In-region Location Verification Using Distance Bounding
Location-based services have grown rapidly in recent years. Determining the location of a service user, however, appears to come with two seemingly contradictory requirements: on one hand, the location information is needed to be accurate up to a certain level, and on the other hand, the user may want their location information to remain private. The first problem, determining the location of a user is challenging in untrusted settings. An untrusted user may always claim a false location to gain services from a service provider. Sometimes the user may want to claim a shorter distance, and other times a longer one, based on the requirements of the service provider. One of the prominent systems that is being used for the last two decades to validate such claims is distance bounding protocol. Distance (upper) bounding protocol is used to verify that a user (prover) is no farther than a given distance from the verifier. Distance upper bounding protocols have a number of applications, including: secure localization, secure location verification, authentication. A more recent work on distance bounding introduces the dual problem of verifying that a prover is no closer than a given distance from the verifier. The proposed protocol, which is named distance lower bounding, is applicable in scenarios where the privileges are provided to users located far away from the verifier. We propose Distance Range Bounding (DRB) as a new problem that requires a prover to show that its distance from the verifier is between two bounds: a given upper bound and a given lower bound. We provide a formal model that captures security requirements in this scenario. We design a distance range bounding protocol and prove its security with respect to our model. Our protocol is based on two secure distance bounding protocols: a distance upper bounding and a distance lower bounding protocol. We use the two protocols in a way that the new protocol preserves the security property of the original ones and has provable security in DRB model. The distance range obtained by our proposed protocol can be used in the localization algorithms. We use the protocol to design an efficient and robust in-region verification protocol, where the goal is to verify if a user is located within a bounded area/zone. An upfront requirement of location-based services is the users' desire not to reveal their exact location for privacy reasons. In-region location verification systems verify if a user is within a region. Our second contribution is the design of a privacy enhanced location verification system that uses an in-region location verification approach for a given policy area, and verifies whether a location claim is from within the area. The novelty of our work is to use distance range bounding to construct a pseudo-rectangle (P-rectangle) that provides the best coverage for the area, and verify the location claim with respect to the P-rectangle. We define the error in verification decision, and show that it can be reduced by subdividing the area and using multiple rectangles to cover it. We analyze the privacy of the system against an adversary who monitors the radio communication, and use it to infer the location of the prover, and provide methods of protecting against this attack. We discuss our results and propose directions for future research.
Akand, M. M. (2016). In-region Location Verification Using Distance Bounding (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26547