Secure routing for structured peer-to-peer overlay networks

TLDR

Structured peer‑to‑peer overlays enable large‑scale decentralized applications and are highly resilient, yet they lack security; a small number of malicious nodes can disrupt message delivery, a problem especially acute in open systems without preexisting trust. This work investigates attacks that prevent correct message delivery in structured overlays and proposes defenses against them. The authors describe techniques that allow nodes to join the overlay, maintain routing state, and forward messages securely even when malicious nodes are present. Evaluation of these techniques shows that secure routing can be achieved despite the presence of malicious nodes.

Abstract

Structured peer-to-peer overlay networks provide a substrate for the construction of large-scale, decentralized applications, including distributed storage, group communication, and content distribution. These overlays are highly resilient; they can route messages correctly even when a large fraction of the nodes crash or the network partitions. But current overlays are not secure; even a small fraction of malicious nodes can prevent correct message delivery throughout the overlay. This problem is particularly serious in open peer-to-peer systems, where many diverse, autonomous parties without preexisting trust relationships wish to pool their resources. This paper studies attacks aimed at preventing correct message delivery in structured peer-to-peer overlays and presents defenses to these attacks. We describe and evaluate techniques that allow nodes to join the overlay, to maintain routing state, and to forward messages securely in the presence of malicious nodes.