由于结构松散，节点可以动态地加入和退出，安全性问题已经成为P2P网络所面临的主要挑战之一。Tapestry系统中攻击者可以利用系统的软状态机制，污染资源定位指针列表，控制主控端，发起DDoS攻击。基于身份认证的策略可以保护资源定位指针列表不受攻击者的污染，从而预防了DDoS攻击的发生。关键词：Tapestry；分布式拒绝服务攻击；软状态Abstract：Security issues have been one of the chief challenges in P2P networks because of their loose structure and the fact that nodes can join and leave the system dynamically. In Tapestry system the attacker can pollute the object location list and control the handlers to create DDoS attack. A strategy based on identity authentication has been proposed to protect the object location list and to defend the DDoS attack.Key words: Tapestry；Distributed Denial of Service attack；soft-state