Researchers from SMU’s (Southern Methodist University) Darwin Deason Institute for Cyber-security have found that the sound waves produced when we type on a computer keyboard can be picked up by a smartphone and a skilled hacker could decipher which keys were struck.
The research was carried out to test whether the ‘always-on’ sensors in devices such as smartphones could be used to eavesdrop on people who use laptops in public places (if the phones were on the same table as the laptop) e.g. coffee shops and libraries, and whether there was a way to successfully decipher what was being typed from just the acoustic signals.
The experiment took place in a simulated noisy Conference Room at SMU where the researchers arranged several people, talking to each other and taking notes on a laptop. As many as eight mobile phones were placed on the same table as the laptops or computers, anywhere from three inches to several feet away. The study participants were not given scripts of what to say when talking, could use shorthand or full sentences when typing and could either correct typewritten errors or leave them.
Eric C. Larson, one of the two lead authors and an assistant professor in SMU Lyle School’s Department of Computer Science reported that the researchers were able to pick up what people were typing at an amazing 41 per cent word accuracy rate and that that this could probably be extended above 41 per cent if what researchers figured out what the top 10 words might be.
Sensors In Smart Phones
The researchers highlighted the fact that there are several sensors in smartphones that are used for orientation and although some require permission to be switched on, some are always on. It was the sensors that were always switched on that the researchers were able to develop a specialised app for which could process the sensor output and, therefore, predict the key that was pressed by a typist.
What Does This Mean For Your Business?
Most of us may be aware of the dangers of using public Wi-Fi and how to take precautions such as using a VPN. It is much less well-known, however, that smartphones have sensors that are always on and could potentially be used (with a special app) to eavesdrop.
Mobile device manufacturers may want to take note of this research and how their products may need to be modified to prevent this kind of hack.
Also, users of laptops may wish to consider the benefits of using a password manager for auto-filling instead of typing in passwords and potentially giving those passwords away.