A team at the University of Washington has demonstrated the ability to use sensors on commodity devices such as smartphones and laptops to generate wireless data transmissions that are confined to the human body.
Currently, smart devices use radio (including Bluetooth and WiFi) to communicate. These waves are inherently open to tapping. The researchers have instead designed and tested a system to send information in the form of low-frequency, electromagnetic (EM) signals. These signals degrade in the air, but travel well on the human body. Transmitting and receiving devices (similar to fingerprint sensors and touchpads) must be in contact with the body for the communication to be successful.