Trailrunner7 quotes a report from On the Wire: Credential theft is one of the more persistent and troubling threats in security, and researchers have been trying to come up with answers to it for decades. A team at the University of Washington has developed a system that can prevent attackers from intercepting passwords and keys sent over the air by sending them through users' bodies instead. The human body is a good transmission mechanism for certain kinds of waves, and the UW researchers were looking for a way to take advantage of that fact to communicate authentication information from a user's phone directly to a target device, such as a door knob or medical device. In order to make that idea a reality, they needed to develop a system that could be in direct contact with the user's body, and could produce electromagnetic signals below 10 MHz. And to make the system usable for a mass audience, the team needed widely available hardware that could generate and transmit the signals. So the researchers settled on the fingerprint sensor on iPhones and the touchpad on Lenovo laptops, as well as a fingerprint scanner and a touchpad from Adafruit. The concept is deceptively simple: generate an electromagnetic signal from the fingerprint sensor or touchpad and transmit that through the user's body to the target device. The signal can carry a typical password or even an encryption key, the researchers said. "We show for the first time that commodity devices can be used to generate wireless data transmissions that are confined to the human body. Specifically, we show that commodity input devices such as fingerprint sensors and touchpads can be used to transmit information to only wireless receivers that are in contact with the body," the researchers, Mehrdad Hessar, Vikram Iyer, and Shyamnath Gollakota, of UW said in their paper, "Enabling On-Body Transmissions With Commodity Devices."