In the quest to build networks that can carry information reliably and with absolute security over long distances, scientists are now a big step closer, according to research in this week’s issue of Nature.

Stephan Ritter and his colleagues at the Max Planck Institute of Quantum Optics, in Garching, Germany, have constructed an elementary quantum network with two nodes. They say it is a proof of concept that could one day be extended to create large-scale quantum information networks that guarantee the security of message transmission by encoding data using the quantum state of photons.