Efficient and Privacy-Preserving Subgraph Matching Queries in Graph Federation

Graph technology has been attracting interest due to its ability in modeling complex network and real-world relationships in various applications. Subgraph matching queries are useful tools that can be used to extract structural insights from graph dataset. As the accuracy of subgraph matching queries increases with graph size, it is natural to consider providing subgraph matching query services over a graph federation, which can form a larger graph by combining graphs from multiple data owners. However, the downside combining data is that it may provoke privacy concerns related to the graph datasets and user queries. Although many schemes have been proposed for privacy-preserving subgraph matching queries, they either cannot be extended to graph federation scenarios or do not consider query privacy. Aiming at this challenge, in this paper we construct an efficient and privacy-preserving subgraph matching query scheme in graph federation with two data owners. In the proposed scheme, the two data owners jointly compute the neighboring signatures of all vertices without disclosing their graph datasets to each other. Upon receiving a subgraph matching query, the data owners together respond with a subgraph which includes all subgraphs matching the pattern in the combined graph. Security analysis shows that our proposed scheme can well preserve data and query privacy. Extensive experiments further demonstrate that the scheme is efficient in terms of computation and communication.