Stefan Mileschin

Researchers at Los Alamos National Labs have been running a quantum internet for the last two and a half years, according to Technology Review.

It has been a holy grail of security experts to create a quantum internet that allows perfectly secure communication based on quantum mechanics.

The big idea is that if you measure a quantum object, such as a photon, it is always changed. In a quantum internet any attempt to eavesdrop on a quantum message will leave telltale signs of snooping.

This means that anybody can send a "one-time pad" over a quantum network which can then be used for secure communication using normal email. The user is sure that the cryptography key is secure and not been tampered with. Since it is only used once, there is no change of a hacker knowing what the key is, unless they are a cat which is potentially dead and alive at the same time. Fortunately these are quite rare.

Some forms of quantum networking have been around for a while, but they are limited by the fact that they can only be point-to-point connections over a single length of fibre.

This means that they can only send secure messages directly and cannot be routed.

What Richard Hughes and his mates at Los Alamos National Labs in New Mexico have revealed is that they have been running an alternative quantum internet for two and half years.

This uses a quantum network based around a hub and spoke-type network. All messages get routed from any point in the network to another via this central hub.

So as long as the hub is secure, then the network should also be secure.

While this idea has been thought of, it has been difficult to scale, Los Alamos got around this problem by equipping each node with quantum transmitters. Only the hub is capable of receiving a quantum message but all nodes can send and receiving conventional messages in the normal way.

This means that the entire network is secure, and scalable provided that the central hub is not attacked.

Los Alamos has already designed and built plug-and-play type modules that are about the size of a box of matches so that it will not cripple any network.

The big idea is to eventually have a modules built in to almost any device connected to a fibre optic network, such as set top TV boxes, home computers and so on, to allow perfectly secure messaging.

http://news.techeye.net/science/los-...antum-internet