中文摘要：

基于位置服务（LBS）在给人们带来方便的同时也引起了越来越多的安全隐患，位置隐私保护成为了学术界和业界关注的焦点。由于大部分用户是沿着道路交通网络移动，研究路网环境下的位置隐私技术更具有现实意义。通过分析路网环境面临隐私泄露的新挑战，从网络扩张匿名技术、X-Star匿名技术、Mix zone匿名技术三个方面对现有路网下的位置隐私技术进行了深入研究，比较了其隐私水平、服务质量等性能指标。最后，总结了路网环境下位置隐私保护技术存在的问题及未来的研究热点。

英文摘要：

Location-based services （LBS） have brought the convenience, but also causes a safety hazard for users, location privacy protection has become the focus of the academia and industry. Since most users are moving along the road network, so the research on location privacy over road networks is more practical significance. By analyzing the network environment is facing new challenges in loss of privacy, from three existing classic location privacy including network expansion, X-Star and Mix zone anonymous, this paper in-depth studied their performance indicators included level of privacy, quality of service and etc. Finally, the paper concluded the problem remaining and development focus of the location privacy protection technologies over road network.