Decentralized Location Privacy Protection Method of Offset Grid

Location services bring convenience to people's lives, but also easily lead to the disclosure of personal privacy information. Many location privacy protection methods are based on trusted anonymous servers, but in real life, the anonymous servers are not trusted. This paper proposes a decentralized location privacy protection method of offset grid for untrusted anonymous servers. The method divides the location area into grids, and the user calculates the offset grid area according to the periodically updated grid information and sends the offset grid area to the anonymous server. The anonymous server selects K-1 distributed grid coordinates according to the history of other user's query, the anonymous grid points set satisfies the multi-diversity. The method in this paper has lower time overhead while protecting user privacy information, and the location distribution of anonymous location sets is more decentralized. Experiments were carried out on the simulated data set. The experimental results verify the effectiveness of the method.