Physical Layer Security in Multimode Fiber Optical Networks

TL;DR

This paper demonstrates that inverse precoding algorithms exploiting mode-dependent losses in multimode fiber networks can secure communications at the physical layer, leveraging measured transmission matrices to ensure message confidentiality against eavesdroppers.

Contribution

First investigation of physical layer security in fiber optical networks using measured transmission matrices, introducing hardware-based security techniques for multimode fiber communications.

Findings

Secure message transmission demonstrated with conventional techniques.

Mode-dependent losses create SNR advantage for legitimate receivers.

Physical layer security achieved even against powerful eavesdroppers.

Abstract

Inverse precoding algorithms in multimode fiber based communication networks are used to exploit mode dependent losses on the physical layer. This provides an asymmetry between legitimate (Bob) and unlegitimate (Eve) receiver of messages resulting in a significant SNR advantage for Bob. In combination with dynamic mode channel changes, Eve has no chance to reconstruct a sent message even in a worst case scenario in which she is almighty. This is the first time, Physical Layer Security in a fiber optical network is investigated on the basis of measured transmission matrices. These results show that messages can be sent securely with conventional communication techniques. Translating the task of securing data from software to hardware represents the potential of a scientific paradigm shift. The introduced technique is a step towards the development of cyber physical systems.