基于混沌理论的VoIP网络流媒体隐密通信研究

发布时间：2018-03-25 03:25

本文选题：隐写术　切入点：混沌　出处：《中国地质大学》2017年博士论文

【摘要】：随着网络和信息技术的发展,全球信息化加速,国家政治经济等信息也逐步数字化,各个国家在能源、交通、金融、商业和军事等方面都依赖信息网络,更加容易遭受安全威胁,隐密通信研究在军事保护和国家安全方面具有重要意义。VoIP作为一种网络多媒体中的实时服务,它能通过互联网提供低成本、高可靠性和全球IP服务,已经成为许多商业的主要媒体流通信工具。随着VoIP的使用越来越广,VoIP语音流的通信量在网络数据通信量中的比例日益增加,同时VoIP的实时性避免了在线检测和线下分析的可能,而且它涉及到网络通信各个工作层的多种协议,越来越多的研究者人员开始将VoIP作为一种理想信息隐藏载体进行隐密通信的相关研究。然而这些研究工作没有考虑现实网络中各种不稳定因素,如丢包会导致语音包中嵌入的秘密信息的不完整性。而且,实现安全高效的VoIP隐密通信,需要考虑对实时性要求较高VoIP通话质量。针对这些问题,本文充分考虑网络的各种不稳定因素如丢包和时延问题,对VoIP网络流媒体的隐密通信研究所作贡献如下:(1)在建立VoIP通信连接阶段采用基于认证的密钥协商技术,即在VoIP信令阶段进行密钥交换,在不影响VoIP语音通信质量的同时解决密钥的分配问题,使接收端用户能顺利提取和恢复秘密信息。(2)大多数的隐写算法都是在理想的实验环境下设计实现的,没有考虑网络拥塞导致的丢包等因素对隐密通信的影响,一般都是对所有秘密信息进行整体加密预处理。但是网络中不可避免的丢包问题可能会导致部分密文丢失,而使已经接收到的密文解密无法正确恢复得到明文。为了解决以上问题,本文提出一种基于AES分组加密算法的VoIP隐写方法,采用加密与嵌入同步的机制,利用AES-128加密算法的特点,将秘密信息分块加密,不同语音包中的秘密信息分别加密,在接收端能及时将语音包中的秘密信息提取出来,并解密为可读的明文信息,使任何一个嵌入有秘密信息的语音包丢失,也不会影响其他语音包中秘密信息的解密。而且通过AES分组加密,在保证秘密信息的安全性同时,尽可能地减少加密所耗时间,秘密信息的加密和嵌入几乎同时进行,从而减少时延。实验中分别用男声和女声语音作为测试样本,并且采用高度精密的语音质量测量仪器DSLA II对语音样本进行测量,实验结果表明包含有秘密信息的隐藏语音与没有嵌入秘密信息的载体语音相比,信号几乎没有失真。最后还采用Mann-Whitney-Wilcoxon检验对该VoIP隐密系统进行安全性分析,分析结果表明该隐密通信系统在统计分析上是不可检测的。(3)提出了一个基于混沌理论的自适应VoIP隐写算法以实现VoIP隐密通信,利用VAPD函数对语音的活动区和非活动区进行判断,解决了PCM语音编解码器中自动识别静音和非静音的问题。根据语音活动特点选择合适的语音作为载体,使得嵌入秘密信息所引起的载体信号变化不容易被察觉,减少隐藏操作对语音质量的影响,避免被攻击者怀疑;利用Logistic混沌映射产生的混沌序列确定隐藏位置,使隐藏位置具有随机性,确保秘密信息的安全性。实验中分别在语音活动区和语音非活动区隐藏信息,每组实验又分别测试隐写算法对女声和男声语音的影响,实验结果说明在语音活动区隐藏信息对语音质量的影响比在语音非活动区隐藏信息小。另外,在Mann-Whitney-Wilcoxon安全检测中,得到原始语音和隐藏语音的样点概率分布是相同的,说明隐写算法能够抵抗统计检测。最后,还与其他隐写算法进行了性能比较,结果表明该隐写算法能达到适中的隐写带宽,这种设计不仅能减少丢包对秘密信息带来的损失,还具有不可检测性。(4)考虑VoIP通信中丢包问题,提出一个基于分形插值的丢包预测模型,并应用在VoIP网络流媒体隐密通信中,目的是减少丢包对VoIP隐密通信的影响,增加隐密通信的鲁棒性。在这个系统中,载体语音信号的选择由丢包预测模型确定,通过丢包预测模型判断一个语音包在特定的丢包网络环境下是否会被丢弃,被丢弃的语音包则不用于隐藏秘密信息。在实验中利用Gilbert丢包模型模拟不同丢包率的网络环境,实验分为男声组和女声组,每组又分别对中文和英文语音进行测试,实验结果表明丢包预测模型的精度越高,鲁棒性越强。然后利用Mann-Whitney-Wilcoxon安全检测验证了该方法具有统计不可检测性分析,而且这种基于分形预测模型的VoIP隐密通信机制能应用在其它的语音编码器的VoIP应用中,具有一定的普适性。
[Abstract]:With the development of network and information technology, the global information technology accelerated, national political and economic information is also gradually digitized, various countries in the energy, transportation, financial, commercial and military fields are dependent on the information network more vulnerable to security threats, secret communication is of great significance to study the.VoIP as a kind of network multimedia real-time service in the military protection and national security, it can provide a low cost and high reliability through the Internet, the global IP service has become the main media of many commercial streaming communication tools. With the use of VoIP more and more widely, the proportion of traffic flow in the VoIP voice data traffic in the network is increasing, while real-time VoIP to avoid the online detection and offline analysis, and it relates to a variety of network communication protocols of each layer, more and more researchers begin to take VoIP as On an ideal carrier for information hiding a secret communication. However, these studies did not consider the real network in all kinds of unstable factors, such as packet loss will lead to incomplete secret information embedded in the voice packet. Moreover, the realization of VoIP secret communication, and the need to consider the real-time VoIP call quality. To solve these problems, this paper considers the network all kinds of unstable factors such as packet loss and delay problems, research on secret communication on VoIP network streaming media contributions are as follows: (1) VoIP in establishing the communication connection stage using key agreement technology based on authentication, the key exchange in VoIP signaling, solve the key distribution problem the VoIP does not affect the quality of speech communication at the same time, the receiving end users can successfully extract and recover the secret information. (2) most of the steganographic algorithm is in the ideal experiment The design and implementation of environment, without considering the network congestion packet loss and other factors on the secret communication, are generally all confidential information is encrypted. But the overall packet loss problem in network inevitably may lead to some loss of the ciphertext, the received ciphertext decryption cannot recover the plaintext correctly. In order to solve the above problems, this paper proposes a VoIP steganography method based on the AES algorithm, the encryption mechanism and embedded synchronization, using AES-128 encryption algorithm, the secret information block encryption, secret information in different voice packets are encrypted, at the receiving end to the secret information can be extracted from voice packets, and decrypt the readable plaintext, so that no one has the secret information embedded voice packet loss, decryption does not affect the other voice packets in the secret information. And through the AES encryption, in ensuring the safety and secret information, as far as possible to reduce the time consumption of the secret information encryption, encryption and embedding are almost at the same time, thereby reducing the time delay. The male and female voice were used as test samples, and the measurement of the speech sample speech quality measurement instrument DSLA II the degree of precision, the experimental results show that compared with the carrier contains secret information hiding speech voice and no secret information embedding signal, almost no distortion. Finally, Mann-Whitney-Wilcoxon is used to test the VoIP secret system security analysis, the analysis results show that the secret communication system is not detectable in the statistical analysis (3). Proposed a VoIP based adaptive implicit chaos theory algorithm to achieve the VoIP secret communication, using the VAPD function of the speech activity area and non active zone For judgment, to solve the PCM speech coding and automatic recognition of silence and non silence problems. According to the characteristics of speech decoder to select the appropriate speech as the carrier, the carrier signal changes caused by embedding the secret information is not easy to detect, reduce the hidden impact on voice quality, avoid being suspected attackers; chaotic sequence generated by Logistic chaotic maps identify hidden location, the hidden location is random, to ensure the security of the secret information. Experiments in speech activities and non speech activities hidden information, and in each experimental group were tested the steganography effect on female and male voice. The experimental results show that the hidden information impact on voice quality in speech activity area than in the non active region of speech information hiding. In addition, the Mann-Whitney-Wilcoxon safety testing, get the original voice and the voice of the kind of hidden The probability distribution is the same, that steganography algorithm can resist the statistical detection. Finally, with other steganography algorithms are compared, results show that the algorithm can achieve moderate write Cain steganographic bandwidth, this design can not only reduce the packet loss of the secret information loss, also can not be detected. (4 considering the problem of packet loss in VoIP communication), put forward a prediction model based on fractal interpolation and application of streaming media, secret communication in VoIP network, the purpose is to reduce the impact of packet loss on VoIP secret communication, increase the robustness of secret communication. In this system, the carrier of speech signal selection by the packet loss prediction model to determine. Through the packet loss prediction model to determine whether a voice packet will be discarded in packet loss environment specific, discarded voice packets are not used to hide secret information. By using the Gilbert model of packet loss in the experiment The different packet loss rate of the network environment, the experiment was divided into male group and female group, each group of Chinese and English speech test, the experimental results show that the packet loss prediction model of higher accuracy, stronger robustness. Then use Mann-Whitney-Wilcoxon safety testing to verify this method with statistical imperceptibility analysis, and based on this the application of VoIP VoIP secret communication mechanism of fractal prediction model can be used in other speech coder in the universal.

【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN916.5;TN918

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