image encryption and decryption digital system which uses random number sequence generators as core and also provides its internal architectural layout. SC-CNN (State Controlled Cellular Neural Network) based chaotic system which stands optimal in generating multi-scroll chaotic generators is inculcated in this system. The hyperbolic tangent function used in state equations of the chaotic generator is implemented via CORDIC (Coordinate Rotational Digital Computer) algorithm, which is an efficient algorithm to compute various trigonometric and hyperbolic functions. The above techniques are combined together to give hardware credibility to the scheme described. The randomness and the level of encryption are analyzed and validated with the help of multiple test inputs and corresponding encrypted outputs. The complete encryption and decryption flows are simulated using Xilinx Vivado 2019.1 and realized on FPGA (Field programmable gate array), Zynq 7 board, as the chosen device.