A hybrid dynamic n-party quantum key exchange protocol based on three-particle GHZ states

Combined with the quantum key agreement (QKA) and quantum key distribution (QKD) technology, a hybrid dynamic N-party quantum key exchange (QKE) protocol based on three-particle GHZ states is proposed. Using the election algorithm, three initial participants are selected, and the three initial participants perform QKA in combination with the GHZ state and decide on the final exchanged key. Each initial participant implements QKD with the remaining two participants, and eventually, all participants receive the exchanged key. The proposed protocol uses the GHZ state and Pauli operation to construct a new type of coding to realize the concurrent key protocol between multiple QKD nodes and has feasible time complexity.