Vulnerabilities and Security Threats in Structured Peer-to-Peer Systems: A Quantitative Analysis

A number of recent structured Peer-to-Peer (P2P) systems are built on top of distributed hash table (DHT) based P2P overlay networks. Almost all DHT-based schemes employ a tight-deterministic data placement and ID mapping schemes. This feature on one hand provides assurance on location of data if it exists, within a bounded number of hops, and on the other hand, opens doors for malicious nodes to lodge attacks that can potentially thwart the functionality of the P2P system. This paper studies several serious security threats in DHT-based P2P systems through three targeted attacks at the P2P protocol layer. The first attack explores the routing anomalies that can be caused by malicious nodes returning incorrect lookup routes. The second attack targets the tight data placement scheme. We show that replication of data items, by itself, is insufficient to secure the data items. The third attack targets the ID mapping scheme. We disclose that the malicious nodes can target any specific data item in the system; and corrupt/modify the data item to its favor. For each of these attacks, we provide quantitative analysis to estimate the extent of damage that can be caused by the attack; followed by an experimental validation and defenses to guard the DHT-based P2P systems and counteract such attacks.