Information leak in the Chord lookup protocol

In peer-to-peer (P2P) systems, it is often essential that connected systems (nodes) relay messages which did not originate locally, on to the greater network. As a result, an intermediate node might be able to determine a large amount of information about the system, such as the querying tendencies of other nodes. This represents an inherent security issue in P2P networks. Therefore, we ask the following question: through the observation of the network traffic in a P2P network, what kind of information can an adversarial node learn about another node in the same network? We study this question in the case of a specific P2P system - Chord. We also study the effects of the parameters of Chord (such as finger-table size) and the various enhancements to Chord (such as location caching and data caching) on the amount of information leaked.