Design of Delayed PUF Circuit Based on Dynamic Subthreshold

Physical unclonable function (PUF) circuits can effectively resist intrusive physical attacks. However, with the continuous improvement of chip integration and IoT (Internet of Things) technology, model attacks and limited energy budgets not only seriously threaten the security of PUF circuits, but also limit the energy efficiency of PUF circuits. By the study of PUF circuit and subthreshold logic, this paper proposes a design scheme of delay PUF circuit based on dynamic subthreshold. Firstly, a sub-threshold voltage control circuit is utilized to form the nonlinear part of the output function. And then, the initial value of the output voltage is modified by charge sharing effect to form a nonlinear output function that varies with the excitation signal. Finally, the PUF response is outputted by a dynamic subthreshold arbiter. The proposed PUF circuit is designed in TSMC 65 nm CMOS technology and verified by HSPICE tool. Experimental results show that the circuit can effectively resist model attacks and has an energy consumption of 0.23pJ/bit which is 20.67% lower than similar circuits.