Research On Generation,Analysis And Application Of Complicatied Hyper-Chaotic System

Chaos means inherent randomn motions which seem to be irregular that appear in a determinist system. Since Lorenz discovered the first chaotic attractor in1963, chaotic dynamics has been well developed in the last50years, achieving satisfactory results. It has been applied in fields such as optimization and encryption. Chaotic dynamics has many superiorities in encryption:the dispersibility and inherent randomness of chaotic orbits satisfy the basic principles of encryption; sensitivity to initial value of chaos helps improve the sensitivity of the key, which improves the security of the encryption system; Chaos is also a determinist system which guarantees the reliability of the encrytion and decrytion.The characteristic of hyper-chaos is that it has two or more Lyapunov exponents. The greater the plus Lyapunov exponents are, the more chaos is the system. The orbits separate in more directions, system behaviors more complicated. So hyper-chaos exhibits more application future than chaos.This paper obtains a hyper-chaotic attractor by introducing a state feedback controller to a continuous autonomous3-D chaotic system. The new system possesses two plus Lyapunov exponents, which implies that it is highly disordered and more complicated in dynamics. A four-wing structure can be seen from the phase portraits of the new hyper-chaotic system. Hyper-chaotic characteristic of the new system is verified from different views such as Lyapunov spectrum, Poincare sections and power spectrums. This new four-wing hyper-chaotic system possesses abundant dynamic characteristics. Local bifurcation of the new system is analysised. The center mainfold of the new four-wing hyper-chaotic system is caculated by using center mainfold theorem. The parameter conditions are researched when the new system undergo local bifurcation. The new four-wing hyper-chaotic system possesses abundant dynamic characteristic. It experiences different dynamic states:single orbit, periodic, quaci-periodic, chaotic and hyper-chaotic. The new system is easier for circuit implemention because of its simple construction. An analogous circuit is designed on the Multisim10.0platform by using simple components like multiplier and amplifier. PCB of the new four-wing hyper-chaotic system is constructed, and the phase portraits of the attractor are observed from the oscilloscope. Outcome of the circuit implementation fits the results of the circuit and numerical simulation, verifying the existence of the new four-wing hyper-chaotic attractor on the physical level.Due to the work above, A encryption algorithm based on the new four-wing hyper-chaotic system is Investigated. Pixel values are diffused by adding the Pseudo random sequence flow generated by the hyper-chaotic system to the pixels. A simulation program is designed to realize the encryption algorithm. Problems such as the sensitivity of the key, safety and reliability of the algorithm are discussed through the simulation of the encryption and decryption of a digital image.