ABSTRACT:
Recent research on image encryption schemes has focused on chaotic systems in order to meet the demand for real-time secure image transmission over the Internet. In this paper, we propose a new image encryption scheme based on Shimizu-Morioka chaotic system. The scheme consists of two stages: the confusion (mixing) stage and the diffusion stage. In the confusion stage, we utilized the rich chaotic properties of the Shimizu-Morioka chaotic system by solving the system N time’s steps using Euler’s method and scrambled the positions of the pixel values of the image using the randomness of the solutions obtained from the chaotic system. In the diffusion stage, we generate N (where N is the size of image per colour) random integer numbers that is non-periodic and performed MOD and bitXOR operations on the shuffled image using the random numbers to obtain encrypted (diffused) image. The proposed algorithm is tested on a standard RGB image that is of size 256x256 and is stored with TIFF file format. Performance analysis on the proposed scheme such as the statistical analysis and the sensitivity analysis show that the proposed encryption scheme is reliable and strong enough to withstand different attacks.
KEYWORDS:
Image Encryption, Chaos, Cryptosystem, Shimizu-Morioka System, Equilibrium Point.
