为了提高量子密钥分配的安全性和效率,利用量子纠缠交换的规律, 提出了基于纠缠交换的量子密钥分配协议。 通信双方通过简单的Bell测量建立起共享密钥,窃听者不可能窃取密钥而不被发现。该协议与其它分配协议的不同在于, 可以实现对任意两个Bell态进行Bell测量达到量子密钥分配的目的。协议的实现只需要EPR粒子对,而不需要制备多粒子纠缠态。 分析结果表明,此协议只用到两粒子的纠缠态,不需要进行幺正操作,它不仅能够保证密钥分配的安全性,而且简单高效。

In order to improve the security and efficiency of quantum key distribution protocol, a protocol was proposed based on entanglement swapping. The two parties of communication establish the key by performing the Bell state measurement. No other people can get the key without being found. Different from the proposed protocol, the Bell measurement of any two Bell states can be realized to achieve the purpose of quantum key distribution. It does not need multi-particle entangled state but only EPR pair to realize the protocol. Analysis results showed that this protocol not only ensures the security of the quantum key shared information, but also uses the entanglement states of two photons without unitary operation. And the protocol is simple and efficient.