Fiber Networks as Unintended Microphone Arrays: Attack Surface, Vulnerability, and Defenses

Research Project, 2025 – 2030

Fiber-optic networks, the backbone of modern communication, may unintentionally function as large-scale microphone arrays due to their sensitivity to acoustic vibrations. This project investigates the cybersecurity risks of passive acoustic eavesdropping, where adversaries could extract speech or activity patterns from modulated optical signals. Unlike active methods that inject probe signals, passive monitoring exploits existing communication signals, making acoustic side-channel extraction more challenging but potentially enabling scalable, covert surveillance. The research systematically examines this novel threat across three key areas: (1) analyzing attack feasibility and adversarial capabilities, (2) developing advanced signal processing and machine learning techniques for acoustic information extraction, and (3) designing countermeasures to mitigate these risks while maintaining network performance. Combining theoretical analysis with experimental validation, this interdisciplinary project establishes the first rigorous security assessment of passive fiber-based acoustic vulnerabilities, providing foundational insights into an emerging cybersecurity threat.