The Analysis Of Chaotic Stream Ciphers

With the development of computer technology and internet technology, information security has become a hot topic of current research,as the most basic method of information security, cryptograph also receives abroad attention. The main properties of Chaos theory are determinacy,sensitive dependence on initial conditions,unpredictable result for long,etc,it is a safe form of nonlinear dynamical systems, based on the above characteristics, there is a close link between natural chaos and cryptography. This study focused on the analysis of chaotic stream ciphers, and study its applications. The main work of this paper is as follows:1.Study on the basis of chaos theory, describe its definition and motion characteristics,Analytize Lyapunov exponent and chaotic attractors,moreover, the research status of chaotic stream ciphers has been summarized.2.The cipher were analyzed, its basic theory and linear feedback shift register structure were studied, from the information of entropy, correlation, key space construct, studied conquer attack of the cryptograph.3.Research the design and implementation of chaotic stream ciphers, Logistic map and its characteristics were analyzed,the chaotic sequences generated by Logistic map were studied, in order to solve problem of cycle estimation difficult in the practical application of chaotic stream ciphers, cycle estimation method of Logistic cryptography were researched .4.The application of chaotic stream cipherswere studied, the Logistic chaotic stream and the standard A5/1 encryption algorithm were combined to design innovative encryption system, the encryption were applied to the image, the method were discussed in detail, and conducted experiments verification.