Based On The Chaos Of Information Encryption Method

Chaos was first discovered by an America meteorologist Lorenz in 1963, and turned into a new science rapidly. Chaos science merged into the other sciences, and was used abroadly in various fields. It was considered to be one of the three greatest physics achievements in twenty century. Chaos is the pseudorandom behavior that appears in confirmed no-linear system, and the greatest characteristic of a chaotic system is that the evolvement of system is very sensitive to initial value, and the future behavior of system is unforeknown in long term. The characteristic of chaotic system is just the same as that of modern cryptology. The continuous broad spectrum and the characteristic like noise make it has the nature of concealment, so chaos has abroad apllication foreground in field of information security.We carry through a complete study of the application of chaos in field of information security in this paper, and improve on some encryption scheme.To select an appropriate no-linear system for generating chaotic signals and judge whether the signals used in encryption is chaotic signals, chaotic theory and parameters for judging chaos is researched in this paper, and the software for calculating Lyapunov Exponents of various chaotic systems is also realized.The randomness of a sequence is an important standard for deciding whether it's applicable in encryption. To mensurate the randomness of different chaotic sequences, and choose a proper chaotic sequence, a set of randomness tests described by NIST(National Institute of Standards and Technology) are used for the statistical analysis of binary chaotic sequence.Because chaotic signals are easy to generate and have good random property, the application of chaotic sequence in image encryption has good effect, but those image encryption scheme existed can't resist plain-text attack. The new image encryption scheme based on chaos propsed in this paper can resist plain-text attack, and improve on the security of encryption greatly.Secure communication scheme based on chaotic synchronization is an entirely new secure communication scheme. Pecora and Carroll propose secure communication scheme based on chaotic synchronization first in 1990. The scheme makes use of the good characteristic of chaotic signals, and has high security. Lots of papers improve on the scheme after it has been proposed. We simulate the secure communication scheme based on chaotic synchronization in this paper, and evaluate the simulation results of these schemes.