A Secure Centralized Multi-Party Quantum Key Distribution Protocol with New Encoding Mode

We propose a secure centralized multi-party quantum key distribution protocol based on four-particle GHZ state. Unlike centralized group session key generated by the third party, this paper uses an election algorithm to select initial participants, and the initial participants generate fairer centralized group session key, reducing dependence on the third party. Using the quantum resource GHZ state combined with unitary operations, a new encoding mode is used to quickly realize multi-party quantum key distribution, and the proposed protocol has lower time complexity. Theoretically, multi-particle GHZ state can be scaled for faster multi-party quantum key distribution. In addition, analysis and comparison show that the proposed protocol can resist common attacks and has feasible efficiency.