Chaos Synchronization Between Unified Chaotic Systems And Design Of Block Cryptographic Scheme

Chaos phenomenon is one of the most important science discovers and learning research hotspots, its application in secret communication is very potential. This paper integrates the method of theoretical deduction and numerical simulation to study the problem of chaos synchronization and cryptographic scheme designing of and get the following two productions:Firstly this paper researches the chaos synchronization problem of unified chaotic systems. Based on the theory of Lyaponuv stability criterion, the generalized synchronization, the synchronization based on observation, and coupled unified chaotic systems synchronization are studied. The synchronization conditions, methods, theoretical deductions and the constitution of responding systems are given. The numerical simulation shows the rapid synchronization of driven and responding systems with different initial value, the validity of these methods are proved further.Then a new cryptographic scheme is designed based on the study of current chaotic cryptosystems: Before the encryption, the plaintext and a good chaotic attractor are divided and their divisions are corresponded, the parameters and initial value can be the keys, the variable m links the plaintext and the chaotic system. In the progress of encryption, the initial value is iterated until in the appointed division. The result is dispersed then subtract the plaintext value, then model the division number as the ciphertext. The variable m changes in each iteration and each encrypting cycle, the change of each plaintext value can affect all remaining encryption. Decryption is the adverse process. The encryption and decryption of text files is realized and system cryptanalysis shows its good performance from the following aspects: the sensitive dependence on the keys, statistical performance and so on.