利用混沌理论,基于Hénon映射和Logistic映射设计了一个复合混沌系统,并证明了其具有更好的初值敏感性。对产生的混沌二值序列进行美国国家标准与技术研究所(National Institute of Standard and Technology,NIST)随机数测试,分析得出该序列具有较好的随机性,可用于加密。依此设计了一个语音加密算法,实现了语音信号的加/解密功能。仿真分析表明,该混沌语音加密算法具有较高的安全性,能产生足够的密钥空间,有较强的保密性能。
By use of chaos theory, a hybrid chaotic system with variable parameter is designed based on Logistic map and Henon map in this paper, and we proved that it has higher sensitivity to initial conditions. American National Institute of Standard and Technology (NIST) statistical tests show that the chaotic sequences have good pseudo-randomness. Thus, it has adequate cryptographic properties in terms of randomness quality. Based on this system, a novel encryption algorithm is proposed, and the encryption and decryption function of voice signal is implemented. The simulation results show that the encryption algorithm has characteristics of high security and enough key space, and demonstrates significant cryptographic quaiities at a good security level.