A Digital Image Encryption Algorithm Based on Four-dimensional Hyperchaotic System
Fang Zheng · Jisuanji gongcheng · 2013
There are some problems for digital image encryption algorithm of low dimensional chaotic system such as small key space and low safety.On the basis of three-dimensional Lorenz system,by adding a new variable w to construct a four-dimension differential equations and adding a nonlinear term campaign to increase the complexity of the system,this paper establishes a novel four-dimensional hyperchaotic system.And an image encryption algorithm based on this hyperchaotic system is proposed and implemented.The system’s hyperchaotic properties is verified by the Lyapunov exponents calculation and simulation result of the trajectory of the system.By analyzing the security performance of the algorithm,it finds that the algorithm is extremely sensitive to key,has good diffusivity,and it can resist all kinds of attacks effectively such as brute force attack and known-plaintext attack.