改进混沌方程及其在保密VoIP系统中的应用与实现

传统二维Henon混沌映射由于复杂度低、混沌区间小，在应用于加密算法时存在安全隐患。针对这一问题提出了一种改进型Henon映射，相较传统映射混沌区间提升了82.35%，复杂度提升了60.8%，更加适用于混沌保密通信系统的设计。在ARM平台上，基于改进型Henon映射设计实现了一种保密通信系统。其中，加密端由音频编解码芯片产生明文数字话音信号，主控芯片使用二值混沌序列对其进行流密码加密，并通过以太网芯片完成密文话音在IP网的传输，解密端在帧同步后通过逆过程实现话音回放。实现结果表明，在计算精度范围内系统对密钥敏感性强，加密前后话音信号统计相关特性低于0.3，保密效果较好。

Improved chaotic equation and its application and realization in a secure VoIP system

The traditional two-dimensional Henon map has security risks when it is applied to chaotic encryption algorithms because of its low complexity and small chaotic interval.To solve this problem,an improved Henon mapping is proposed.Compared with the traditional mapping,the chaotic interval of the improved mapping is increased by 82.35%,and the complexity is increased by 60.8%,which is more suitable for the design of chaotic secure communication systems.On the ARM platform,a secure communication system is designed based on the improved Henon mapping.At the encryption end,the audio decode chip generates plaintext digital voice signal,and the main control chip encrypts it with stream cipher using chaotic binary sequence,and transmits the encrypted voice in IP network through Ethernet chip.After the frame synchronization,the decryption end realizes the voice playback through the inverse process.The realization result shows that the system is sensitive to the key within the range of calculation accuracy,and the statistical correlation of voice signal before and after encryption is less than 0.3,so the security effect is good.