基于挑战-应答机制的量子密钥分发协议

基于BB84协议，利用挑战-应答机制，提出了一种量子密钥分发协议。发送方Alice和接收方Bob通过安全信道共享三个不同的Hash函数( ， 和 )，以及随机比特串 。在每次密钥分发时，Alice产生随机比特串 （挑战信息）和 （密钥），结合 和 ，基于BB84协议产生光子串 ；Alice将 和 发送给Bob，Bob接收到对应的 和光子串 ；Bob利用 ，结合 和 ，基于BB84协议对光子串 进行测量得到 。理想情况下共享密钥 。另外，Bob利用 ， ， 及 产生应答序列 ；Alice和Bob利用各自拥有的序列及 分别产生序列 和 ，并对各自的 做更新。在密钥分发过程中光子的利用率为百分百，该协议既有BB84协议类似的安全性，又有单向身份认证功能。

A quantum key distribution protocol based on challenge-response mechanism

A quantum key distribution protocol based on BB84 protocol and a challenge-response mechanism is proposed. Through a secure channel, Alice and Bob have pre-shared three different Hash functions (denoted by , and ) and a random bit string . Every time, Alice first generates two random bit strings (challenge) and (key), then prepares a photon sequence based on BB84 protocol using , , and . Alice sends and to Bob and Bob receives the corresponding and . Bob measures according to BB84 protocol and gets corresponding . In the ideal case, should be the same as . Bob uses , , and to generate (response). At last, Alice and Bob use their own sequences and to generate and respectively, then they update their own . In our protocol, the utilization rate of photons is 100. The security of the protocol is similar as that of the BB84 protocol. Furthermore, it is a one-way identification authentication protocol.