Image Encryption Algorithm Based on a New Five-Dimensional Lorenz System

Abstract

AbstractFor the question of key space of image encryption algorithm based on the low dimension chaotic system is small and the safety is not high. On the basis of four-dimensional hyperchaotic Lorenz system, by adding the dimension of differential equations and adding a nonlinear term, this paper establishes a new five-dimensional hyperchaotic Lorenz system. And a digital image encryption algorithm based on this hyperchaotic system is proposed. First, we prove that the system is a hyperchaotic system, through the Lyapunov exponents calculation and simulation result of the trajectory and Chaotic attractor phase diagram. Then, a digital image encryption algorithm based on this hyperchaotic system is implemented. By analyzing the security performance of the algorithm, we found the algorithm is extremely sensitive to key, with very good diffusivity, and it can resist all kinds of attacks effectively such as brute force attack, chosen-plaintext attack and known-plaintext attack.KeywordsChaoticChaotic cryptographyHyperchaotic systemImage encryptionLyapunov exponents