Reach On Chaotic Synchronization And Its Application In Secure Communication

Chaotic phenomenon is a kind of random phenomenon, it appears in the deterministic nonlinear dynamic system, and it is one of the20th century greatest scientific discoveries. In the past few decades, as people unceasingly thoroughly had knowledge of chaos theory, more and more people began to study the subject of chaos synchronization, and their research results in the secret communication field achieved a wide range of applications. This thesis adopts the theoretical proof and numerical simulation two kinds of methods to study the chaotic synchronization problems and the application in secure communication. The main work is as follows:The synchronization of unified chaotic systems is studied. Using the linear feedback synchronization method we achieve the chaotic synchronization of the original Lu chaotic system, the effectiveness of the controller is proved in theory and through the numerical simulation results good synchronization process is obtained.The anti-synchronization of Lorenz hyper chaos systems is issued. In theory the design of chaotic controller can make two hyper chaos systems realize the anti-synchronization, and through the numerical simulation experiments we observe the good effect of the anti-synchronization. At the same time, we prove that if the control parameter’s value is bigger, the time to reach the anti-synchronization will be shorter.The problems of mixture synchronization of Lorenz hyper chaos system are studied. We theoretically prove that after adding controller, two hyper chaos systems can achieve of mixed synchronization of the coexistence of complete synchronization and anti-synchronization. Numerical simulation experiments further verify that the controller can effectively make two systems achieve mixed synchronization.We study based on state observer synchronization method. We choose the Chen hyper chaos system, first study the synchronization method based on state observer; using the theory analysis and numerical simulation method we verify the effectiveness of the synchronization. Then based on state observer synchronization a secure communication scheme is designed, and the scheme is feasible, which is validated through theoretical proof and numerical simulation.The application of chaotic synchronization in the encrypted information is studied. First the P-C synchronization method is used to let drive Lorenz system and response Lorenz system achieve synchronization, after synchronization, we use the key which is produced by synchronization to encrypt a random text information formed of A to Z26letters.By using the chaotic synchronization of the encryption scheme, we achieve the confidential transmission of the text information.