Denial-of-service (dos) attacks and commerce infrastructure in peer-to-peer networks (draft)

This dissertation studies denial-of-service (DoS) attacks in peer-to-peer (P2P) networks, and electronic commerce infrastructure for such networks. In the first part of this dissertation, we propose attack containment techniques that make search and resource discovery protocols in P2P networks more resilient to DoS attacks. We describe the importance of attack containment as a complement to prevention, detection, and recovery techniques. We describe a simple but effective traffic model that can be used to understand the effects of application-layer, query-flood DoS attacks in P2P networks. We develop a threat model that describes how good and malicious nodes are captured by the traffic model, and we describe the results of simulations based on the model. Simulations are run on both synthetic and real Gnutella network topologies, and on the Chord distributed hash table network. We analyze how different query acceptance policies can contain the effects of query-flooding DoS attacks. We also describe a DoS attack against the resource discovery mechanism of a P2P protocol called GUESS. Nodes in a GUESS network use a data structure called a pong-cache to keep track of other nodes in the network, and malicious nodes can “poison” pong-caches with malicious node ids. We describe how to contain such attacks using an ID smearing algorithm and a dynamic network partitioning scheme. In the second part of this dissertation, we develop an architecture that can be used to support electronic commerce in a P2P network. We report on a prototype implementation of the architecture that allows mobile and wireless devices to make purchases using a digital cash scheme called PDA-Payword.