The progress of location-based services has led to serious concerns on location privacy leakage. For effective and efficient location privacy preservation (LPP), existing methods are still not fully competent. They are often vulnerable under the identification attack with side information, or hard to be implemented due to the high computational complexity. In this paper, we pursue the high protection efficacy and low computational complexity simultaneously. We propose a LPP method based on the paradigm of counterfeiting locations. To make fake locations extremely plausible, we forge them through synthesizing (AIs). The AIs refer to the synthesized traces which have similar semantic features to the actual traces, and do contain any target location. Two dedicated techniques are devised: the and . They play significant roles in two critical steps of synthesizing AIs. We conduct experiments on real datasets in two cities (Shanghai, China and Asturias, Spain) to validate the high efficacy and scalability of the proposed method. In these two datasets, the experimental results show that our method achieves the preservation efficacy of @math and @math , and its run time of building the generators is only @math and @math seconds, respectively. This study would give the research community new insights into improving the practicality of the state-of-the-art LPP paradigm via counterfeiting locations.
(1) Anonymizing the actual location in a set of locations of other users. This anonymization mechanism is a function to hide the user in the class with @math users in @cite_10 @cite_37 @cite_27 @cite_14 @cite_21 @cite_31 @cite_24 . @cite_31 , selected the fake traces among others with some strict constraints for a targeted real trace. Although this protection performs well, other's privacy was leaked during this process. @cite_14 divided the area into clusters (namely @math ) where each cluster includes @math users. When a client proposes a query to the LBS provider, the boundary of the area he belongs to is sent to the servers. However, this method limits an adversary's probability to infer the accurate location to @math . If there are no @math clients near the user, the @math will be too large to provide satisfactory service. Moreover, this exposes the general location of them. @cite_27 extracted the semantic features of regions by the distribution of nearby users' staying duration of locations. By the semantic features, they computed the cloaking area. However, the approach is invalid when there are not enough other users around.
@cite_37 @cite_14 @cite_21 @cite_24 @cite_27 @cite_31 @cite_10
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We present a path perturbation algorithm which can maximize users location privacy given a quality of service constraint. This work concentrates on a class of applications that continuously collect location samples from a large group of users, where just removing user identifiers from all samples is insufficient because an adversary could use trajectory information to track paths and follow users footsteps home. The key idea underlying the perturbation algorithm is to cross paths in areas where at least two users meet. This increases the chances that an adversary would confuse the paths of different users. We first formulate this privacy problem as a constrained optimization problem and then develop heuristics for an efficient privacy algorithm. Using simulations with randomized movement models we verify that the algorithm improves privacy while minimizing the perturbation of location samples. The continuous advances in sensing and positioning technologies have resulted in a dramatic increase in popularity of Location-Based Services (LBS). Nevertheless, the LBS can lead to user privacy breach due to sharing location information with potentially malicious services. A high degree of location privacy preservation for LBS is extremely required. In this paper, a clustering K-anonymity scheme for location privacy preservation (namely CK) is proposed. The CK scheme does not rely on a trusted third party to anonymize the location information of users. In CK scheme, the whole area that all the users reside is divided into clusters recursively in order to get cloaked area. The exact location information of the user is replaced by the cloaked spatial temporal boundary (STB) including K users. The user can adjust the resolution of location information with spatial or temporal constraints to meet his personalized privacy requirement. The experimental results show that CK can provide stringent privacy guarantees, strong robustness and high QoS (Quality of Service). Several models for incorporating spatial constraints into role-based access control (RBAC) have been proposed, and researchers are now focusing on the challenge of ensuring such policies are enforced correctly. However, existing approaches have a major shortcoming, as they assume the server is trustworthy and require complete disclosure of sensitive location information by the user. In this work, we propose a novel framework and a set of protocols to solve this problem. Specifically, in our scheme, a user provides a service provider with role and location tokens along with a request. The service provider consults with a role authority and a location authority to verify the tokens and evaluate the policy. However, none of the servers learn the requesting user's identity, role, or location. In this paper, we define the protocols and the policy enforcement scheme, and present a formal proof of a number of security properties. In this article, we present a new privacy-aware query processing framework, Capser*, in which mobile and stationary users can obtain snapshot and or continuous location-based services without revealing their private location information. In particular, we propose a privacy-aware query processor embedded inside a location-based database server to deal with snapshot and continuous queries based on the knowledge of the user's cloaked location rather than the exact location. Our proposed privacy-aware query processor is completely independent of how we compute the user's cloaked location. In other words, any existing location anonymization algorithms that blur the user's private location into cloaked rectilinear areas can be employed to protect the user's location privacy. We first propose a privacy-aware query processor that not only supports three new privacy-aware query types, but also achieves a trade-off between query processing cost and answer optimality. Then, to improve system scalability of processing continuous privacy-aware queries, we propose a shared execution paradigm that shares query processing among a large number of continuous queries. The proposed scalable paradigm can be tuned through two parameters to trade off between system scalability and answer optimality. Experimental results show that our query processor achieves high quality snapshot and continuous location-based services while supporting queries and or data with cloaked locations. As the use of mobile devices increases, a location-based service (LBS) becomes increasingly popular because it provides more convenient context-aware services. However, LBS introduces problematic issues for location privacy due to the nature of the service. Location privacy protection methods based on k-anonymity and l-diversity have been proposed to provide anonymized use of LBS. However, the k-anonymity and l-diversity methods still can endanger the user's privacy because location semantic information could easily be breached while using LBS. This paper presents a novel location privacy protection technique, which protects the location semantics from an adversary. In our scheme, location semantics are first learned from location data. Then, the trusted-anonymization server performs the anonymization using the location semantic information by cloaking with semantically heterogeneous locations. Thus, the location semantic information is kept secure as the cloaking is done with semantically heterogeneous locations and the true location information is not delivered to the LBS applications. This paper proposes algorithms for learning location semantics and achieving semantically secure cloaking. Due to the popularization of location based services (LBSs), preserving user's location privacy has become a significant issue. In this paper, we assume that users are traveling by car and propose a location anonymization method which mainly aims at reducing traceability of user's movement trajectory. Since the movement patterns of car-driving users have some special characteristics due to various factors such as traffic rules, generating dummies in an artificially-synthesized manner is not practical. Therefore, in our method, we use real car trace data which were obtained from probe cars to generate dummies so that the generated dummies look like real users. In doing so, our method tries to find real traces which can cross with the user or another dummy at an intersection in order to reduce the user's traceability. Through simulations, we confirm that our method can reduce the traceability of the user's trajectory compared with some naive approaches. As location-aware applications begin to track our movements in the name of convenience, how can we protect our privacy? This article introduces the mix zone-a new construction inspired by anonymous communication techniques-together with metrics for assessing user anonymity. It is based on frequently changing pseudonyms.