针对LBS中非可信用户协作构建匿名域的研究

基于位置的服务作为一种不断发展的新型服务模式，为人们的生活带来了极大的便利。但另一方面，用户的位置隐私也受到了很大的威胁。从LBS位置隐私保护的实际应用出发，根据现有的位置隐私保护模型，分析了在用户协作构建匿名域的方式下，用户非完全可信时，位置隐私面临的威胁，提出了User-Cooperation Security（UCA）匿名算法，在P2P空间匿名算法的基础上引入数字签名技术，实现用户之间的身份认证，并且在通信过程中，用接收方的私钥加密位置信息，避免了攻击者窃取他们的位置信息。算法中还加入了用户可以容忍的最大等待时间这一参数，通过等待一段时间重新进行节点发现，有效地提高了匿名成功率。通过实验验证，该算法可以更好地保护用户的位置隐私。

Research on incredible users cooperate constructing anonymous region in LBS

As a new service model, location-based service brings people great convenience. But, users’ location privacy is facing a lot of threat. According to the actual application on location privacy protection in LBS and the existing privacy protection model, the paper analyzes the threat when using the method based on users’ cooperation to protect location privacy and the users are not fully confidential, and proposes an algorithm called User-Cooperation Security（UCA） spatial algorithm. The algorithm introduces digital signature into the peer-to-peer spatial cloaking algorithm, so that users can realize the identity authentication with others and encrypt the sensitive messages with the private key of receiving party before they send them, avoiding the attackers stealing their position. Besides, the algorithm can discover more nodes when the users broadcast discovering messages again after a little time. Through the experiment, the algorithm is proved that it can protect users’ location privacy better.