基于Bell测量与三粒子纠缠态的量子密钥协商协议

Quantum Key Agreement Protocol Based on Bell Measurement and Three-particle Entanglement

受控非门(Controlled NOT,CNOT)攻击可利用纠缠比特间的相关性来窃听共享密钥。受这一攻击方式的启发,文章针对量子密钥协商(QKA)中可能面临的安全与效率问题,提出了一个基于Bell测量与三粒子纠缠态的量子密钥协商协议。该协议利用受控非门将Bell纠缠态及一个单量子比特转换成三粒子纠缠态,并通过幺正操作及Bell测量,实现Alice与Bob间的密钥协商。理论分析表明,该协议是安全且有效的,其效率为40%,其安全性表现在他既可以抵抗外部窃听者的攻击,也可以抵抗内部参与者的攻击。与HSUEH[1]等人的协议和申冬苏[2]等人的协议相比,协议的两个参与者均不能事先单独决定共享密钥,且双方对共享密钥的贡献相同。

The controlled non-gate attack can use the correlation between the quantum entangledbits to eavesdrop the shared secret key.Inspired by this kind of attacks,this paper proposed a quantumkey agreement protocol based on Bell measurement and three particle-entangled states for the securityand effi ciency problems that may be faced in quantum key agreement(QKA).This protocol applies aControlled-NOT gate to convert the Bellen tangled bits and a single bit into a three-particle entangledstate,and negotiate the quantum key agreement between Alice and Bob with unitary operations andBell measurements.The theoretical analysis shows,the protocol whose quantum efficiency is40%is safe and effi cient,and its security is manifested as that it can resist both the external eavesdropperattacks and the internal attacks.Compared with the protocol of Hsueh[1]and Shen[2],either side of thetwo sides in the protocol cannot separately determine the shared secret key in advance,and the twoparticipants have the same contribution to the shared secret key.