Privacy Preserving in Cloud Environment for Obstructed Shortest Path Query

With the prosperity of location-based services, shortest path query became one of the most common services, and provided convenience for finding the best way to arrive at the destination of users. However, in order to obtain the service, users had to submit the current locations to a data owner, and this process may pose privacy threats to users. More seriously, if the data owner outsourcing the query data to a cloud server for calculating the shortest distance, users' privacy may be leaked even further. To cope with the problem of outsourcing computation, based the homomorphic encryption and secure multiparty computation, this manuscript presents a framework to reduce the likelihood of private information leakage, and privacy preservation of both the user, and the data owner. In this framework, two different conditions were considered, and the shortest path was computed with or without obstruction on the road. Thereafter, two protocols called query with obstruction and query without obstruction are presented.