KAIST researchers develop $7 SweepLED hidden camera detector

Researchers at KAIST, in collaboration with the National University of Singapore and Singapore Management University, have developed SweepLED, a low-cost tool designed to detect hidden cameras. The device uses an attachable LED case that costs less than $7 to manufacture, turning a standard smartphone into a specialized detector.

Unlike traditional handheld detectors that rely on simple light reflections—which can be easily confused with shiny surfaces like metal or plastic—SweepLED utilizes a unique method. It keeps the smartphone camera stationary while sweeping LED light from multiple directions. This process captures specific light deformations caused by the internal structure of a camera lens, such as the aperture and sensor.

An AI model then analyzes the recorded light sweep to identify these characteristic deformations. In laboratory testing against 30 common objects found in hotels or rentals, the system achieved approximately 94% accuracy, identifying potential cameras in under five seconds per object.