Dynamic Adaptive Multi‐Party Quantum Key Agreement Based on Entanglement Swapping

Dynamic quantum networks often suffer from high resource consumption, complex implementation, and limited adaptability. To address these issues, this paper proposes two adaptive multi‐party quantum key agreement (MQKA) protocols based on entanglement swapping using three‐ and four‐particle GHZ‐like states. The protocols do not require pre‐shared keys or extra quantum operations. Participants exchange only one quantum sequence and perform Z ‐basis and Bell measurements to establish a shared key. The proposed schemes support dynamic network topologies, where participants can join or leave the network while maintaining forward security. Compared with existing MQKA protocols, they reduce quantum resource usage, communication rounds, and channel overhead. At the same time, they ensure fair key contribution and resistance to collusion and external attacks. The feasibility of these protocols is validated via experiments conducted on Qiskit and real IBM quantum hardware.