在现有变参级联混沌通信系统中,系统密钥出现短周期态会导致密钥泄漏。针对该问题,分析级联混沌系统中Lyapunov指数随级联子系统参量变化的分布情况以及实时加解密系统的安全性,指出即使各独立子系统的Lyapunov指数均为正,其级联系统的Lyapunov指数也可能为负,负Lyapunov指数将导致密钥泄漏。为此,设计一个短程相关性线程对系统密钥进行实时监测,防止短周期态的发生,从而较好解决密钥泄漏问题。 In the existing chaotic communication system with variable parameters, short-period system keys can lead to key leakage. To solve this problem, we analyze the distribution of Lyapunov exponents with the parameters of cascaded subsystems and the security of real-time encryption and decryption system. It is pointed out that even if the Lyapunov exponents of each independent subsystems are positive, the Lyapunov The index may also be negative, and the negative Lyapunov exponent will result in a key leak. Therefore, we design a short-range correlation thread to monitor the system key in real time to prevent the occurrence of short-cycle state, so as to solve the key leakage problem well.