Access control models for geo-social computing systems

A Geo-Social Computing System (GSCS) allows users to declare their current locations, and uses these declared locations to make authorization decisions. Recent years have seen the emergence of a new generation of social computing systems that are GSCSs. This paper proposes a protection model for GSCSs. The protection system tracks the current locations of users and a knowledge base of primitive spatial relations between locations. Access control policies can be formulated by the composition of primitive spatial relations. The model is extended to account for Geo-Social Network Systems (GSNSs), which track both a spatial knowledge base and a social network. A policy language for GSNSs is proposed for specifying policies that combine both social and spatial constraints.