title: Reliable location-based services from radio navigation systems.
abstract: Loran is a radio-based navigation system originally designed for naval applications. We show that Loran-C's high-power and high repeatable accuracy are fantastic for security applications. First, we show how to derive a precise location tag--with a sensitivity of about 20 meters--that is difficult to project to an exact location. A device can use our location tag to block or allow certain actions, without knowing its precise location. To ensure that our tag is reproducible we make use of fuzzy extractors, a mechanism originally designed for biometric authentication. We build a fuzzy extractor specifically designed for radio-type errors and give experimental evidence to show its effectiveness. Second, we show that our location tag is difficult to predict from a distance. For example, an observer cannot predict the location tag inside a guarded data center from a few hundreds of meters away. As an application, consider a location-aware disk drive that will only work inside the data center. An attacker who steals the device and is capable of spoofing Loran-C signals, still cannot make the device work since he does not know what location tag to spoof. We provide experimental data supporting our unpredictability claim.
authors.affiliation: Aeronautics & Astronautics Department, Stanford University, Durand Building, Stanford, CA 94305, USA. qiudi@stanford.edu
authors.forename: Di
authors.initials: D
authors.lastname: Qiu
authors.forename: Dan
authors.initials: D
authors.lastname: Boneh
authors.forename: Sherman
authors.initials: S
authors.lastname: Lo
authors.forename: Per
authors.initials: P
authors.lastname: Enge
mesh_terms: D040421:Cell Phone / Q000295:instrumentation; D005161:Facility Regulation and Control; D040362:Geographic Information Systems / Q000295:instrumentation*; D006801:Humans; D008962:Models, Theoretical; D011846:Radio Waves; D015203:Reproducibility of Results; D012637:Security Measures; D012767:Ships / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation