Experimental analysis of variability in WS$_2$-based devices for hardware security

TL;DR

This paper experimentally investigates the variability of WS$_2$-based devices, assessing their potential for hardware security applications by analyzing their conductivity variability across different conditions.

Contribution

It provides the first detailed experimental characterization of WS$_2$ devices' variability, highlighting their suitability for security primitives.

Findings

Significant variability in device conductivity observed.

Conductivity shows consistent dependence on bias and temperature.

WS$_2$ devices can generate randomness for security use.

Abstract

This work investigates the variability of tungsten disulfide (WS$_2$)-based devices by experimental characterization in view of possible application in the field of hardware security. To this aim, a preliminary analysis was performed by measurements across voltages and temperatures on a set of seven Si/SiO$_2$/WS$_2$ back-gated devices, also considering the effect of different stabilization conditions on their conductivity. Obtained results show appreciable variability in the conductivity, while also revealing similar dependence on bias and temperature across tested devices. Overall, our analysis demonstrates that WS$_2$-based devices can be potentially exploited to ensure adequate randomness and robustness against environmental variations and then used as building blocks for hardware security primitives.