加密算法研究及其在数字对讲机上的实现

发布时间：2018-08-23 15:30

【摘要】：数字对讲机具有抗干扰能力强,通话质量好,频谱利用率高,灵活性高和易于集成等特点,是专用移动通信领域应用范围最广的移动终端。其主要应用于对指挥调度功能要求较高的部门和企业。对公安或者军队等语音安全通信要求较高的部门来说,为了防止语音信息在中间传输环节被窃听,研究数字对讲机中语音加密算法,使得语音以密文的形式传输,具有重大意义。本课题着眼于混沌加密技术,设计了一种数字对讲机语音加密方法。混沌是确定性系统的一种貌似无规则运动。混沌系统具有初值敏感性和随机性等优点,利用混沌系统可以设计快速且安全的加密算法。近年来混沌理论及其应用也受到了密码学界的广泛关注。本文的主要研究工作包括如下:1.本文首先介绍了数字对讲机语音加密的发展现状和趋势,阐述了混沌密码学和传统密码学的关系,分析了混沌密码学在数字对讲机语音加密中的可行性;进而研究了混沌密码学的相关理论,学习了混沌密码学的设计方法和理念。最后基于STM32硬件平台设计了数字对讲机语音加密系统。2.针对语音加密,本文首先设计了一种基于Hénon映射和Logistic映射的动态变参数复合混沌系统。从初值敏感性、相关性、李雅普诺夫指数和随机性几个方面深入分析了该复合混沌系统。分析结果表明该系统能产生随机性好的密钥序列,可用于语音加密。然后设计了混沌加密算法,并在MATLAB平台上实现了对语音的加密和解密操作。实验结果表明,该算法具有较足够的密钥空间和较快的加密速度,能满足语音加密要求。3.在此基础上,本文提出了一种数字对讲机实时语音加密方案。首先利用线性同余发生器及基于Chebyshev映射和Cubic映射的复合混沌系统设计了加密算法。然后提出了基于AMBE和CSP1027的声码器模块,主要实现了语音的采集和压缩编码,同时使得声码器模块的处理时延满足加密系统要求。最后在STM32开发平台实现了混沌语音加密算法,完成了语音加解密。经测试表明,该加密系统具有较高的安全性和较好的实时性。
[Abstract]:Digital interphone is the most widely used mobile terminal in the field of special mobile communication because of its strong anti-interference ability, good communication quality, high spectrum efficiency, high flexibility and easy integration. It is mainly applied to departments and enterprises with high requirements for command and scheduling functions. In order to prevent the voice information from being eavesdropped in the intermediate transmission link, the speech encryption algorithm in the digital interphone is studied to make the voice transmit in the form of ciphertext, in order to prevent the public security departments such as the public security or the military from eavesdropping in the intermediate transmission link. Of great significance. This paper focuses on chaotic encryption technology and designs a digital interphone voice encryption method. Chaos is a seemingly irregular motion of deterministic systems. Chaotic systems have the advantages of initial sensitivity and randomness, so a fast and secure encryption algorithm can be designed by using chaotic systems. In recent years, chaos theory and its application have been paid more and more attention in cryptography field. The main research work of this paper is as follows: 1. This paper first introduces the development and trend of digital interphone speech encryption, expounds the relationship between chaotic cryptography and traditional cryptography, and analyzes the feasibility of chaotic cryptography in digital interphone speech encryption. Then, the related theories of chaotic cryptography are studied, and the design methods and concepts of chaotic cryptography are studied. Finally, a digital interphone voice encryption system. 2. 2 is designed based on STM32 hardware platform. For speech encryption, this paper first designs a dynamic variable parameter composite chaotic system based on H 茅 non mapping and Logistic mapping. The complex chaotic system is analyzed in terms of initial value sensitivity, correlation, Lyapunov exponent and randomness. The analysis results show that the system can generate random key sequences and can be used in speech encryption. Then the chaotic encryption algorithm is designed, and the encryption and decryption of speech is implemented on MATLAB platform. Experimental results show that the algorithm has sufficient key space and fast encryption speed, and can meet the requirements of voice encryption. On this basis, this paper proposes a real-time speech encryption scheme for digital interphone. Firstly, the encryption algorithm is designed by using linear congruence generator and complex chaotic system based on Chebyshev map and Cubic map. Then a vocoder module based on AMBE and CSP1027 is proposed, which mainly realizes the speech acquisition and compression coding, and makes the processing delay of the vocoder module meet the requirements of the encryption system. Finally, the chaotic speech encryption algorithm is implemented on the STM32 platform, and the speech encryption and decryption are completed. The test shows that the encryption system has higher security and better real-time performance.
【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.54;TP309.7

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