基于加密数据的位置感知隐私保护模型

针对移动互联网基于位置的服务（LBS）的隐私安全问题，在对已有模型分析研究的基础上，提出了基于加密数据的位置感知隐私安全模型。通过第三方可信服务器对数据库进行加密，实现了服务和隐私之间的平衡。同时采用自主访问控制(DAC)策略，用户可以按照自己的意愿，在保证自己隐私的同时有选择地与其他用户共享数据。最后提出了一种改进的保序加密算法，通过数据转换、桶划分以及线性映射实现了高效的位置感知查询。实验分析表明，该模型实现了位置数据的加密查询和以用户为中心的访问控制策略，改进的算法具有更高的效率。

Privacy-preserving location-aware model based on encrypted data

The privacy-preserving location-aware model based on encrypted data was proposed to solve the privacy and security problems of Location Based Service (LBS) on the basis of survey of existing models. The spatial data was encrypted by the trusted server of a third party to realize the balance between service and privacy. Meanwhile the extended Discretionary Access Control (DAC) policy was implemented in a way that users are able to selectively share their data with others according to their own privacy concerns. Finally the location based queries were realized by using the improved order-preserving encryption algorithm through data conversion, bucket division and linear mapping. Experiments and analysis show that this model enables user-centric access control and queries on encrypted spatial data. The proposed algorithm improves the computational performance.