The folks at Microchip Technology have come up with a blend of wireless and touch technologies that allows for a highly secure, bidirectional data link between a central controller and one or more wireless units. In this link, your body acts as the wiring.
Introduced today at the Embedded World conference in Germany, the BodyCom technology provides an alternative to traditional wireless proximity systems for secure communications. Microchip says its alternative uses less power, has a smaller bill of materials, and can be more secure than other short-range secure wireless communications.
In automotive keyless entry, for example, the traditional wireless system requires the automobile to generate a continual RF inductive field that seeks to stimulate a response from the wireless security token (i.e., key fob) the driver carries. Once that token is detected and authenticated, the automobile will unlock and start at the push of a button. But the automobile needs to generate a substantial RF field, and the token needs to generate an RF response. This produces significant drain for both the automobile and token batteries.
Further, the security of this approach can be defeated through a relay attack, in which one party amplifies the vehicle's signal and sends it to a second party wandering through a crowd with a relay transceiver. When the second party nears the vehicle owner, the relayed vehicle signal triggers the security token, which is relayed back to the vehicle to unlock and enable driving. In effect, the thieves have electronically picked your pocket to steal your car keys.
The BodyCom system is also wireless. However, instead of generating a substantial RF field, the system depends on a combination of capacitive and touch technologies. One unit capacitively couples a high-frequency signal to the carrier's body. When the carrier touches the other unit, a bidirectional link is established. By using the body as the linking mechanism, BodyCom can work with much lower signal power levels, and it avoids broadcasting a signal that a third party can readily intercept or spoof.
Microchip's new technology is available for implementation in any of its MCU devices, using the BodyCom Development V1.0 Framework freely downloadable from the company's website. Further, Microchip is offering a $149 BodyCom System Development Kit containing a controller and two wireless units ready for experimentation.
The BodyCom approach has applications well beyond keyless entry. Imagine, for instance, having power tools keyed so that only you could activate them. Neither your children nor a thief could pick up your circular saw and use it. Only you could use the tool -- and only when you are holding the security token.
Medical monitoring is another potential application. While I was in the hospital, the nurses had to laser-scan my ID badge barcode each time they administered medicine. This was to authenticate that I was the right recipient and to record their delivery. A BodyCom system would have allowed the same kind of interrogation simply through touch.
How might you use this technology?