中文摘要：

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（H1,H2和H3）,以及随机比特串SO^AB。在每次密钥分发时,Alice产生随机比特串Sr^A（挑战信息）和Sk^A（密钥）,结合H1和SO^AB,基于BB84协议产生光子串Sp^A;Alice将Sr^A和Sp^A发送给Bob,Bob接收到对应的Sr^B和光子串Sp^B;Bob利用Sr^B,结合H1和SO^AB,基于BB84协议对光子串Sp^B进行测量得到Sk^B。理想情况下共享密钥Sr^A=Sr^B。另外,Bob利用Sr^B,Sk^B,SO^AB及H2产生应答序列S2^B;Alice和Bob利用各自拥有的序列及H3分别产生序列SO^A和SO^B,并对各自的SO^AB做更新。在密钥分发过程中光子的利用率为100%,该协议既有BB84协议类似的安全性,又有单向身份认证功能。

英文摘要：

A quantum key distribution protocol based on BB84 protocol and a challenge-response mechanism was proposed.Through a secure channel,Alice and Bob have pre-shared three different Hash functions（denoted by H1,H2 and H3） and a random bit string SO^AB.Every time,Alice first generates two random bit strings Sr^A（challenge） and Sk^A（key）,then prepares a photon sequence Sp^A based on BB84 protocol using Sr^B,Sk^B,SO^AB and H1.Alice sends Sr^A and Sp^A to Bob and Bob receives the corresponding Sr^B and Sp^B.Bob measures Sp^B according to BB84 protocol and gets corresponding Sk^B.In the ideal case,Sk^A should be the same as Sk^B.Bob uses Sr^B,Sk^B,SO^AB and H2 to generate S2^B（response）.At last,Alice and Bob use their own sequences and H3 to generate SO^A and SO^B respectively,then they update their own SO^AB.In the proposed 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.