RChord: an enhanced Chord system resilient to routing attacks

In this paper, we propose a variant of Chord system that is resilient to routing attacks. By routing attacks, we mean the attacks which detour the looking up messages, aiming to disrupt the performance of data look-up systems by increasing the path length of queries. Chord routes messages unidirectionally and has no bidirectional edges. While its performance in the absence of routing attacks is acceptable, it degrades dramatically under routing attacks. Following this observation, we introduce the concept of reverse edges to the Chord system. We named the new Chord system as RChord. We propose several deterministic and randomized algorithms to construct reverse edges. We design a routing algorithm for the new system, which is simple, efficient and backward compatible with the original system. We then analyze the performance of the RChord under routing attacks. We find that its performance is significantly improved in terms of average path length, even by adding very few reverse edges.