  Contact tracing promises to help fight the spread of Covid-19 via an early
detection of possible contagion events. To this end, most existing solutions
share the following architecture: smartphones continuously broadcast random
beacons that are intercepted by nearby devices and stored into their local
contact logs. In this paper, we propose an IoT-enabled architecture for contact
tracing that relaxes the smartphone-centric assumption, and provide a solution
that enjoys the following features: (i) it reduces the overhead on the end-user
to the bare minimum -- the mobile device only broadcasts its beacons; (ii) it
provides the user with a degree of privacy not achieved by competing solutions
-- even in the most privacy adverse scenario, the solution provides
k-anonymity; and, (iii) it is flexible: the same architecture can be configured
to support several models -- ranging from the fully decentralized to the fully
centralized ones -- and the system parameters can be tuned to support the
tracing of several social interaction models. We also highlight open issues and
discuss a number of future research directions.
