Design And Implementation Of Location Privacy Protection System Based On Social Relations

With the rapid development of Mobile Social Network and intelligent mobile terminals,Location-Based Service not only brings convenience to people but also poses a great threat to their location privacy.However,the state-of-the-art location privacy protection methods ignore the impact of social relationships on location visits.Location privacy may still be compromised once the attacker combined with the social relationships.Therefore,it is valuable to propose a location privacy protection system based on social relationships.Based on the analysis of current location privacy protection methods,the architecture of the location privacy protection system based on social relationships is designed,which is composed of grid division and index module,anonymous location reporting module,anonymous location receiving module,history location request module,history location query module,mobility feature similarity calculation module,friend influence degree measurement module,anonymous location generation module and security evaluation module.The system takes the impact of social relationships on location visits into account when generate anonymous locations to protecting the location privacy.Two strategies are adopted when takes history location and friends' impact as background,which are reuse history location and re-generation location.Mobility feature similarity and common friend ratio and other factors are considered when measure social-relationships' impact.User mobility feature fingerprint is calculated according to the user's trajectory using the SimHash algorithm,then mobility feature similarity is computed by Hamming distance of the mobility feature fingerprints among users.Empirical results show that the security,performance and utility of the system outperforms existing K-anonymous privacy protection methods to some extent.