基于优化信任评估的Ad Hoc安全路由协议

针对Ad Hoc网络中自私节点造成的攻击问题，提出了一种基于信任评估的Ad Hoc安全路由协议TEAR。该协议在节点行为信任评估方案的基础上，通过使用链路信任值和路径信任值表示节点和路径的可信度，同时，在链路信任值计算时，引入了基于公共邻居节点的间接信任评估方法和可变时间窗机制，保证了信任值计算的准确性和实效性；协议中每个节点维护一张信任表，并重新定义了路由请求和路由回复消息格式，实现了安全路径的快速选择。使用NS2进行模拟验证，又与AODV以及基于固定时间窗信任评估的安全路由协议TA-AODV进行性能对比。结果表明，改进的信任评估方案具有更好的性能，采用该方案的安全路由协议能较快地发现自私节点，并准确选择安全路径，提高了Ad Hoc网络性能。

Secure routing protocol based on optimized trust evaluation in Ad Hoc network

Aimed at the attack of selfish nodes in mobile Ad Hoc networks, this paper proposes a secure routing protocol TEAR, which is based on trust evaluation. In order to realize the accuracy and timeliness of trust values, the proposed protocol, which is based on the trust evaluation scheme of node behavior, uses the link trust and path trust to represent the reliability of a node and a path respectively, and introduces the indirect trust evaluation scheme with public neighbors' trust values and variable time window. The trust value table of each node and the new structure of RREQ and RREP provide the quick selection of secure routing. Finally, TEAR protocol was verified by NS2 simulation and compared with AODV and TA-AODV which is based on fixed time window trust evaluation. The simulation results show that the improved trust evaluation scheme has a superior performance, and TEAR can not only detect the selfish nodes correctly but also select secure path, which improves the function of Ad Hoc networks.