Quantum key agreement protocols based on multi-particle entangled states

Multi-particle entanglement is an important physical resource in quantum information processing, and the larger the number of particles in the entangled states, the more quantum superiority it can show in quantum communication and quantum computing. This paper proposes two quantum key agreement protocols using Ω states and six-particle entangled states. Both protocols ensure that two participants can fairly establish a final key through the measurement correlation for multi-particle entangled states. Since the protocols only use Bell measurements and Z-basis measurements, they are more easily achieved using current technology. From the perspective of security analysis, the protocols can resist participant attacks and external attacks. Finally, compared with some exising quantum key agreement protocols, our protocols can achieve higher qubit efficiency.