Research On User Trajectory Privacy Protection In Crowdsensing Network

With the development of mobile smart devices and the Internet,Crowd Sensing has become an emerging method of data collection.It can effectively solve some problems of traditional sensor networks,such as high cost,difficult maintenance and poor scalability.Users in the crowd sensing use their moblie smart devices for data perception,and accomplishes large-scale data collection tasks by collaboration among users.However,crowd sensing has the problem of user privacy in the practical application.In the specific crowd sensing network application,users not only need report the perceived data,also report spatio-temporal information.These data has a lot of sensitive user information,and once these data breach would be a serious threat to the privacy of users.User privacy protection has become an important factor restricting the development of crowd sensing networks.The main content of this thesis is the trajectory privacy problem of users in the crowdsensing network.For the problem of user information privacy leakage caused by location information leakage in urban roads,this paper proposes the challenges of personalized user privacy measurement,city coverage and data availability.The data collection scheme based on the selection of the road segment can protect the user's track privacy while ensuring high precision of the data.The main work of this thesis is as follows:(a)We construct the data collection model of crowdsensing network with the trusted third parties.Combined with the particluarity of vehicle user location information,this thesis proposes a data reporting scheme based on road segment selection,and difine how the user's trajectory privacy strength is measured.Meanwhile,the trusted third party is used to remove redundant data,enhance the privacy protection of the user,and ensure the coverage of the perceived data in the city map.(b)Taking the classic crowdsensing data collection model as an example,a differential privacy-based trajectory privacy protection scheme is proposed to solve the user's trajectory privacy leakage,which caused by the correlation between urban segments.The probability of the user's real trajectory is quantified,and the privacy protection strength is strictly defined mathematically to ensure the trajectory privacy of the participating users.