Efficient Authentication of Continuously Moving $k$ NN Queries

A moving kNN query continuously reports the k results (restaurants) nearest to a moving query point (tourist). In addition to the query results, a service provider often returns to a mobile client a safe region that bounds the validity of query results in order to minimize the communication cost between the service provider and that mobile client. However, when a service provider is not trustworthy, it may send inaccurate query results or incorrect safe regions to mobile clients. In this paper, we present a framework for authenticating both the query results and the safe regions of moving kNN queries. We theoretically proved that our methods for authenticating moving kNN queries minimize the data sent between the service provider and the mobile clients. Extensive experiments are carried out using both real and synthetic data sets and results show that our methods can perform moving kNN query authentication with small communication costs and overhead.