Location privacy issues in the OpenSky network crowdsourcing platform

OpenSky Network leverages the freely accessible data generated by the aircraft through the Automatic Dependent Surveillance - Broadcast (ADS-B) technology to create a participatory global open-access network where individuals, industries, and academia can freely contribute and obtain data. Indeed, avionic data are acquired through on-ground general purpose antennas, installed and operated in adequate locations, and later delivered to the OpenSky Network community. To maintain operators’ privacy while still keeping data value, OpenSky Network promises not to reveal the antenna location, if the data contributor wishes so. Thus, open data provided to the participating entities contain neither the location of the operating receiver, nor other location identification data. In this work, we practically demonstrate that maintaining full location privacy in this scenario is almost unfeasible. We apply a time-based location estimation technique that, leveraging: (i) the disclosed location of legitimate receivers that did not opt in for location privacy; and, (ii) data provided by commercial and military aircraft, reveals with reasonable accuracy the location of the receivers that did opt-in for location privacy. Results achieved by simulations and an experimental campaign over real data provided by the OpenSky Network support our claim, further confirming that maintaining location privacy while still contributing to the community cannot be fully achieved in the actual setting, hence calling for further research.