超混沌迭代同步在数字语音保密通讯中的应用

提出超混沌迭代系统的主动－被动（ＡＰＤ）同步方法，研究了它对语音的加、解密性能，证明此系统可以应用于数字语音保密通讯，并建立了计算机模拟超混沌迭代系统同步的数字语音加密解密系统，实现了混沌语音保密通讯．此方法具有同步速度快，恢复语音精度高，难于破译的特点

THE APPLICATIONS OF HYPERCHAOS SYNCHRONIZATION TO DIGITAL SPEECH SECURE COMMUNICATION

Since Pecora and Carroll proposed chaos synchronization in 1990, the application of chaos to secure communications has become one of the hottest topics. Up to now, most of the researches have been concentrated on analog privacy systems using chaos dynamics. This may be a drawback in practice, for most of those communication schemes show an intrinsic weak robustness. At the same time, the reports on digital secure communication are rather few, but it can give some new ideas to the study. In this paper, we give a system of synchronizing chaotic signal by using two identical one-way coupled ring map lattices (OCRML) with active-passive decomposition (APD). We prove that the system can produce hyperchaos of more than two Lyapunov exponents and perform digital speech secure communication. The system, in which transmission signals are hyperchaos with high dimensions, is more robust and safer against external imitations and attacks than the low-dimensional chaos currently proposed for secure communication. We also introduce the computer simulation for speech privacy communication. It shows that the receiving and transmitting systems can be synchronized in a finite number of steps and the information can be recovered from the transmission signals with very high quality.