A team of researchers from the National University of Singapore and Yonsei University have described an interesting concept : the use of time-of-flight (ToF) sensors in modern smartphones to find hidden cameras.
Time-of-flight cameras are sometimes called “depth cameras”, and it’s all about how ToF works. Such a sensor works almost like sonar, only it uses light, not sound: the sensor emits light in the infrared spectrum and records the time it takes for it to be reflected from an object. In fact, such a sensor consists of two parts – a diode and a special light-sensitive matrix and is able to determine not only the distance to objects, but also their shape.
ToF sensors have appeared in smartphones relatively recently, for example, Sony ToF laser sensors are equipped with the iPhone 12 and 13, as well as the Galaxy S20 +, where they are used to work with augmented reality and to add depth information to 2D images.
Researchers are now proposing to use such devices to find hidden cameras, and a related talk has already been presented at the ACM SenSys (Conference on Embedded Networked Sensor Systems) event.
The researchers dub this technique LAPD (Laser-Assisted Photography Detection) and is a method for detecting tiny hidden lenses by looking for unusually intense reflections in the scanned area. At the same time, experts emphasize that secret surveillance and the use of hidden cameras are already becoming a global problem.
“Tiny spy cameras deployed in places such as hotel rooms, restrooms or changing rooms pose a major threat to privacy around the world. For example, in South Korea alone, over 6,800 such cases have been reported over the past year.
Attackers have the ability to place hidden cameras anywhere, while the public, on the other hand, is defenseless. This is why we are doing this work and why we hope that the discovery of hidden cameras will become more commonplace. “
Of course, there are special devices for detecting hidden cameras and other spy electronics (for example CC308 + and K18). In addition, if you wish, you can make such a device yourself. But the researchers argue that such gadgets are difficult to use correctly. What’s more, everyone now has a smartphone in their pocket, and a dedicated app like the LAPD could be an affordable, convenient and accurate alternative.
“Based on our extensive research, the LAPD has a covert camera detection rate of 88.9% compared to using the naked eye, which only detects 46% of covert cameras,” the report says.
It is also noted that the dedicated K18 detector detects spy devices only 62.3% of cases when using the continuous method (57.7% when using the blinking method). What’s more, the LAPD boasts the lowest false positive rate (16.67%) compared to the K18 two modes (26.9% and 35.2%) and the naked eye (54.9%).
The experts promise that in the near future they will definitely publish the source code of the LAPD in the public domain.
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