Fiber Optic Cables Turned Into Hidden Microphones to Secretly Spy on Your Conversations

NDSS 2026 research shows ordinary FTTH fiber can be turned into a passive, RF‑silent microphone by winding fiber around a custom PET cylinder (a “sensory receptor”) and monitoring phase shifts with commercial Distributed Acoustic Sensing (DAS). The attack, requiring physical access to the ONU/ODN (e.g., by a rogue technician), achieved low word error rates and reliable sound/event detection across tens of meters, resisted ultrasonic jammers, and is difficult to detect with standard TSCM; mitigations include polished connectors, optical isolators, minimizing slack, and sound‑proofing.