中文摘要：

以Lyapunov稳定性理论为基础，研究了一种三个耦合的恒等系统的全局同步的方法．通过选取适当的耦合参数，使得三个耦合的混沌系统达到同步．基于混沌遮掩的方法，把这种同步方案应用到保密通信．利用三个耦合的恒等系统，提出了一种二次加密方法，在前两个耦合的系统中加密后，利用后两个耦合系统再一次加密．通过加入随机白噪声干扰，对多级混沌保密通信系统进行噪声干扰分析和计算，并用小波分析理论对加噪信号进行处理．仿真结果表明，含有噪声的有用信号经小波理论处理后，可以很快无失真地恢复过来．

英文摘要：

Based on Lyapunov stabilization theorem, a global chaos synchronization scheme of three coupled identical systems is investigated. By choosing proper coupling parameters, the three coupled chaos systems realize synchronization. Then this method was applied to secure communication through chaotic masking, using three coupled identical systems, propose a novel method of chaos eneryption. After encrypting twice in two transmitters and a receiver, information signal can be recovered exactly at the receiver end. In consideration of the interfering of Gauss noise, the results of encoding and decoding are simulated and analyzed for the multistage chaos synchronized system. Analyzes the characteristics of noise and then presents a de-noising method which takes wavelet. The simulation results show that the noisy signal can recover the original image without any distortion with wavelet transformation is applied.