【作者】 李江；

【导师】 谭长庚；

【作者基本信息】 中南大学 ， 计算机应用技术， 2009， 硕士

【摘要】 作为对基于密码体系的安全手段的重要补充,信任机制对移动自组网的可靠运行和安全保障具有重要意义。但由于信任关系的建立有赖于第三方节点的推荐,虚假推荐和不推荐行为是信任机制本身必须解决的问题。本文主要研究基于信任机制的移动自组网中激励节点诚实推荐的问题,并在此基础上实现可信路由协议。本文首先以移动自组网中典型的按需路由协议为基础对节点的路由协作行为进行分析,接着从主动攻击和被动攻击两个方面介绍移动自组网路由面临的安全问题,然后总结了现有的典型的安全路由协议和信任管理系统。针对不良节点策略性的虚假推荐和不推荐行为,本文提出一种基于推荐的信任模型,用推荐信任值和容忍度来评价节点的推荐行为;引入时间帧和滑动窗口进行信任值合成计算,使用两个时间因子以保证信任值的时效性和可用性;提出一个低开销的信息共享机制用于节点间交换经验信息。最后以基于推荐的信任模型为基础,在DSR协议上实现一种移动自组网中基于推荐信任的可信路由协议:源节点需要对路由中所有节点可信;中间节点需要对其上一跳节点、下一跳节点、源节点以及目的节点可信;目的节点需要对其上一跳节点以及源节点可信。可信路由协议的实现有效结合了DSR协议按需操作的特性。仿真结果表明本文提出的模型能够有效解决不良节点的虚假推荐和不推荐问题,具有较好的动态适应能力。更多还原

【Abstract】 As an important supplement to cryptography based security solutions, trust management plays an important role in security and reliability of mobile ad hoc networks. However it can be cheated by the propagation of rumor produced by malicious or selfish node for using second-hand observation. This paper mainly discusses how to inspirit nodes to provide honest recommendation, and then propose a trust routing protocol based on recommendation and trust for MANET.Based on the analysis of the MANET on-demand routing discovery mechanism, this paper surveys the cooperation behavior between the relative independence entities, and analysis the security issues of MANET from Passive Attacks and Active Attacks, then addresses the existing typical research on the security schemes, security routing protocols and trust management mechanisms are included, and makes a comparison and discussion of their respective merits and faults. To detect dynamic false recommendation and non-recommendation behavior of harmful nodes in MANET, this paper presents a trust model based on recommendation mechanisms, evaluates the recommender’s feedback by the recommendation trust value and toleration, provides a concrete and reasonable formula of trust value by the use of time-frame and sliding windows, guarantees the timeliness and availability of trust value by the use of two fading factors, and a low-cost recommendation technique is provided for nodes to share experience information. Finally, we propose a trust routing protocol based on recommendation and trust for MANET with appropriate modifications to DSR. Through the theoretical analysis and simulated experiments, the rationality and the feasibility of this trust model is further confirmed.更多还原