  This work is inspired by the outbreak of COVID-19, and some of the challenges
we have observed with gathering data about the disease. To this end, we aim to
help collect data about citizens and the disease without risking the privacy of
individuals. Specifically, we focus on how to determine the density of the
population across the country, how to trace contact between citizens, how to
determine the location of infections, and how to determine the timeline of the
spread of the disease. Our proposed methods are privacy-preserving and rely on
an app to be voluntarily installed on citizens' smartphones. Thus, any
individual can choose not to participate. However, the accurateness of the
methods relies on the participation of a large percentage of the population.

Cryptography and Security