Physical Unclonable Function (PUF) device based on single stage voltage amplifiers for secure signature generation in the Internet of Things

Abstract

Wireless sensor networks based on the Internet of Things (IoT) paradigm are of paramount importance to collect and share large amount of data in different fields of application. At the same time, cyberattacks represent a serious threat for the security of IoT systems and countermeasures have been proposed to mitigate the risks of cyberattacks in IoT systems.

Physical Unclonable Functions (PUF) are devices that exploit the random variations of the device parameters introduced during the manufacturing process to generate a secret key that can be considered virtually unclonable. PUF devices can be used, for instance, to generate a secure signature for device authentication or cryptographic algorithms.

In this paper, we present a PUF device that is based on the uncertainties due to transistors’ manufacturing parameters present in a single stage voltage amplifier. We present two different PUF implementations, one implemented by using bipolar junction transistors (BJTs) and the other implemented by using metal oxide semiconductor (MOS) transistors. We compare their performance by means of experimental measurements. The experimental results have shown that the best performance is achieved by the PUF based on BJT transistors, which features acceptable values of uniqueness (44.98 %), and uniformity (52.40 %), with very high values of steadiness and reliability to temperature and power supply fluctuations (all above 99.40 %). Instead, the PUF based on MOS transistors presents a lower steadiness and reliability than the PUF based on BJTs, but it can generate responses with higher number of bits, thus increasing security.