TV-PUF : A Fast Lightweight Analog Physically Unclonable Function

Abstract

Physical Unclonable Function (PUF) is hardware analog of a one-way function which can address hardware security issues such as device authentication, generating secret keys, producing seeds for Random Number Generators, etc. Traditional silicon PUFs are based on delay (Ring Oscillator PUFs and Arbiter PUFs) or memory structures (like SRAM). In this paper, we propose a novel idea of a very fast, lightweight and robust analog PUF that exploits the susceptibility of Threshold Voltage (${V_{th}}$) of MOSFETs to process variations. We call this the Threshold Voltage PUF (TV-PUF). Extensive implementations and simulations shows improvement in quality metrics like uniformity of the PUF, intra-die distances (reliability metric of the PUF) and inter-die distances (uniqueness metric of the PUF) for 64-bit key generation. For 1 GHz clock input for sense amplifier, our design consumes 0.18$\mu$W/bit power with 50 \% uniqueness and 51\% reliability. It is also shown that TV-PUF characteristics are independent on the technology node