Unlike standard drop cables (often GJXH or GJYXFCH) which are bulky and opaque, invisible fiber optic cable is a micro-diameter optical cable designed for discreet indoor deployment. 2mm (standard network cables are 6mm or thicker). Researchers at NDSS 2026 demonstrate a covert acoustic eavesdropping attack that transforms standard FTTH telecom fiber cables into passive, undetectable listening devices invisible to RF scanners and immune to ultrasonic jammers. Security researchers from The Hong Kong Polytechnic University, The. The Hong Kong Polytechnic University study, Hiding an Ear in Plain Sight, presented at this year's NDSS, an academic conference focussed on cybersecurity, demonstrates that fiber-optic cables used to carry internet data can also pick up sound. Jack Lee Smith, a. Fiber optic cables running through your walls can be turned into hidden microphones that record every word spoken in the room.
[PDF Version]