Researchers at the University of Washington have developed a system for sending secure signals through the human body.

Why would you want to do that? WiFi and Bluetooth, the standard ways in which we send signals over short distances, can both be hacked. However, by using the human body rather than air as a medium of transmission, that danger is reduced if not removed.

Fingerprint sensors, like those used with the iPhone, send out low-frequency signals that are used to read fingerprints. The team at UW figured out how to use those signals to send out information. As an example, a person could hold their thumb on a smart door handle, then hold their thumb on the phone to send data through the body to the handle. This is the example they used to test the idea, and so far it’s been a success.

“Fingerprint sensors have so far been used as an input device,” says senior author Shyam Gollakota, an assistant professor of computer science and engineering at UW. “What is cool is that we’ve shown for the first time that fingerprint sensors can be re-purposed to send out information that is confined to the body.”

Co-lead author Vikram Iyer, a UW electrical engineering doctoral student, says, “We showed that it works in different postures like standing, sitting, and sleeping. We can also get a strong signal throughout your body. The receivers can be anywhere [on the body] and still work.”

The technology also has potential use for wearable devices and, more importantly, personal medical devices like glucose meters. The benefit for medical devices is that they can verify the patient’s identity before they send information to a database or medical professional.

The team wants to do further research in this area in order to develop better systems, but for that they would need a deeper access to fingerprint sensor software. The manufacturers of that technology would probably be willing to participate, given that advancing this research would also help them improve their own products and develop new ones.