Researchers at The University of Washington’s Networks and Mobile Systems Lab are experimenting with technology that sends signals such as passcodes through the skin. Touchpads and fingerprint readers create the signals that are then transmitted through the body. Unlike wireless broadcasts, these electrical transmissions cannot be intercepted in the air.
The science requires an individual to touch a transmitter, such as a fingerprint reader on an iPhone, when they are within distance or in contact with a receiver. That touch then initiates a signal or electromagnetic pulse that is detected by the end device after transmission just below the skin of the individual or conduit. TechInsider gives the example of a door knob that can be opened only by the person with the paired signaling device, such as a smartphone or a wearable.
The same technology could be applied in the health sectors for calorie counting or for dispensing insulin by pumps. The technology is dependent on faint electromagnetic signals that devices emit when used normally. According to Vikram Iyer, one of two lead authors on a paper about the technology, some devices like fingerprint readers and track pads give off very reliable signals, and the researchers tested the use of these devices as transmitters.
For fingerprint scanners, rapid activation and deactivation creates patterns in the power. For the improvised transmitters, the transfer rate was not great and reached 50 bits per second. That is slow but sufficient to send a four-digit code in well under a second. With customer hardware, speeds could be markedly faster. According to the researchers, the IBM Thinkpad showed the fastest transfer rate and the fingerprint reader with the iPhone 6S had the most powerful signal.
Iyer said, “Our focus here was trying to find a way we could reuse an existing device … One of the main problems with adopting this kind of technology into a commercial application is that there’s already so much included in a phone. Any device manufacturer wouldn’t add another radio, because that would take up power, or space that they could use to make the battery a little bigger.”
The researchers also claim that there is no additional health hazard because the electromagnetic noise is already being produced by the device. Security too is a benefit of this type of technology because there is no airborne signal for a hacker to intercept. That would require, for example, “malware on a smartwatch that could be used to eavesdrop on a passcode as it moves from limb to limb,” and Iyer does not consider this a likely scenario.