How Doctor Who is this? The boffins at the National Institute of Standards and Technology have put together a prototype of a high-speed quantum key distribution (QKD) system, and they sent us a photo to prove it.
Like the TARDIS, it all looks reassuringly low tech, but is really mindbendingly sophisticated. In typical quantum crypto, the key to an encrypted message is sent from one person to another via a stream of photons of light. The beauty is that no one can copy that key, because if anyone attempts to read the data, that act of observation changes the data itself.
The NIST system shoots out photons at a wavelength compatible with existing fibre-optic telecoms networks. It then converts them to a wavelength suited to a device that can detect single photons without adding a lot of noise. The upshot? A system that generates and transmits secure keys at a rate of over half a million bits a second over 10km of optical fibre--fast enough to encrypt streaming video in real time, according to the researchers.
Physics isn't my strong point, but it all seems very cool to me. I'm sure there are lots of holes to be poked in it--aren't there always?--so if you want more details, take a look at the NIST researchers' paper here: http://w3.antd.nist.gov/quin.shtml.