Japanese company Nippon Telegraph and Telephone Corporation (NTT) claims to have developed the first viable Human Area Network (HAN) device, enabling fast data transfer between devices using the human body as a conduit.
NTT reckons this latest advance on the wireless Personal Area Network concept - dubbed RedTacton - can transmit data over the surface of the skin at up to 2Mbps. Where it differs, though, from previous offerings, is that a RedTacton-enabled device does not have to be in direct contact with the skin - only within about 20cm. NTT explains the technical background:
Instead of relying on electromagnetic waves or light waves to carry data, RedTacton uses weak electric fields on the surface of the body as a transmission medium. A RedTacton transmitter couples with extremely weak electric fields on the surface of the body. The weak electric fields pass through the body to a RedTacton receiver, where the weak electric fields affects the optical properties of an electro-optic crystal. The extent to which the optical properties are changed is detected by laser light which is then converted to an electrical signal by a detector circuit.
RedTacton can also "transmit" through clothing or shoes, allowing the useful possibility of downloading MP3s through a floor-based sensor while dancing the Lambada. What's more, you can swap files by straight human contact, so two filesharers equipped with RadTacton devices can indulge in torrid illegal P2P activity and have sex at the same time.
But apart from that, why bother with RedTacton when Bluetooth can already do the job wirelessly? Well, Tom Zimmerman - who invented a similarish via-the-skin data system for IBM in 1996 - told the Guardian: "With Bluetooth, it is difficult to rein in the signal and restrict it to the device you are trying to connect to. You usually want to communicate with one particular thing, but in a busy place there could be hundreds of Bluetooth devices within range."
Furthermore, humans apparently make poor aerials, something which is "good for security because even if you encrypt data it is still possible that it could be decoded, but if you can't pick it up it can't be cracked," as Zimmerman explains.
Fair enough. NTT says it is committed to "moving RedTacton out of the laboratory and into commercial production as quickly as possible by organizing joint field trials with partners outside the company". There's more technical info available here.
Microsoft last year patented a system for "transmitting power and data using the human body". It's based on the IBM concept, but MS sees the technology being used primarily for power, rather than data transfers.