Abstract: Without a fixed infrastructure，Ad hoc networks must distribute intrusion detection among their nodes.A distribute intrusion detection system needs to combine data from multiple nodes to carry out the detection，but the observing nodes may not be reliable.D-S theory of evidence considers the concept of uncertainty，and is well suited for this type of problem.Moreover，Dempster’s role for combination fuse together multiple pieces of evidence from some unreliable nodes.The paper starts with reliability and gives the process of initialization and gives the material analysis of the process of fusing together multiple nodes’data using D-S theory of evidence.

Key words: Ad hoc networks, D-S theory of evidence, intrusion detection, reliability

摘要： 由于Ad hoc 网络没有一个固定的结构，入侵检测只能通过节点进行。一个分布式入侵检测系统需要联合多节点数据进行检测，但是却不能保证这些节点都是可靠的。D-S证据理论考虑了不确定度的概念，可以很好的解决这个问题，更为重要的是，Dempster规则可以从一些不可靠节点融合证据。从可信度入手，给出了初始化过程，并对D-S证据理论融合多节点证据过程进给出了具体的分析。

关键词: Ad hoc网络, D-S证据理论, 入侵检测, 可信度