An Entanglement-Based QKD System for Scalable Robust Multi-User NetworksONLINE ONLY

After a brief introduction into the ideas behind quantum key distribution (QKD), we report on our recent work on QKD networks. We set up a QKD network of four parties, Alice, Bob, Charlie and Diana and demonstrated simultaneous quantum key exchange between any two parties of the network based on time-bin entanglement and without the need for trusted nodes. Furthermore, we were able to show that our approach is scalable as well as robust as demonstrated in a field test in collaboration with Deutsche Telekom.