An Approach Of Image Hiding And Encryption Based On A Chaotic System

Digital Image Information is an important part of Network Information,the security of digital images was more and more important nowadays with the big development of modern communication and computer network techniques.Because those characteristics of image such as large data,high redundancy and self-similarity which are different from other digital informations,so traditional encryption methods are no longer suitable for ensure the security of digital image informations.These years some special schemes for image encryption that based on chaos were proposed by some researchers,and these methods show good performance in practice. But there are also some problems just like the limited accuracy of chaotic sequences in the computer simulation and Complex chaotic sequences' chaotic characteristic and so on.All of this needs further studied.For all the things and problem we faced to,this paper introduce the histroy and development of the chaotic encryption and the encryption of digital image in the introduction chapter.After that,some basic theories and methods of encryption,chaos and security of digital images were introduced by this paper in the second chapter which include the conception and the sort of encryption,the character and determinant of chaotic system,the storage method of digital image file and so on.And also,the algorithm of Lyapunov exponent was introduced dearly.In order to get binary sequences,which are random and sensitive to the initial values,this paper presents an approach of generating chaotic sequences based on a new hyper chaotic system in the following chapter.After tested with rules which confirmed by the standard FIPS-140-2,the binary sequences was testified to have the properties of randomicity and sensitive to the initial values that can nicer apply in the domain of Cryptography and can be used in the improved image hidding method based on a new hyper chaotic system in the fourth chapter.This method including improved magic-cube scrambling and pixels permutation;and the further processing are used to hide the pre-encrypted image.The effect of hiding is also analyzed by using the method of accessing.Simulation results indicate that the method has good efficiency and security characteristic.