BodyCom – Your Body as a Secure Communication Channel


Ever run to your house in the rain while holding a brief case and a bag of groceries? That’s not a time to fumble for your keys.

Microchip Technology has recently announced a new wireless authentication technology called the BodyCom that could save you the hassle of a locked door.  Instead of digging for keys, you would unlock your door by just touching the knob.

The BodyCom is a short-range wireless communication technology that uses the human body as a communication channel to secure electronic devices and let users gain access with just a touch. The system consists of a fixed Base Unit and one or more battery powered wireless Mobile Units made in the form of key fobs. Both units are capacitively coupled with the human body. This means they will not function unless they are both in close proximity to the user’s body.

The system is activated by a user touching the Base Unit. When the Base Unit detects the touch though a coupling element, it initiates a transmission that searches for the Mobile Unit.  It uses the human body as an extension of the coupling element, allowing the transfer of the signal in the proximity of the Mobile Unit. After the transmitted signal is received by the Mobile Unit, it decodes the data and, if a response is necessary, will respond.

This technology could have many applications beyond opening doors.  Users can secure power tools, firearms and computers so that only an authorized user with the right fob could get them to work.  Or a collar-mounted fob could let a pet open a doggy door, while keeping out unwanted animals.

BodyCom promises energy efficiency through its low frequency wireless transmission (125 KHz – 8 MHz) between the Base Unit and Mobile Units. Due to the frequency ranges used, the design of the units does not involve RF antennas. This allows for simpler circuit designs. 

The company has released the technology in the form of a development kit called BodyCom Development Kit (part # DM160213).  It comes with a central controller unit and two wireless mobile units.  The Development Kit looks like an interesting way for electronics enthusiasts to design and test their own access control projects.