Physical unclonable function (PUF) security devices based
on hardware
are becoming an effective strategy to overcome the dependency of the
internet cloud and software-based hacking vulnerabilities. On the
other hand, existing Si-based artificial security devices have several
issues, including the absence of a method for multiple key generation,
complex and expensive fabrication processes, and easy prediction compared
to devices retaining natural randomness. Herein, to generate unique
and unpredictable multiple security keys, this paper proposes novel
PUF devices consisting of a disordered random mixture of two self-assembled
monolayers (SAMs) formed onto p-type Si. The proposed PUF devices
exhibited multikeys at different voltage biasing, including 0 V, through
the arbitrary dipole effect. As a result, multiple unpredictable hardware
security keys were generated from one device using a simple solution-coating
process. The PUF security device based on the mixture of materials
with different dipoles developed in this study can provide valuable
insights for implementing various PUF devices in the future.