Effective Multi Keyword Search over P2p Network Using Optimized Bloom Filter Settings

P2P network is a popular technology used for sharing and searching files on the computers connected to the network. Current search mechanisms of peer-to-peer (P2P) systems can well handle a single keyword search problem. Other than single keyword search, multi keyword search is very popular and useful in many file sharing applications. For multi keyword search, the solution which merges the result of each keyword search incurs a lot of data traffic across wide area network .Existing methods use bloom filter (BF), an efficient data structure which is effective in reducing the traffic cost. Though applying BF is not complex, getting optimal results in terms of communication cost is not trivial. In this paper, optimal settings of bloom filter in terms of traffic cost is achieved by the global statistical information of the keywords involved, not by minimizing the false positive rate as claimed by previous studies. We also propose an intersection order optimization strategy based on BF for AND queries to estimate the size of intersection between the sets to minimize the search latency.