Multiparty Quantum Key Agreement Protocol with Entanglement Swapping

Secure and fair multiparty quantum key agreement protocols demand all participants influence and negotiate the shared secret key with equal right and nobody can determine the shared secret key only by himself. To ensure the security and high efficiency, a novel multiparty quantum key agreement protocol based on entanglement swapping between Bell states and G-like states is proposed. This protocol makes full use of Bell states and G-like states as quantum resources and utilizes Bell measurement, Z-basis measurement and unitary operations to generate the shared secret key. It demonstrates that this proposed multiparty quantum key agreement protocol is secure and fair, and simpler with higher efficiency than some other protocols, especially when the number of participants in the protocol is big enough. Furthermore, the proposed protocol can be implemented with existing physical technologies.