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.

翻译：我们展示了利用光纤波导内部结构的独特不均匀性实现用户或光纤线路远程认证的可能性。研究表明，光时域反射仪（OTDR）可用于观测数十公里距离内不可克隆的后向散射信号模式。本文解释了所检测模式的物理本质，并研究了其特征空间周期。这些模式源于标准通信光纤的折射率波动。通过实验验证，该模式属于物理不可克隆函数（PUF）的实例。我们证实了模式的唯一性与可重复性，并提出了认证协议框架。