We present Juxtaposed approximate PageRank (JXP), a distributed algorithm for computing PageRank-style authority scores of
Web pages on a peer-to-peer (P2P) network. Unlike previous algorithms, JXP allows peers to have overlapping content and requires
no a priori knowledge of other peers’ content. Our algorithm combines locally computed authority scores with information obtained
from other peers by means of random meetings among the peers in the network. This computation is based on a Markov-chain state-lumping
technique, and iteratively approximates global authority scores. The algorithm scales with the number of peers in the network
and we show that the JXP scores converge to the true PageRank scores that one would obtain with a centralized algorithm. Finally,
we show how to deal with misbehaving peers by extending JXP with a reputation model.
Keywords Link analysis - Web graph - Peer-to-peer systems - Social reputation - Markov chain aggregation
Partially supported by the EU within the 6th Framework Programme under contract 001907 “Dynamically Evolving, Large Scale
Information Systems” (DELIS).