Optical PUFs as physical root of trust for blockchain-driven applications

In an environment where cyber attacks are increasing, both in frequency and complexity, novel ways to shield data, users, and procedures have to be envisioned. Physical unclonable functions (PUFs) are the physical equivalent of one-way mathematical transformations with the exception that their inherent physical complexity renders them resilient to cloning. One interesting deployment scenario includes PUFs as random key generators. The deterministic nature of their operation alleviates the necessity to store the keys in non-volatile means. Along the same lines, blockchain is inherently resistant to modification of the data once stored while their overall security depends on the quality and secrecy of users' keys. Here, the authors propose a novel optical PUF implementation that can be combined with private blockchain modalities in order to cyber-harden Internet of things ecosystems. PUF-related experimental results are presented, alongside implementation scenarios.