The Los Alamos National Lab has been using a quantum-encrypted network to communicate sensitive information for the last two and a half years, according to the latest reports. The news item is that the laboratory’s researchers have come up with a workaround for one of the biggest challenges in this field: rerouting traffic without compromising data.

Quantum encryption is more secure than mainstream technologies because the act of measuring a quantum, such a photon transmitted by a laser device connected to a network, will always change it. This poses an impossible barrier for hackers, but it also limits the functionality of quantum networks. The problem is that data can be transmitted from point A to point B, but it can’t be distributed to additional destinations thereafter.

Richard Hughes and his colleagues at Los Alamos National Labs have solved this challenge with a hub and spoke system. The hub accepts messages, converts them into bits, and then turns them back into qubits before beaming them off to their destination. This has been done before, but the way Los Alamos addressed scalability – which is another major issue for quantum networks – is truly innovative.

From the MIT Technology Review:

“As the number of links to the hub increases, it becomes increasingly difficult to handle all the possible connections that can be made between one point in the network and another. Hughes and co say they’ve solved this with their unique approach which equips each node in the network with quantum transmitters–ie lasers–but not with photon detectors which are expensive and bulky. Only the hub is capable of receiving a quantum message (although all nodes can send and receiving conventional messages in the normal way).”