基于Cluster态的可验证多方量子密钥协商方案

基于四量子比特Cluster态，提出一种可验证多方量子密钥协商方案.方案允许每次由两个参与者利用自己的子密钥分别在每个四量子比特Cluster态的两个粒子上执行X运算，并对转换后的Cluster态执行延迟测量，这保证了每个参与者对协商密钥的贡献相等.提出的方案使用相互无偏基粒子作为诱饵粒子，并且利用对称二元多项式的一对函数值对这些诱饵粒子执行酉运算，不仅可以进行窃听检验，而且还能进行参与者之间的身份验证.本方案适用于任意大于2的参与者人数.安全性分析表明，提出的方案能够抵抗外部攻击及参与者攻击.与现有的多方密钥协商方案相比，该方案不仅在诱饵粒子的使用上有优势，同时具有较高的量子比特效率.

Verifiable Multi-party Quantum Key Agreement with Cluster State

This study proposes a verifiable multi-party quantum key agreement protocol which based on X operation and four-qubit cluster states. The protocol allows two participants to perform X operations on two particles of each four-qubit cluster states using their own key at a time, and to perform delay measurements on the converted cluster state, which ensures that each participant contributes equally to the agreement key. The proposed protocol uses mutually unbiased bases particles as decoy particles and performs unitary operations on these decoy particles using a pair of function values of symmetric binary polynomial, which can not only perform eavesdropping checks, but also achieved the identity authentication between participants. The scheme can be applied to any situation with more than 2 participants. The security analysis shows that the proposed protocol can resist external attacks and participant attacks. Compared with the existing multi-party QKA, the proposed protocol not only has advantages in the use of decoy particles, but also has high quantum bit efficiency.