The ability to use quantum keys to encrypt communications has matured sufficiently to be used in the real world. However, to date, such quantum key distribution has been limited to communication between just two parties. In this week’s issue, Sören Wengerowsky and his colleagues demonstrate a fully connected quantum network architecture in which one source of entangled photons distributes quantum states to four different users and allows each of them to generate a secret key for secure communication. The researchers say the network will readily scale to accommodate a much larger number of users because no adaptations of the entanglement source are required to add participants. In addition, the network operates in the telecom band and does not require active switching elements, which means it could function at high quantum communication speeds.