KAIST’s SweepLED detects hidden cameras with about 94% accuracy By Luís Henrique Costa
2 min read
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A smartphone accessory that costs less than US$ 7 in parts can now spot hidden cameras in under five seconds per object, according to researchers at the Korea Advanced Institute of Science and Technology (KAIST). The device, called SweepLED, is an LED array that attaches to the back of a phone, and it runs on an artificial intelligence system. KAIST announced the project on August 30, 2026, and the research team, led by Professor Han Jun of the School of Computing, worked with the National University of Singapore (NUS) and the Singapore Management University (SMU).
Current ways to find hidden cameras depend on flashlights or on the infrared sensor built into some smartphones. These methods usually require a long manual search, and they sometimes miss tiny lenses. They also produce many false alarms, because shiny objects can look like a lens. KAIST said hidden cameras are increasingly placed in hotels, short-term rentals and restrooms, which created the need for a tool that ordinary users can operate.
The LED grid is built from low-cost diodes and is attached to the smartphone. The phone camera stays still while the LEDs light the object from different directions, so ordinary reflections shift or disappear. A camera lens, whether visible or hidden, has an internal optical structure that creates a distinct reflection pattern, and the AI was trained to recognize that pattern. In tests on 30 objects, some with disguised cameras, KAIST reported about 94% detection accuracy, a clear step up from manual inspection.
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Hidden cameras in private places such as bathrooms, fitting rooms and hotel rooms have become a growing concern in many parts of the world, especially in East Asia. Women protested over the issue in South Korea in 2018. SweepLED does not protect against the more than 40,000 security cameras that send data without encryption around the world, and it does not cover smart glasses that record images without consent. The United States Air Force has banned the use of certain devices at its bases, which adds to the privacy debate. The device is still a research prototype and is not sold to consumers yet, and KAIST says the team plans to make the hardware smaller and improve real-time analysis.
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