Physical One-Way Functions

TLDR

Modern cryptographic practice relies on one‑way functions that are easy to compute but hard to invert, yet existing ones depend on unproven conjectures or have known vulnerabilities. We show that mesoscopic physics of coherent transport through a disordered medium can be used to allocate and authenticate unique identifiers by physically reducing the medium’s microstructure to a fixed‑length binary string. The authors propose an authentication protocol that exploits the vast address space inherent to physical one‑way functions, using coherent transport in a disordered medium to encode unique identifiers as fixed‑length binary strings. These physical one‑way functions are inexpensive to fabricate, prohibitively difficult to duplicate, lack compact mathematical representation, and are intrinsically tamper‑resistant.

Abstract

Modern cryptographic practice rests on the use of one-way functions, which are easy to evaluate but difficult to invert. Unfortunately, commonly used one-way functions are either based on unproven conjectures or have known vulnerabilities. We show that instead of relying on number theory, the mesoscopic physics of coherent transport through a disordered medium can be used to allocate and authenticate unique identifiers by physically reducing the medium's microstructure to a fixed-length string of binary digits. These physical one-way functions are inexpensive to fabricate, prohibitively difficult to duplicate, admit no compact mathematical representation, and are intrinsically tamper-resistant. We provide an authentication protocol based on the enormous address space that is a principal characteristic of physical one-way functions.