Fig. 1: Conceptual illustration of a multi-node quantum network.

Physical qubits are represented by nodes (circles), while edges (lines) represent pair-wise interactions that entangle the qubits within the wider network. Here, we define a network consisting of six users represented by nodes within the rounded rectangle. Within this network, four of the users may wish to perform quantum protocols such as conference key agreement. The traditional method involves distributing Bell pairs among the participants first, followed by post-processing steps to extract keys in a pairwise fashion before arriving at the final conference key as shown by the right path in blue. An alternative approach is to obtain a GHZ state and employ a multi-party quantum conference key agreement protocol to extract the key directly, as represented in the left red path.