An Optical-Fiber-Based Key for Remote Authentication of Users and Optical Fiber Lines

TL;DR

This paper demonstrates a novel remote authentication method using the unique, unclonable backscattered signal patterns in optical fibers, leveraging their physical inhomogeneities as a physical unclonable function (PUF).

Contribution

It introduces a new optical fiber-based authentication technique utilizing intrinsic inhomogeneities as PUFs, verified through OTDR measurements over long distances.

Findings

Backscattered patterns are unique and reproducible.

Patterns are due to refractive index fluctuations in standard fibers.

OTDR can observe these patterns at tens of kilometers.

Abstract

We have shown the opportunity to use the unique inhomogeneities of the internal structure of an optical fiber waveguide for remote authentication of users or an optic fiber line. Optical time domain reflectometry (OTDR) is demonstrated to be applicable to observing unclonable backscattered signal patterns at distances of tens of kilometers. The physical nature of the detected patterns was explained, and their characteristic spatial periods were investigated. The patterns are due to the refractive index fluctuations of a standard telecommunication fiber. We have experimentally verified that the patterns are an example of a physically unclonable function (PUF). The uniqueness and reproducibility of the patterns have been demonstrated and an outline of authentication protocol has been proposed.