Research On All-dummy-based Location Privacy Protection Algorithm

With the rapid development of mobile devices and social networks,location-based services(LBSs)are becoming more and more widely used in our daily life.Location-based services use location-based technology to provide mobile users with personalized services related to their current location.When using these services,users need to provide their own location to the LBSs provider.Even though LBSs can be very useful,these benefits come at a cost of users' privacy.The users' location information is usually closely linked with the uses' identity information.While real time location could enable an adversary to find you,past data could help adersary discover the user's privacy information,such as home address,company address,personal habits,religion beliefs,etc.Therefore,more and more users focus on the location privacy protection.In order to ensure that users get a good location service quality while protecting their location privacy,k-anonymity is currently the most active research direction for LBS privacy protection.Its main idea is to reduce the resolution of the user's location by generating an anonymous set instead of the user's location.In this paper,we focus on the dummy-based method,which generating anonymous sets based on the dummy address to better protect the user's location privacy without affecting the service quality.The main work includes two aspects as follows:First,this paper proposes a privacy-area aware all-dummy based location privacy algorithm for location-based services.In this paper,we use the advantages of dummy to obtain a large cloaked region in the case of guaranteeing the quality of service.Through location offset to resist border attacks and center attacks to achieve better location privacy protection.Unlike current dummy-based methods,the proposed method no longer uses the user's real location to generate anonymous sets,but uses an anchor to generate an anonymous set.It can effectively avoid the real user in the cloaked region center or boundary.In addition,the anonymous set generated by the proposed method does not contain the real location of the user,which can better protect the user's location privacy.Further,the anonymous set generated by this method needs to satisfy certain conditions,thus ensuring the privacy area.Experimental results show that the proposed method can protect the user's location privacy while ensuring the quality of service.Second,this paper proposes two location privacy protection algorithms based on background information.In order to resist the background information attack,this paper introduces the background information to improve the privacy-area aware all-dummy based location privacy protection algorithm.In this paper,the proposed methods use the background information to calculate the entropy of the positions,and through obtaining larger entropy under the entropy-based privacy metric,to reduce the possibility that adversaries can filter out the user's location.Experimental results show that compared with other algorithms,the proposed methods can guarantee the privacy area,and provide effective location privacy protection.