基于密集编码的多用户量子密钥分发协议

MULTI-USER QUANTUM KEY DISTRIBUTION PROTOCOL BASED ON DENSE CODING

在保密通信系统中,n个用户进行密钥分发一般需要0. 5n×(n-1)个信道。为了减少信道数量,提出一种基于密集编码的多用户量子密钥分发协议,能确保n个用户只需要n个信道就可以实现用户间的密钥分发。该协议中,如果任意两个用户想要进行通信,由半可信第三方制备Bell粒子,分别发送给两个用户。根据粒子在X基和Z基的不同特性实现密钥分发,一个粒子能传输两比特的信息。进一步分析表明,半可信第三方只需要诚实地制备粒子并公布对应的测量基,但是并不能推测出正确的密钥信息。同时,该协议能够发现窃听、抵御截获重发攻击和纠缠攻击。

In the secure communication system, n users generally need 0.5 n×（n -1） channels for key distribution. In order to reduce the number of channels, this paper proposed a multi-user quantum key distribution protocol based on dense coding, which could ensure that n users only needed n channels to realize key distribution among users. In the protocol, if any two users wanted to communicate, the semi-trusted third party prepared Bell particles and sent them to two users. According to the different characteristics of the particle in the X and Z bases, the distribution of the key was realized. One particle could transmit two bits of information. Further analysis shows that the semi-trusted third party only requires the honest preparation of the particles and publishes the corresponding measurement basis, but the correct key information cannot be deduced. And the protocol can detect eavesdropping, resist and intercept retransmission attacks and entangled attacks.