Continuous K Nearest Neighbor Query Scheme with Privacy and Security Guarantees in Road Networks

There are two key issues in existing LBS privacy preserving query schemes: @1. most solutions based on strong cryptosystem are less practical in road networks, especially inapplicable for continuous query, it leads to efficiency and accuracy declines; most solutions focus on user privacy preservation without considering the data security of server side. In view of the aforementioned issues, we firstly present an encryption and pseudorandom permutation algorithm for the database of LBS with a full consideration of the factors in road networks, this algorithm is a basis to facilitate our query scheme to be implemented in a real scenario, and then we propose the privacy-preserving KNN query scheme based on oblivious transfer, in which the user does not need to provide his actual location or explicit query content, and only obtains one type of POI records each time. By this way, our scheme guarantees both user privacy and server data security, since the data is the server's asset as well. Performance analysis and experiments show that our solution is practical for continuous query in road networks, and achieves a more favorable query efficiency and accuracy compared with existing solutions for KNN queries.