Private Colocation Discovery: Taming the Coronavirus While Preserving Privacy

Successful containment of the Coronavirus pandemic rests on the ability to quickly identify those who have been in close proximity to a contagious individual. Existing tools for doing this rely on large-scale collection of personal information, with the attendant risks to individual privacy. Instead, we propose an extremely simple cellphone-based scheme for providing fine-grained, reliable and timely information to users who have been in the vicinity of an infected individual, without the need for access or central storage of any personal information (including location history). Our scheme can be simply implemented with very little infrastructure.