基于无线信道特征的体域网安全技术研究

发布时间：2018-01-18 00:13

本文关键词：基于无线信道特征的体域网安全技术研究　出处：《北京邮电大学》2014年博士论文　论文类型：学位论文

【摘要】：随着传感器技术、通信技术和计算机技术的发展和进步,具有感知能力、计算能力和通信能力的可穿戴式传感器节点以及终端设备陆续出现,因此针对这些节点和设备组成的体域网的研究正如火如荼地展开。与传统网络不同,信道开放性、数据敏感性、资源有限性、网络动态性以及应用特殊性是体域网的主要特征。一方面,由于体域网的通信媒介——无线信道是开放性的,攻击者可以通过复制、伪造信息和信息干扰手段,影响数据的正确性。如果攻击者蓄意干扰或更改用户的健康数据,可能会导致医生无法诊断或做出错误的诊断致使病人病情加重甚至死亡。另一方面,无线体域网面临着两类隐私侵犯,位置隐私与信息隐私。由于在无线体域网技术应用中,位置隐私带有高度的个人性,用户的位置信息可能会很容易的被探知。而包括用户各项生理参数的信息,如果不经过隐私保护,这些重要的数据很可能泄露并被第三方接收查看。因此,如何通过以上三种技术实现体域网安全是当前研究面临的主要任务。一般而言,安全问题的研究是从机密性、完整性、可用性、认证和不可否认性这五个角度出发的,而传统网络中的安全技术并不完全满足体域网需求。由于体域网节点少且分布范围小,完整性和不可否认性可以通过身份认证来实现；同时,体域网的资源有限性和网络动态性等特点也对机密性和认证提出了新的挑战；此外,由于体域网信息具有高度敏感性且存在突发紧急情况处理的需求,也为可用性带来了新的挑战。由于这三种安全需求所对应的技术分别是加密、身份认证和访问控制,因此,如何通过以上三种技术实现体域网安全是当前研究面临的主要任务也是基本途径。本文从体域网对安全的需求出发,对体域网节点间的密钥分配、身份认证和外部节点的的访问控制三项技术的核心机制与关键技术进行了研究,具体包括以下内容：(1)针对资源有限性和网络动态性迫使体域网必须具有高效的轻量级加密以满足机密性的要求,提出了一种基于小波变换趋势的无线体域网密钥协商机制(Wavelet-Transform Trend-Based Key Extraction, WTKE)。首先,WTKE充分利用了体域网通信节点间在信道相干时间内RSS(ReceivedSignal Strength)相互测量值的高相关性,通过4级Haar小波变换后进行趋势量化,使得体域网节点间即使有窃听者的存在也可以共享密钥。其次,WTKE的安全性通过了实验验证,窃听节点Eve和合法节点(Alice或者Bob)之间的密钥偏差比接近于0.5,这和Eve通过随机猜测每一位密钥的概率是一样的。WTKE生成密钥通过了NIST test suite检验,证明密钥满足随机性要求。然后,本文在密钥生成速率和密钥偏差率两个指标上,将WTKE和经典的幅度量化方法以及传统的趋势量化方法进行对比,结果表明：和幅度量化方法相比,WTKE都具有优势；和之前的趋势量化方法相比,WTKE通过降低密钥生成速率来降低密钥偏差率。最后,在引入足够运动的前提下,WTKE同时也可以应用于节点和basestation间,本文也做了类似的实验进行验证。综合来看,WTKE是一种低资源消耗、低硬件复杂度的轻量级密钥协商机制。 (2)针对网络动态性要求体域网必须具备快速简单的身份认证以满足认证的要求,提出了一种针对体域网的轻量级近距离身份认证机制(RSSRatio-Based Node Authentication, R2NA)。R2NA没有额外添加硬件使用带外信道,而是充分利用了无线信道的物理特征：当发送端距离体域网控制单元(Control Unit, CU)或者一个体域网传感器节点足够近时,发送端和CU间RSS值、与发送端和传感器节点间RSS值差别很大,而远距离的发送端是不可能产生这种大的差值的。首先,本文通过理论推导分析和实验数据验证了R2NA机制的原理。其次,本文探讨了可能影响R2NA机制的因素,包含传感器穿戴位置、人体移动、环境和人体体型,综合考虑后,给出了R2NA机制相关参数。最后,本文通过实验分析了R2NA的安全性,和之前基于无线信道特征的体域网节点认证机制BANA (Body Area Network Authentication)在性能上进行了对比,结果表明：R2NA在速度、能耗和适用性这3个指标上优于BANA,在兼容性和易用性这2个指标上和BANA一样；依据本文中的参数设置,R2NA的认证时间不超过12秒,在0.2m范围内的认证成功率接近100%,且R2NA可以适用于多种拥挤场景。 (3)针对资源有限性与应用特殊性要求体域网必须有松紧耦合的访问控制以满足可用性的需求,提出了一种基于情景自感知的松紧耦合型访问控制机制,即体域网会在正常情况下需要严格的访问控制机制,而在紧急情况下需要相对宽松的访问控制机制。为了实现情景自感知,外置网关CU利用加速度计测量人体加速度信号,并通过贝叶斯方法实现跌倒识别,从而判别情景区分紧急与否,进行不同访问控制机制切换。在访问控制技术上,针对多种不同场景的安全需要,本文提出了两种模式的通信方案,使得CU可以主动切换访问控制机制或通过干扰进行被动防御,从而可以实现不同情景之间的安全切换。本机制还引入了基于Fuzzy Vault(模糊金库)的密钥协商机制(Fuzzy Vault based Key Distribution, FVKD)来保障普通模式的通信机密性,同时在普通模式利用R2NA,以及在被动紧急模式下关闭CU来判别近距离属性进行认证确权。最后,本文通过实验分析了提出的访问控制机制的安全性：在CU正常穿戴在身上工作时,即使其干扰功率比普通传感器节点传输功率低20dB,仍然可以防御攻击者的攻击。随着体域网大规模的应用,体域网安全必将引起人们更多的关注,本文利用无线信道物理层特征提出的上述轻量级解决方案对有效提高体域网安全性具有重要意义。
[Abstract]:With the development of sensor technology, communication technology and computer technology development and progress, with perception, computation and communication capabilities of wearable sensor nodes and terminal devices have appeared, so the research on network, the nodes and components is carried out like a raging fire. Different from the traditional network, channel opening. Data sensitivity, LIMITED resources, dynamic network and special application is the main feature of the network. On the one hand, because of the network communication media, wireless channel is open, the attacker can pass the copy, false information and information interference means, influence the accuracy of the data. If the attacker deliberately health data interference or change user, may cause the doctor couldn't make the wrong diagnosis or diagnosis of the patient illness and even death. On the other hand, wireless body area network is facing Two types of invasion of privacy, location privacy and information privacy. Due to the application of wireless body area network technology, with a highly personal location privacy, location information of the user can easily be detected. The information includes the physiological parameters of the user, without privacy protection, these important data may be leaked and by the third party receiving view. Therefore, how to through the above three kinds of technology to realize the body area network security is the main task of current research faces.
Generally speaking, the research on security is from the confidentiality, integrity, availability, authentication and non repudiation of the five point of view, the traditional security technology in the network does not fully meet the needs of the network. Because the body area network node is less and the distribution range is small, integrity and non repudiation. Can be achieved through the identity authentication; at the same time, the network characteristics of the limited resources and network dynamics and also brings new challenges to confidentiality and authentication; in addition, the body area network information with high sensitivity and emergency handling requirements, it also brings new challenges to the availability. Corresponding to these three kinds of security requirements are encryption technology, identity authentication and access control, therefore, how to through the above three kinds of technology to realize the body area network security is the main task of current research is also facing the basic way.
This article from the body area network security needs, the key distribution area network nodes, identity authentication and external node access control technology three core mechanisms and key technologies are studied, including the following: (1) according to the limited resources and the network dynamic force body area network must with efficient lightweight encryption to meet the confidentiality requirements, proposes a wireless body area network key negotiation mechanism based on the trend of wavelet transform (Wavelet-Transform Trend-Based Key Extraction, WTKE WTKE). First, make full use of the body area network communication between nodes in the channel coherence time RSS (ReceivedSignal Strength) high correlations between measured values the 4 level through Haar wavelet transform trend quantization, make appropriate network nodes domain even with the presence of the eavesdropper can also share key. Secondly, the safety of WTKE by the Verified, the eavesdropper Eve and legitimate nodes (Alice or Bob) between the key deviation ratio close to 0.5, and the Eve by random guessing probability of every key is.WTKE key generation like NIST test through suite test, prove that the key to satisfy the requirements randomness. Then, based on the key generation rate and key the deviation of the two indexes, compared to the amplitude quantization method and classical WTKE and the trend of traditional quantitative method results show that: compared with the amplitude quantization method, WTKE has the advantages of quantitative methods and compared; trend before, by reducing WTKE key generation rate to reduce the key rate of deviation. Finally, based on the introduction of enough the campaign, WTKE can also be applied to the nodes and basestation, this paper has done a similar experiment. On the whole, WTKE is a kind of low resource consumption, low hardware complexity Lightweight key negotiation mechanism.
(2) according to the requirement of network dynamic authentication body area network must have quick and easy to meet the certification requirements, a method is proposed for network distance lightweight authentication mechanism (RSSRatio-Based Node Authentication, R2NA.R2NA) without extra hardware to use out of band, but make full use of the physical characteristics of the wireless channel the sending end distance: when the body area network control unit (Control Unit CU) or a personal area network sensor nodes close enough, the sender and the CU RSS value, the difference and the sending end and the sensor nodes RSS, while the transmitter distance is unlikely to produce such a big difference. First of all, this paper verified the principle of the R2NA mechanism through theoretical analysis and experimental data. Secondly, this paper discusses the factors that may affect the R2NA mechanism, including position sensor, wearable human movement, environment and people Body, after comprehensive consideration, given the relevant parameters of the R2NA mechanism. Finally, this paper analyzes the security of R2NA by experiment, and before the body area network node based on BANA authentication mechanism in the wireless channel characteristics (Body Area Network Authentication) were compared in terms of performance, the results show that R2NA in speed, the 3 indicators energy consumption and applicability is better than BANA, the compatibility and usability of these 2 indexes and BANA; based on the parameters in this paper set up R2NA authentication time is not more than 12 seconds, in the range of 0.2m authentication success rate close to 100%, and the R2NA can be applied to a variety of crowded scenes.
(3) for the access control of the limited resources and the application requirements of body area network must have tightly coupled to meet the usability requirements, proposed a scenario based elastic coupling type self aware access control mechanism, namely the body area network would normally require strict access control mechanisms and needs the relatively loose access control mechanism in case of emergency. In order to achieve situational self perception, the external CU gateway using the accelerometer to measure the body acceleration signal, and the Bayesian method to determine fall recognition, emergency situation distinction or not, different access control mechanism in switch. Access control technology, according to the security needs of a variety of different scenes in this paper, the communication scheme of two modes, so that CU can active handoff mechanism of access control or passive defense by interference, which can realize different scenarios The safety switch. This mechanism is introduced based on Fuzzy Vault (fuzzy vault) key negotiation mechanism (Fuzzy Vault based Key Distribution, FVKD) to protect the confidentiality of communications in the normal mode, while using R2NA in normal mode, and the closure of CU in passive emergency mode to determine the authentication right close attributes. Finally, this paper analyzes the security of the proposed access control mechanism through the experiment: CU in normal wear on the body, even if the interference power is 20dB lower than the ordinary sensor nodes transmit power, still can defend the attackers.
With the large-scale application of body area network, the security of body area network will cause more attention. This lightweight solution proposed by using the physical layer characteristics of wireless channel is of great significance for improving the security of body area network effectively.

【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN918.4

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