基于混沌理论的遥测信息安全技术研究

【作者】 罗启彬；

【导师】 张健；

【作者基本信息】 中国工程物理研究院 ， 无线电物理， 2009， 博士

【摘要】 随着信息技术和通信对抗技术的飞速发展,信息在传输过程中的安全问题就日显突出,特别是对事关重要信息的再入遥测数据,采取何种技术来保证这些数据在开放空间中安全地传输到目的地,并尽可能使非授权方即便截获到这些数据也不能理解其真正含义,这是非常有意义的研究课题。近年来,随着混沌理论研究的逐步深入以及在应用领域所取得的重大进展,混沌密码学等技术逐渐成为当前研究的热点。可无论从安全性还是效率而言,现有的基于混沌理论的信息安全研究方案都还存在许多不足。本文主要进行基于数字化混沌理论的遥测PCM数据加、解密和基于遥测PCM数据的混沌脉冲调制技术研究。研究成果具体体现在：1.首先采用分组加密算法(如DES)和流加密算法对遥测PCM数据流分别进行加密,并通过比较收发两端的误码率情况,从而确定了流加密方式是适合遥测数据加密的加密体制,这样可避免接收误码的扩散。2.建立了产生混沌序列密码的新型数学模型-HYBRID映射,重点分析了该映射的混沌特性,包括混沌态的产生机制、相轨迹、需要等待的过渡过程长短等,并采用定时微扰混沌迭代初值的办法成功地解决了有限精度效应对混沌映射的影响,最后提出了具体的HYBRID伪随机序列的生成算法,仿真结果表明该算法所产生的密钥流序列能很好的通过标准的随机性能测试,同时具有良好的自相关和互相关特性等特点；接着利用DSP技术实现了该混沌密钥流。该方案具有数字化、结构简单、实现容易和速度快等优点,实验结果表明用该方法产生的混沌密钥序列具有较理想的白噪声统计特性,能适用于遥测数据的加密系统。3.建立了遥测PCM数据混沌加、解密系统的仿真平台,并结合收发两端密钥同步的实际情况,提出了“类一次一密”的遥测PCM数据混沌加、解密方案,并分析了收发两端密钥同步的具体措施,同时对该方案中密钥同步的可靠性、鲁棒性和安全性进行了分析。最后在多径瑞利衰落环境下对该系统进行了仿真验证。结果表明该方案不但没有引起收端的误码扩散,而且能够满足遥测PCM系统的加密强度要求。4.对遥测PCM混沌加、解密系统进行了实验验证。并根据工程实际情况,对发端的PCM数据流混沌加密方案进行了详细地分析设计,最后利用信道衰落仿真器模拟遥测信道的环境,实现了接收终端的解密处理,为遥测PCM加、解密系统的最终实施做了卓有成效的探索。5.分析了混沌脉冲位置调制与解调的原理,并对遥测系统中基于PCM数据的脉冲信号的保密传输技术进行了仿真分析,为遥测系统中的脉冲信号加、解密提供了一条新的思路。6.讨论了混沌理论在扩频通信领域中的应用,并在构建的混合映射的基础上,重点讨论了混沌扩频序列的产生及优选方案、扩频序列的性能分析等等,可供遥测多目标系统参考。在文章最后,我们对全文的研究工作进行了总结,并对基于数字化混沌理论的遥测领域今后要做的研究工作进行了展望。本课题的研究得到了中国工程物理研究院科学技术基金面上课题“混沌理论及其在遥测数据加密中的应用研究(20050429)”和NSAF联合基金课题“遥测数据编码及加密技术研究(10776016)”的资助。更多还原

【Abstract】 Under the rapid development of information technology, the security of information has attracted more and more attentions in recent years. Especially for the important information of the Reentry Telemetry system, what technology is adopted to ensure these data information transmitted safely to the destination during the data is transmitted in open space, and how to make the non-authorization side can’t understand the true meanings even if they can intercept these signal. This is a very important question. In these years, along with the development of the theory and application of chaos, many researchers are now focusing on the chaotic cryptography and information hiding based on chaotic theory. Nevertheless, considering the security and efficiency, there also exist some deficiencies in the presented information security schemes.In this thesis, we study mainly the information security based on the discrete chaotic systems, including the Reentry Telemetry PCM data and the pulse signal. Finally we establish the simulation platform of the PCM data encryption and decryption base on chaotic theory. As well as the information secure transmitting of the pulse signal in the Reentry Telemetry system is also investigated, for example the Chaotic Pulse Position Modulation technology.The main work and research results of this thesis lie in the following:1. Stream cipher mode will be ensured to encrypt the Reenter Telemetry PCM data, by comparison quantificational the block cipher (for example:DES) the stream ciphers. The error diffusion can be avoided in receiver if the PCM data is encrypted by stream cipher.2. A newly chaotic mathematics model has been put forward. That is HYBRID mapping. The characteristic of the HYBRID mapping is analysized, especially the phase trajectories near critical points, the stability of HYBRID system, and the timing perturbation approach is applied remedying the finite precision. The standard statistical tests demonstrate that the generated key stream has a random-like behavior,δ-like auto-correlation function and near-zero cross-correlation function. Next, the chaotic key stream is realized by using the Digital Signal Procession (DSP). The results shows that the chaotic key stream has excellent the statistic properties, and can be easily realized. It can be fit for encrypting PCM data.3. Based on chaotic theory, a simulation platform of the PCM data encrypted/decrypted in Reenter Telemetry is built. In this system, the synchronous scheme of the working key in both transmitter and receiver sides is designed. This method provides a realizable way for "one-time pad" in some sense. So we have solved successfully the reliability and the robust of the working key in receiver, and analyzed the security of the cipher system. At last this system is tested under the multi-path Rayleigh fading environment. MATLAB simulation shows the diffusion of error bit isn’t arise. Of course, the encryption intensity of the Reentry Telemetry PCM secret system is assured. In a word, some helpful reference can be provided for the realization of the Reentry Telemetry PCM secret system.4. The system experiment of PCM signal based on chaotic encryption/decryption has been validated. Especially aiming at the unique demand of the high-speed flying object, we have designed a scheme of chaotic encryption. By use of the Channel Fading Simulator, We have realized the chaotic decryption in receiver. In conclusion, some fruitful explore have been obtained by the experiment.5. The theory of Chaotic Pulse Position Modulation and Demodulation is researched. On the basis of the theory, we have discussed and simulated the information secure transmitting technology of the pulse signal in Reenter Telemetry system. A new thought about the pulse signal encryption/decryption in Reenter Telemetry system can be provided from the theory.6. The application of chaotic theory is discussed in spread spectrum communication fields. On the basis of a sort of newly chaotic mapping, we describe detailly the generating approachs of chaotic spreading sequence. Some criteria on optimizing spreading sequences and the method of choosing are also presented. By numerical simulation, the correlation and balance property of the chaotic spreading sequences are analyzed. Calculation shows that the pseudo-random character and the linear complexity are excellent to Logistic mapping, and these optimized chaotic spreading sequences are much better than Gold sequences. The results of this work are also useful reference to the Telemetry multi-objection system.Finally, the research work of this paper is summarized, and the future developing direction based on chaotic theory in Reenter Telemetry field is indicated.The dissertation was supported by the Science and Technology Fund of the China Academy of Engineering Physics{Subject Number:20050429), and the National safe Academic Foundation (NSAF, Grant No.10776016).更多还原