【作者】 崔莹；

【导师】 王箭；

【作者基本信息】 南京航空航天大学 ， 计算机应用技术， 2007， 硕士

【摘要】 Ad Hoc网络由一群可移动装置临时组成,不需固定基础设施,能够快速、动态、简单组网并相互沟通,在诸如军事设施、Ad Hoc移动会议、医疗以及日常生活等诸多方面都有广泛应用。同时,Ad Hoc网络的固有特性使其易于遭受攻击,因此安全是Ad Hoc网络能够获得更广泛使用的关键。其中,路由安全则是Ad Hoc安全的基础。如果能够有效地区分并隔离恶意节点,显然可以大大提高Ad Hoc路由的安全。本论文拟采用信任度评价方法来区分恶意节点,在广泛使用的路由协议(AODV)中引入信任度模型来弥补其设计上的安全漏洞,并提出一个以信任度为基础的安全路由协议(TAODV)。本协议利用节点的通信历史记录,包括邻居节点间通信成功与通信失败的次数,计算其对邻居节点的信任度。在路由过程中,利用此信任度来计算路径信任度,路径选择则以路径信任度最大为准则,并用信任度来限制对应邻居节点的行为。当邻居节点信任度低于设定阈值时,则判为恶意节点。在路由过程中避开这些恶意节点,以减少恶意节点的影响,增强路由的安全性。本文分析了该协议在常见攻击下的行为及其对攻击的抵抗能力,与已有算法(ARAN/SAODV)相比具有较高的安全性和较高的网络性能。同时进行了模拟实验,以仿真工具NS2来评估TAODV在遭受攻击的情况下,网络传输的整体性能。与ARAN/SAODV协议相比较,实验结果表明,TAODV能够降低恶意节点的攻击,在网络的性能上具有较高的分组投递率和较小的网络延迟及网络负载。更多还原

【Abstract】 Ad Hoc network is comprised of a number of mobile devices, and can be quickly, dynamically and easily set up without fixed network infrastructure, and it has various applications in many fields, e.g. military facilities, mobile Ad Hoc meeting, medical care, and other aspects of daily life. But due to its intrinsic characteristics, Ad Hoc network is vulnerable to various malicious attacks. Thus, security is the key basement that Ad Hoc can be widely deployed, and routing security is fundamental to Ad Hoc network security.Apparently, recognizing and isolating malicious nodes will certainly enhance the security of Ad Hoc network. This paper takes advantage of trust measurement to recognize and segregate malicious nodes, introduces the idea of trust measurement to widely-acceptable routing protocol (i.e. AODV) to make up its secure routing design defects and proposes a secure routing protocol based on trust measurement (called as TAODV in short). Here, each node determines its neighbor’s trust measurement according to the success probability of previous communications. Based on it, the paper also defines a route’s trust measurement which is employed as a criterion to choose a route, and limit neighbor nodes’actions by their corresponding trust measurements. A node will be regarded as malicious when its trust measurement is below a previously-determined threshold. And by this way, those malicious nodes determined will be kept away during routing request and reply so that its malicious attack can be avoided. The paper discusses and analyzes the resistance ability of the proposed protocol when facing various familiar attacks and shows it is more secure and has better routing performances compared to previous secure routing.The paper also takes some simulating experiments. Here, use the network simulation tool NS2 to estimate performance of network transmission of TAODV under attacks. The experimental results show that compared to SAODV and ARAN protocols, TAODV has a higher Packet delivery Ratio, a smaller End-to-End Delay and network routing loads besides reducing the impact from malicious nodes.更多还原