Integrated Circuit Authentication Based on Resistor and Capacitor Variations of a Low Pass Filter (LoPUF)

Abstract

Because of chip fabrication outsourcing, piracy, reverse engineering, and counterfeiting are major concerns for the semiconductor industry as well as the government. To prevent these issues, Physical Unclonable Functions (PUFs) based methods have been proposed has a way to authenticate chips. PUFs extract randomness from the manufacturing variations of a device that is probabilistic in nature. PUFs are generally easy to implement, but, because of its random behavior, its response is hard to predict and model. Many existing PUF techniques such as arbiter and ring oscillator can be hard to implement inside a chip because of their large area overhead. Hence, we have proposed a novel low pass filter PUF design in this work based on the internal resistor and capacitor variations within an IC. We have simulated the setup in Cadence Virtuoso for a 45 nm technology node. The resultant output voltage of our proposed PUF will be different at the same cut-off frequency because of the manufacturing variations. Finally, the output of the low pass filter PUF is connected with an inverter to make the signal digital and after that, a digital counter is connected with the inverter to measure the pulse width that can be used for generating a unique PUF output.