Abstract: When the Mobile Ad Hoc Network (MANET) is widely used in many areas nowadays, the research on security of MANET is becoming more and more important. DDoS attacks have brought very serious threats to the MANET, as well as to the wired network. Because of the peculiarity of the MANET, the research for DDoS attacks in MANET is much more different from that in wired network. This paper first describes security problems in MANET, and then lists the DDoS attacks in the physics layer, MAC layer, network layer, and transport layer. At the same time, we also introduce the state of the art of defense mechanisms against the challenge of each kind of DDoS attacks. At last, some instructive suggestions about how to form a secure MANET against the DDoS attacks have been given.

Key words: Denial-of-service Attack, Distributed Denial-of-service Attack, Mobile Ad Hoc Network

摘要： 随着移动自组织网络在各个领域内得到广泛的使用，其安全性研究显得越来越重要。DDoS攻击给有线网络造成了很大的威胁，同样也威胁到了移动自组织网络的安全性。由于移动自组织网络和有线网络存在着结构型差异，因此移动自组织网络中的DDoS攻击研究与有线网络中的DDoS攻击研究有较大的不同。本文首先描述了移动自组织网络的安全状况；然后从移动自组织网络的网络架构出发，分别分析移动自组织网络中针对物理层、MAC层、网络层以及传输层的DDoS攻击，同时总结针对不同网络层次的攻击所需要采取的防御措施；最后为移动自组织网络建设过程中就如何防范DDoS攻击提出参考意见。

关键词: 拒绝服务攻击, 分布式拒绝服务攻击, 移动自组织网络