A Dummy-Location Based Location Privacy Protection In Continuous Location-Based Service

With the rapid development of mobile network and mobile positioning technology, the Location-Based Service(LBS) has been widely used in our daily activities in recent years. However, the risk of location leakage in LBS has greatly restricted the development of LBS. If the location information submitted by user is not protected, the attacker can get this position information by illegal means, and thus initiating an inferring attack on user's personal privacy information, such as obtaining user's home address and speculating the user's identity information, etc. Therefore, research on location privacy protection methods has very important practical significance for promoting the widespread use of LBS.At present researchers have proposed a lot of methods for protecting user's location privacy information, but most of them are only suitable for single LBS request scenarios. As the application scenarios of continuous LBS requests are increasing, the existing methods for location privacy protection of continuous LBS request are relatively few and they cannot fully protect the privacy of users in a continuous LBS request through our analysis.In order to solve these problems, in this paper, the research and exploration are made on the problem of location privacy protection in continuous LBS. Considering the advantages of the dummy-location method, this paper mainly focuses on the problem that existing privacy protection method based on the dummy-location cannot satisfy the privacy protection of the continuous LBS requests. A method of location privacy protection is proposed which is based on the existing dummy-location method and makes the existing dummy-location method extend to the location privacy protection method on continuous LBS requests.Specifically, the main work of this paper includes:1.A continuous reachability checking algorithm for continuous LBS requests is proposed. By analyzing the motion pattern of the user's true trajectory and taking into account the trajectory privacy protection of the dummy location candidate set from the aspects of time-rationality, direction-similarity, discrepancy and trajectory number, the dummy trajectories cannot be distinguished from the real trajectories. So that the true trajectories cannot be identified by attacker and the algorithm meets the requirement of the user's trajectory privacy protection.2.The location privacy enhancement algorithm for single LBS request is proposed. By measuring the privacy level of each continuous dummy location candidate group which already meets the requirements of trajectory privacy protection from two aspects of individual query degree and dispersion, choosing the highest privacy level of the candidate group as the final dummy location set. The final selection of dummy location set can satisfy the demand of the location privacy protection in single LBS request and the demand of trajectory privacy protection the in continuous LBS requests.3.The effectiveness of the proposed scheme is verified by experimental simulation on location privacy protection in continuous LBS requests. The method of generating dummy location in single LBS request is used as the input instance for this paper. The experimental results show that the proposed method based on the existing false position generation method for single LBS request can make the existing dummy-location generation method effectively extend to the application of the continuous LBS requests. Furthermore, the proposed method can implement the trajectory privacy protection and get a higher location privacy level position than the original method. At the same time, this scheme has good practicability.