Quantum conference key agreement with photonic graph states

Future quantum networks will provide multi-node entanglement enabling secure quantum communication on a global scale. Traditional two-party quantum key distribution (2QKD) consumes pairwise entanglement which is costly in constrained networks. Quantum conference key agreement (QCKA) leverages multipartite entanglement within networks to directly produce identical keys among N users, providing up to N-1 rate advantage over 2QKD. In this contribution I will present work on the implementation of QCKA using photonic GHZ states distributed over telecom fibre of up to 50 km combined length. Furthermore, we implemented QCKA on a constrained network consisting of a 6-qubit photonic graph state on which we apply network coding routines to demonstrate the multi-partite advantage over the two-party paradigm.