A Bloom Filter-Based User Search Method Based on Movement Records for P2P Network

In this paper, we propose a P2P user search method based on movement records that can be automatically obtained by location detection devices. We assume movement records are treated as a sequence of pairs of spot ID and time and they are stored in a peer for each user. In our proposal, a Bloom Filter is applied to each spot ID and time to combine all movement records for one user as a fixed length bit array. To search a user who followed specified course, we propose a AND/OR search method based on Bloom finger table (BFT), which extends a routing table of a Chord DHT system to retrieve elements using Bloom filter. By this method, user searches based on a sequence of locations with or without time can be realized efficiently. Additionally, in order to reduce the number of messages for a user search, we propose a peer-ID assignment for BFT based on user´s geographical foothold. The number of messages for a user search can be reduced by this peer-ID assignment since users who visit same places are located closer to each other on the routing table. Evaluation results of simulations show that our proposal reduces the number of messages compared to a naive implementation using existing P2P retrieval method.