【作者】 邓美清；

【导师】 彭代渊；

【作者基本信息】 西南交通大学 ， 信息安全， 2015， 硕士

【摘要】 由于无线传感器网络具有低数据率、低能耗和短距离通信等特点,它已被广泛地应用于跟踪和监控系统中,为人们提供了一个便捷监控物理世界的方式。鉴于无线传感器网络使用无线信号进行通信的特点,攻击者可以监听节点发送数据包的情况,并跟踪无线信号,追踪到发送消息的源节点,而源节点通常是距离被监测对象最近的节点,这将暴露被监控事件发生的位置和时间。被监控对象往往是敏感对象,因此,源节点的位置隐私保护是无线传感器网络应用中尤为重要的问题。针对无线传感器网络面临的攻击问题,本文研究能够抵御全局流量攻击的源节点位置隐私保护方案。根据无线传感器网络的特点,引入伪数据包是抵御流量分析攻击的有效方法,然而假包注入会引起较多的冗余通信流量,大量消耗无线传感器节点能量。为了尽可能减少无线通信量,本文分别从假包产生初始和假包转发过程两个角度,设计一种基于能量的源位置隐私保护方案和一个基于全过滤的源位置隐私保护方案。针对FitProbRate方案通信开销较大的问题,本文在其基础上进行改进,设计基于能量的源位置隐私保护方案EBS (Energy-Based Scheme)。一方面,该方案在伪数据包产生阶段,引入能量影响因子、参数基准以及能量影响比重,使节点发送伪数据包的时间间隔受到节点当前电量的影响。另一方面,在时间间隔调整阶段,加入能量影响因子对消息发送间隔均值的影响,重新计算下一个数据包的发送时间间隔。通过理论分析与仿真实验,得到结果表明,本方案保持较短的发送时延,同时,具有更小的通信开销,更能节约节点能量。考虑假包注入会导致网络流量较大的问题,从假包转发过程的角度,设计一种基于全过滤策略的方案AFS (All Filtering Scheme),使网络中所有节点都过滤伪消息,并且节点发送或转发消息都按照既定的频率。在该方案中,节点接收到伪消息时,立即将其丢弃,接收到真消息时,先放入消息缓冲队列,等待一定的时间再发送。通过理论分析与仿真,将本方案与基于代理过滤的方案和普通不过滤的方案进行对比,所得结果表明,本方案更容易部署,具有更少的网络通信开销,能有效地减少网络能耗。更多还原

【Abstract】 Nowadays, wireless sensor networks (WSNs) have been widely used in tracking and monitoring system due to the characteristics of low data rate, low power consumption and short range communication. It provides a convenient way for people to monitor and control the physical world. Because of WSNs using wireless signal for communication, by tracking of wireless signal, adversaries can trace to the source nodes which send out the message. This will also expose the location of a real event and the time it occurs. While the objects that are monitored by wireless sensor networks are usually sensitive objects, it is particularly important to preserve source location privacy in wireless sensor networks.Considering the attacks that WSNs may face with, this paper studies the source location privacy which can resist global attack. According to the characteristic of WSNs, it is the most useful way to resist the flow analysis attack by inserting dummy message. However, wireless sensor node is energy constrained, inserting dummy message will lead to more redundant traffic. To reduce dummy traffic, in this paper, EBS (Energy-Based Scheme) and AFS (All Filtering Scheme) are designed to save energy and network traffic. They are designed from different aspects, one is to reduce dummy message from the source, and the other is to reduce dummy packets during their transmission.Considering the large communication overhead problem of FitProbRate Scheme, this paper designs EBS based on its improvements. On the one hand, this scheme introduces of energy impact factor, parameter benchmarks and energy influence in phase of inserting dummy message, to make dummy message interval affect by the node’s current power. On the other hand, in the interval adjustment phase, consider that energy impact factor will influence on average message interval, recalculate the next message delivery time interval. Through theoretical analysis and simulation experiments, the results show that, this scheme is of short transmission delay, at the same time, it has less communication overhead, can save energy for nodes.Given that dummy message injection can lead to a larger network flow, from the perspective of dummy message forwarding process, this paper designs AFS that all nodes can filter dummy messages. Each node drops the dummy packets as soon as they arrived, while putting the real messages into message queue. After some appropriate time interval, the node will transmit real messages to next hop. Theoretical analysis and simulation are conducted to evaluate the performance of this scheme. This scheme is compared with the Proxy-based Filtering Scheme and the Periodic Collection Scheme. The results show that AFS is more easy to deploy, and has less network communication overhead. It can effectively reduce the energy consumption of the network.更多还原