Structured P2p Network Dos Attacks

Peer-to-peer (P2P, in short) network technology has improved quickly in the recent years. The structured P2P network such as Tapestry,Pastry,Chord,CAN, are gain quite a lot of attention, because they have many predominances such as the good scalability and the property that can locate the object in finite hops.The structure of P2P network is loose, the node can join and leave the network dynamically, so the system is highly undetermined and randomly. Usually, the peer can not know the identity and reliability of the peer which is communicating with. Security issue has been one of the important problems that limit the P2P network going further and being used in more areas.In this paper, we try to study how the attacker can attack the network and the method that can prevent, detect and suppress the DoS (Denity of Service, DoS) attack in the structured P2P network.We show that the structured P2P network will surfer the DDoS (Distributed Denity of Service, DDoS) attack in the overlay except the traditional attack that coming from the network layer. The attacker can exploit the "soft-state" maintenance mechanism of the local index and routing table in the structured P2P systems to create the DDoS attack in the overlay. The strategy based on authentication of ACK message and public key encryption method has been proposed to protect the local index and routing table and to prevent the DDoS attack.We propose a method that can detect the attack in distributed way based on the fact that the routing of message in the structured P2P network follows the tree model. This method can trace the attack as near the attacker as possible. The node near the attacker will suppress the attack. Thus, the attack can be alleviated. The node which suppressing the attack will suppress the attack according to the intensity of the attack self-adaptively. It will suppress the attack effectively as well as reduce the effect of other nodes near the attacker and maintain the efficiency of the network.