Quantum cryptography is supposed to be a kind of holy grail solution for securing the smart grid, cloud computing, and other sensitive networked resources. The technology is still experimental, with only a handful of companies globally providing quantum key distribution services. Now, researchers at Los Alamos National Lab have quietly revealed that they’ve successfully been running what amounts to a mini quantum internet for the past two-and-a-half years.
The basic premise of keeping information secret using quantum mechanical phenomena lies in what is popularly called the observer effect. A quantum message, sent as photons, will be permanently altered if someone observes it, so the sender and recipient will be able to tell if there was a breach. What this means currently is that only one-to-one quantum secured communications are possible over a single optical fiber. Routing the message onward is problematic, again because of the observer effect: reading the sending instructions in the message alters the message itself.
To get around this issue, the Los Alamos scientists developed a hub-and-spoke architecture for their quantum network. The nodes on the network’s spokes can talk to each other via the hub, and quantum security is maintained by messages being converted to conventional bits at the hub, before again being reconverted to quantum bits for further transmission.
This system is not yet a perfect “pure” quantum internet because its security is only as good as that of the hub, and true node-to-node quantum communications aren’t yet possible. However, the extremely short latencies and the scalability of the system are a significant advance for quantum networked communications. The researchers highlighted some possible applications for the system, including cryptography for the smart grid, where optical fiber is already widely deployed, and as a “retrofit” solution to existing communication infrastructures. Plug-and-play crypto-modules are already in the works, and could be coming to your TV or computer in the not-so-distant future.
The researchers explain their setup in this video.