In recent years many researchers used chaotic systems to image encryption. Some related work is explained below:
Tianetal(2010) presented a new autonomous four-dimension hyper chaotic system, where the basic dynamical behaviours are investigated. The system possess one equilibrium point and four Lyapunov exponents obtain as LE1= 1.6170, LE2 =0.1123, LE3= 0, LE4= -12.8245,where the Lyapunov dimension has fractional nature calculated as 3.1348.
Baojie Zhang and Hongxing Li (2013) proposed an autonomous non-linear four-dimension hyper chaotic system on basis of Lorenz system. The dynamical behaviour of system was investigated with equilibrium Lyapunov exponents and dissipation which demonstrate that the new system possesses rich dynamical behaviour. Lyapunov exponents obtains as LE1= 1.156884, LE2=0.720394, LE3= 0.026702 and LE4 = -44.999849.