CoPrivacy:A Collaborative Location Privacy-Preserving Method without Cloaking Region

Serious location privacy problems arise with extensive application of location-based services.Nowadays,location k-anonymity is the one of the most popular location privacy-preserving methods,it requires a trusted third party as an anonymity server which is proved to be the performance bottleneck and aim point of attacks.In addition,it complicates the query processing by requiring an anonymity region instead of a point.This paper proposes a collaborative location privacy-preserving method without anonymity server and cloaking region.Anonymity groups are formed through user's collaboration,members in the group regard density center as their locations when requiring for LBS,and acquire kNN results incrementally from the service provider.At last,group members get the precise results through computing distances between their locations and the kNN results.The proposed method achieves k-anonymity without cloaking region,the efficiency of anonymity is improved,and query processing is simplified.Extensive experimental results show advantages of the proposed method.