Research On Location Privacy Protection Scheme Based On Location Semantics

With the widespread application of mobile smart devices and wireless positioning technologies,Location-based service(LBS)has become an important part of users' daily life.With LBS mobile users can obtain a variety of services,such as navigation and finding nearby points of interest,etc.However,while enjoying the convenience of LBS,mobile users are vulnerable to the threat of location privacy leakage,because users need to provide relevant queries and location information when obtaining these services,and this information is often sensitive to users,so LBS privacy protection has become a research hotspot in the field of information security.Most of the existing location privacy protection schemes do not consider the semantic information of the location,and malicious attackers can obtain the user's sensitive information through semantic inference,which can lead to the leakage of user privacy.According to users' needs for location semantic difference and anonymous set sensitive semantic security,this paper proposes the following two location privacy protection schemes based on location semantics using k-anonymity model.First,aiming at the problem that the current dummy location privacy protection schemes don't fully consider that the attacker has background knowledge such as location semantics,this paper proposes a dummy location selection scheme that resists background knowledge attacks.This scheme uses a tree structure to organize all locations,calculates the semantic distance according to the number of hops between location nodes,and uses this to measure the degree of location semantic difference.The generated dummy location set not only meets the semantic difference,but also the query probability between positions is as close as possible and scattered on the map as much as possible to effectively resist background knowledge attack.Finally,the proposed scheme is compared with existing schemes through simulation experiments,and the effectiveness of the scheme is verified.Second,aiming at the problem that k-anonymity and l-diversity are only considered when generating anonymous set in the road network environment,which is easy to cause sensitive semantic information leakage,an anonymous set construction scheme to protect sensitive semantic is proposed based on the road network environment.In this scheme,mobile users can customize sensitive semantic types,which reflects personalized anonymity.At the same time,in order to prevent the leakage of sensitive semantics in anonymous set,the popularity of each semantic location is fully considered,and the ratio of the sum of popularity of sensitive semantic locations in the generated anonymous set to the sum of popularity of all semantic locations is less than the threshold value .The scheme not only protects the user identity but also realizes the sensitive semantic security of the anonymous set.Finally,the performance of the scheme is verified by simulation experiments,and the results show that the scheme has better performance.