Improving Resilience against DDoS Attack in Unstructured P2P Networks

In unstructured peer-to-peer （P2P） systems such as Gnutella, a general routing search algorithm is used to blindly flood a query through network among peers. But unfortunately, malicious nodes could easily make use of the search approach launching distributed denial of service （DDoS） attack which aims at the whole network. In order to alleviate or minimize the bad effect due to behavior of malicious nodes using the flooding search mechanism, the paper proposes a Markov-based evaluation model which exerts the trust and reputation mechanism to computing the level of trustworthy of nodes having the information requested by evaluation of the nodes＇ history behavior. Moreover, it can differentiate malicious nodes as early as possible for isolating and controlling the ones＇ message transmitted. The simulation results of the algorithm proposed show that it could effectively isolate malicious nodes, and hold back the transmission of vicious messages so that it could enhance tolerance of DDoS based on flooding in Guutella-like P2P network.