It extracts data from different users’ historical mobility records and social interactions. a keyword extraction is done to classify the Place of Interest (POI)-related tags, for effective matching with query keywords to reconstruct an effective route for the user.

An access control system with privilege separation based on privacy protection (PS-ACS). In the PS-ACS scheme, we divide the users into personal domain (PSD) and public domain (PUD) logically. In the PSD, we set read and write access permissions for users respectively.