Eavesdropping attack that turns optical fiber into a “microphone”: Chinese researchers reveal a method that abuses it as a vibration sensor to overhear conversations: Innovative Tech

Researchers from Hong Kong Polytechnic University and The Chinese University of Hong Kong demonstrated a side-channel attack that turns fiber-optic cables into makeshift microphones.

By winding the cable around a cylinder and combining distributed acoustic sensing with AI, they could recover speech and identify everyday sounds from a distance.

The finding shows that even “safe” optical links can leak audio information depending on installation conditions, creating a new threat to FTTH and telecom infrastructure.

The work is slated for NDSS 2026 and raises fresh concerns about the security of fiber-based communications.