Low-complexity energy-efficient security approach for e-health applications based on physically unclonable functions of sensors

We propose an e-health sensor security scheme using a physically unclonable function (PUF) of the sensor. As a proof-of-concept, we present the approach in the context of silicon photodiodes and use their dark current variations as the desired PUF. The challenge to authenticate the system is generated by quadratic residues. We show that using such a design provides a two-fold security measure in both analog and digital domains. We use measured, simulated and analyzed results of currents, adversary attacks, and energy requirements to validate the approach. This concept can be extended to e-health applications that use other types of sensors (beyond photodiodes) as long as the sensor exhibits random-like physical property variations.