Before revision: Contact tracing has been a widely-discussed technique for controlling COVID-19. The traditional test-trace-isolate-support paradigm focuses on identifying people after they have been exposed to positive individuals, and isolating them to protect others. This article introduces an alternative and complementary approach, which appears to be the first to notify people before exposure happens, in the context of their interaction network, so that they can directly take actions to avoid exposure themselves, without using personally identifiable information. Our system has just become achievable with present technology : for each positive case, do not only notify their direct contacts , but inform thousands of people of how far away they are from the positive case, as measured in network-theoretic distance in their physical relationship network.
After revision: We introduce a fundamentally different paradigm for contact tracing : for each positive case, do not only notify their direct contacts , but inform thousands of people of how far away they are from the positive case, as measured in network-theoretic distance in their physical relationship network.