2018 IEEE International Conference on Pervasive Computing and Communications, PerCom 2018
Doi
Abstract
Proximity beacons provide simple, low-cost location data. However,
beacon deployments remain rare. In this paper we introduce Bellrock, a
framework that repurposes static personal devices (phones, laptops,
etc.) as proximity beacons without revealing the location of the
device owners, and provides conventional beacons with access
control. This is done by using mutable pseudo-anonymous identifiers
that can be unmasked by a cloud service.
We develop Bellrock as a general framework, describing the repurposing
scheme and the anonymisation techniques, before applying it to
Bluetooth Low Energy beacons. We implement and demonstrate the
scalability of the de-anonymisation server, which uses a series of
heuristics. We implement a Bellrock client on Android and demonstrate
negligible impact on battery lifetime. We evaluate Bellrock using
extensive real-world office worker movements. We find that Bellrock
was able to provide proximity locations for 8,542 of the 21,796 failed
locations that would have occurred without it. We further find that
office workers were in range of one or more of their co-workers over
90\% of the time, indicating Bellrock can provide relative proximity
information even in the absence of a conventional beacon
deployment. Overall, we find that Bellrock is both feasible and
practical, providing a beacon deployment where there was none, or
supplementing existing deployments