Artificial fingerprints engraved through block-copolymers as nanoscale physical unclonable functions for authentication and identification

Abstract

Besides causing financial losses and damage to the brand's reputation, counterfeiting can threaten the health system and global security. In this context, physical unclonable functions (PUFs) have been proposed to overcome limitations of current anti-counterfeiting technologies. Here, we report on artificial fingerprints that can be directly engraved on a wide range of substrates through self-assembled block-copolymer templating for secure authentication and identification. We show that engraved nanopatterns are unclonable unique objects that endow high encoding capacity density while satisfying main requirements of PUFs, including high aging and thermal stability. Besides showing that these nanopatterns can be encoded in binary code matrices with high entropy and high uniqueness, we propose a strategy for robust authentication and identification in real-world scenarios based on computer vision concepts. These results can shed new light on the realization of PUFs embracing the inherent stochasticity of self-assembled materials at the nanoscale.