背景技术
量子密码,诞生于Bennett和Brassard在1984年提出的具有前瞻性的量子密钥分配(Quantum key distribution,QKD)方法[1],利用量子力学的性质而非数学问题的计算复杂性来达到无条件安全。量子密码已经吸引了许多注意力并确立许多有趣的分支,如QKD[1-5]、量子安全直接通信(Quantum secure direct communication,QSDC)[6-13]、量子秘密共享(Quantum secret sharing,QSS)[14-18]等。
QKD致力于利用量子信号的传送在两个远距离通信者之间建立一个随机密钥序列,而QSDC聚焦于将一个秘密消息从一个通信者直接传送到另一个通信者而无需事先建立一个随机密钥序列。在2004年,为了实现来自两个通信者的秘密消息的相互交换,Zhang和Man[19-20]以及Nguyen[21]分别独立提出量子对话(Quantum dialogue,QD)这一新概念。QD极大地激发起研究者们的兴趣。然而,早期的QD方法[19-27]总存在信息泄露问题,意味着任何其他人无需发起任何主动攻击就能轻易地提取到关于两个通信者秘密消息的一些有用信息。QD的信息泄露问题是被Gao等[28]以及Tan和Cai[29]在2008年分别独立发现。随后,研究者们迅速转向研究如何解决QD的信息泄露问题。到目前为止,许多优秀的方法已经被提出来,如辅助量子态的直接传送[30-37]、Bell态的提取相关性[38]、控制非操作和辅助单光子[39]、量子纠缠态纠缠交换产生的测量相关性[40-41]、量子纠缠态纠缠交换结果集合编码[34-36]、量子加密共享[42-43]、辅助量子操作[44]以及量子纠缠态的测量相关性[45]。
在2007年,利用著名的BB84方法[1],Boyer等[46]提出首个半量子密码方法(即BKM2007方法),只允许一个通信者具备量子能力。在BKM2007方法中,接收者Bob被受限于在量子信道执行以下操作:(a)发送或不带干扰地返回量子比特;(b)用固定的正交基{|0>,|1>}测量量子比特;(c)制备(新的)量子比特处于固定的正交基{|0>,|1>}。在2009年,Boyer等[47]利用单光子构建了一个基于置乱的半量子密钥分配(Semi-quantumkeydistribution,SQKD)方法,其中接收者Bob被受限于执行(a)、(b)和(d)(利用不同延迟线)重新排序量子比特。根据文献[46-47]方法的定义,正交基{|0>,|1>}可被视为经典基并用经典记号{0,1}代替,因为它只涉及量子比特|0>和|1>而非任何量子叠加态。而且,接收者Bob被受限于执行以上(a)、(b)、(c)和(d)四种操作,可被视为经典的。显然,不同于传统量子密码要求所有通信者都具备量子能力,半量子密码允许部分通信者具备经典能力而非量子能力以致于她们不需要涉及量子叠加态的制备和测量。因此,半量子密码有利于部分通信者减轻量子态制备和测量的负担。
自从“半量子”的概念首次被Boyer等[46]提出,研究者们对它显示出极大的热情并尝试将它应用到不同的量子密码任务,如QKD、QSDC和QSS。这样,许多半量子密码方法,如SQKD方法[46-63]、半量子安全直接通信(Semi-quantum secure direct communication,SQSDC)方法[50,64]、半量子秘密共享(Semi-quantum secret sharing,SQSS)方法[65-69]、半量子隐私比较(Semi-quantum private comparison,SQPC)方法[70-71]、半量子密钥协商(Semi-quantum key agreement,SQKA)方法[72-73]、受控确定性安全半量子通信(Controlled deterministic secure semi-quantum communication,CDSSQC)方法[73]、半量子对话(Semi-quantum dialogue,SQD)方法[73]等,被设计出来。
容易发现,以上所有QD方法[19-27,30-45]要求两个通信者都具备量子能力。然而,这一要求可能是不切实际的,因为并不是两个通信者都能负担得起昂贵的量子资源和操作。如果只有一个通信者具备量子能力,那么对话能否成功进行?文献[73]利用Bell纠缠态提出的首个SQD方法给了这个问题一个肯定的回答。
基于以上分析,本发明致力于利用单光子作为量子载体提出一种不要求经典通信者具备测量能力的SQD方法,实现一个量子通信者和一个经典通信者之间的双向通信。本发明方法相比于传统无信息泄露QD方法的优势在于它只要求一个通信者具备量子能力。与现有的SQD方法相比,本发明方法的优势在于它仅采用单光子而非两光子纠缠态作为量子载体。
参考文献
[1]Bennett C H,Brassard G.Quantum cryptography:public-keydistribution and coin tossing.In:Proceedings of the IEEE InternationalConference on Computers,Systems and Signal Processing.Bangalore:IEEE Press,1984,175-179
[2]EkertA K.Quantum cryptography based on Bell's theorem.Phys RevLett,1991,67(6):661-663
[3]Bennett C H,Brassard G,Mermin N D.Quantum cryptography withoutBell theorem.Phys Rev Lett,1992,68:557-559
[4]Cabello A.Quantum key distribution in the Holevo limit.Phys RevLett,2000,85:5635
[5]Zhang C M,Song X T,Treeviriyanupab P,et al..Delayed errorverification in quantum key distribution.Chin Sci Bull,2014,59(23):2825-2828
[6]Long G L,Liu X S.Theoretically efficient high-capacity quantum-key-distribution scheme.Phys Rev A,2002,65:032302
[7]Deng F G,Long G L,Liu X S.Two-step quantum direct communicationprotocol using the Einstein-Podolsky-Rosen pair block.Phys Rev A,2003,68:042317
[8]Deng F G,Long G L.Secure direct communication with a quantum one-time pad.Phys Rev A,2004,69:052319
[9]Wang C,Deng F G,Li Y S,Liu X S,Long G L.Quantum secure directcommunication with high-dimension quantum superdense coding,Phys Rev A,2005,71:044305
[10]Chen X B,Wen Q Y,Guo F Z,Sun Y,Xu G,Zhu F C.Controlled quantumsecure direct communication with W state.Int J Quant Inform,2008,6(4):899-906.
[11]Gu B,Huang Y G,Fang X,Zhang C Y.A two-step quantum secure directcommunication protocol with hyperentanglement.Chin Phys B,2011,20(10):100309
[12]Liu D,Chen J L,Jiang W.High-capacity quantum secure directcommunication with single photons in both polarization and spatial-modedegrees of freedom.Int J Theor Phys,2012,51:2923-2929
[13]Chang Y,Xu C X,Zhang S B,et al..Controlled quantum secure directcommunication and authentication protocol based on five-particle clusterstate and quantum one-time pad.Chin Sci Bull,2014,59(21):2541-2546
[14]Hillery M,Buzek V,Berthiaume A.Quantum secret sharing.Phys Rev A,1999,59:1829-1834
[15]Karlsson A,Koashi M,Imoto N.Quantum entanglement for secretsharing and secret splitting.Phys Rev A,1999,59:162-168
[16]Xiao L,Long G L,Deng F G,Pan J W.Efficient multiparty quantum-secret-sharing schemes.Phys Rev A,2004,69:052307
[17]Hao L,Li J L,Long G L.Eavesdropping in a quantum secret sharingprotocol based on Grover algorithm and its solution.Sci China Ser G-Phys MechAstron,2010,53(3):491-495
[18]Hao L,Wang C,Long G L.Quantum secret sharing protocol with fourstate Grover algorithm and its proof-of-principle experimentaldemonstration.Opt Commun,2011,284:3639-3642
[19]Zhang Z J,Man Z X.Secure directbidirectional communicationprotocol using the Einstein-Podolsky-Rosen pairblock.2004,http://arxiv.org/pdf/quant-ph/0403215.pdf
[20]Zhang Z J,Man Z X.Secure bidirectional quantum communicationprotocol without quantum channel.2004,http://arxiv.org/pdf/quant-ph/0403217.pdf
[21]Nguyen B A.Quantum dialogue.Phys Lett A,2004,328(1):6-10
[22]Man Z X,Zhang Z J,Li Y.Quantum dialogue revisited.Chin Phys Lett,2005,22(1):22-24
[23]Man Z X,Xia Y J.Controlled bidirectional quantum directcommunication by using a GHZ state.Chin Phys Lett,2006,23(7):1680-1682
[24]Ji X,Zhang S.Secure quantum dialogue based on single-photon.ChinPhys,2006,15(7):1418-1420
[25]Man Z X,Xia Y J,Nguyen B A.Quantum secure direct communication byusing GHZ states and entanglement swapping.J Phys B-At Mol Opt Phys,2006,39(18):3855-3863
[26]Chen Y,Man Z X,Xia Y J.Quantum bidirectional secure directcommunication via entanglement swapping.Chin Phys Lett,2007,24(1):19-22[27]Yang Y G,Wen Q Y.Quasi-secure quantum dialogue using single photons.Sci ChinaSer G-Phys Mech Astron,2007,50(5):558-562
[28]Gao F,Guo F Z,Wen Q Y,Zhu F C.Revisiting the security of quantumdialogue and bidirectional quantum secure direct communication.Sci China SerG-Phys Mech Astron,2008,51(5):559-566
[29]Tan Y G,Cai Q Y.Classical correlation in quantum dialogue.Int JQuant Inform,2008,6(2):325-329
[30]Shi G F,Xi X Q,Tian X L,Yue R H.Bidirectional quantum securecommunication based on a shared private Bell state.Opt Commun,2009,282(12):2460-2463
[31]Shi G F,Xi X Q,Hu M L,Yue R H.Quantum secure dialogue by usingsingle photons.Opt Commun,2010,283(9):1984-1986
[32]Sheikhehi F,Naseri M.Probabilistic bidirectional quantum securecommunication based on a shared partially entangled states.Int J QuantInform,2011,9(Suppl.):357-365
[33]Shen D S,Ma W P,Yin X R,Li X P.Quantum dialogue withauthentication based on bell states.Int J Theor Phys,2013,52(6):1825-1835
[34]Ye T Y,Jiang L Z.Quantum dialogue without information leakagebased on the entanglement swapping between any two Bell states and the sharedsecret Bell state.Phys Scr,2014,89(1):015103
[35]Ye T Y.Large payload bidirectional quantum secure directcommunication without information leakage.Int J Quant Inform,2013,11(5):1350051
[36]Ye T Y.Robust quantum dialogue based on the entanglement swappingbetween any two logical Bell states and the shared auxiliary logical Bellstate.Quantum InfProcess,2015,14(4):1469-1486
[37]Wang H,Zhang Y Q,Liu X F,Hu Y P.Efficient quantum dialogue usingentangled states and entanglement swapping without informationleakage.Quantum InfProcess,2016,15(6):2593-2603
[38]Shi G F.Bidirectional quantum secure communication scheme basedon Bell states and auxiliaryparticles.Opt Commun,2010,283(24):5275-5278
[39]Shi G F,Tian X L.Quantum secure dialogue based on single photonsand controlled-not operations.J Mod Opt,2010,57(20):2027-2030
[40]Gao G.Two quantum dialogue protocols without informationleakage.Opt Commun,2010,283(10):2288-2293
[41]Gao G,Fang M,Wang Y,Zang D J.A Ping-Pong quantum dialogue schemeusing genuine four-particle entangled states.Int J Theor Phys,2011,50(10):3089-3095
[42]Ye T Y.Quantum secure dialogue with quantum encryption.CommunTheor Phys,2014,62(3):338-342
[43]Ye T Y.Fault tolerant channel-encrypting quantum dialogue againstcollective noise.Sci China-Phys Mech Astron,2015,58(4):040301
[44]Huang L Y,Ye T Y.A kind ofquantum dialogue protocols withoutinformation leakage assisted by auxiliary quantum operation.Int J Theor Phys,2015,54(8):2494-2504
[45]Ye T Y.Quantum dialogue without information leakage using asingle quantum entangled state.Int J Theor Phys,2014,53(11):3719-3727
[46]Boyer M,Kenigsberg D,Mor T.Quantum key distribution withclassical Bob.Phys Rev Lett,2007,99(14):140501
[47]Boyer M,Gelles R,Kenigsberg D,Mor T.Semiquantum keydistribution.Phys Rev A,2009,79(3):032341
[48]Lu H,Cai Q Y.Quantum key distribution with classical Alice.Int JQuant Inform,2008,6(6):1195-1202
[49]Zou X F,Qiu D W,Li L Z,Wu L H,Li L J.Semiquantum-key distributionusing less than four quantum states.Phys Rev A,2009,79(5):052312
[50]Sun Z W,Du R G,Long D Y.Quantum key distribution with limitedclassical Bob.Int J Quant Inform,2013,11(1):1350005
[51]Zou X F,Qiu D W,Zhang S Y,Mateus P.Semiquantum key distributionwithout invoking the classical party’s measurement capability.Quantum InfProcess,2015,14(8):2981-2996
[52]Zhang W,Qiu D W.A single-state semi-quantum key distributionprotocol and its security proof.2017,http://arxiv.org/pdf/quant-ph/161203087.pdf
[53]Krawec W O.Restricted attacks on semi-quantum key distributionprotocols.Quantum InfProcess,2014,13(11):2417-2436
[54]Krawec W O.Security ofa semi-quantum protocol where reflectionscontribute to the secret key.Quantum InfProcess,2016,15(5):2067-2090
[55]Boyer M,Mor T.Comment on“Semiquantum-key distribution using lessthan four quantum states”.Phys Rev A,2011,83(4):046301
[56]Zou X F,Qiu D W.Reply to“Comment on‘Semiquantum-key distributionusing less than four quantum states’”.Phys Rev A,2011,83(4):046302
[57]Wang J,Zhang S,Zhang Q,Tang C J.Semiquantum key distributionusing entangled states.Chin Phys Lett,2011,28(10):100301
[58]Krawec W O.Mediated semi-quantum key distribution.Phys Rev A,2015,91(3):032323
[59]Boyer M,Katz M,Liss R,Mor T.A new and feasible protocol for semi-quantum key distribution.2017,http://arxiv.org/pdf/quant-ph/170107044.pdf
[60]Tan Y G,Lu H,Cai Q Y.Comment on“Quantum key distribution withclassical Bob”.Phys Rev Lett,2009,102(9):098901
[61]Zhang X Z,Gong W G,Tan Y G,Ren Z Z,Guo X T.Quantum keydistribution series network protocol with M-classical Bobs.Chin Phys B,2009,18(6):2143-2148
[62]Krawec W O.Security proofofa semi-quantum key distributionprotocol.In:Proceedings ofthe 2015 IEEE International Symposium onInformation Theory (ISIT),Hong Kong:IEEE Press,2015,pp.686-690
[63]Zhang W,Qiu D W,Mateus P.Security ofa single-state semi-quantumkey distributionprotocol.2016,http://arxiv.org/pdf/quant-ph/161203170.pdf
[64]Zou X F,Qiu D W.Three-step semiquantum secure directcommunication protocol.Sci China-Phys Mech Astron,2014,57(9):1696-1702
[65]Li Q,Chan W H,Long D Y.Semiquantum secret sharing using entangledstates.Phys Rev A,2010,82(2):022303
[66]Wang J,Zhang S,Zhang Q,Tang C J.Semiquantum secret sharing usingtwo-particle entangled state.Int J Quant Inform,2012,10(5):1250050
[67]Li L Z,Qiu D W,Mateus P.Quantum secret sharing with classicalBobs.J Phys A:Math and Theor,2013,46(4):045304
[68]Xie C,Li L Z,Qiu D W.A novel semi-quantum secret sharing schemeof specific bits.Int J Theor Phys,2015,54(10):3819-3824
[69]Yang C W,Hwang T.Efficient key construction on semi-quantumsecret sharing protocols.Int J Quant Inform,2013,11(5):1350052
[70]Chou W H,Hwang T,Gu J.Semi-quantum private comparison protocolunder an almost-dishonest third party.arXiv:1607.07961
[71]Thapliyala K,Sharmab R D,Pathak A.Orthogonal-state-based andsemi-quantum protocols for quantum private comparison in noisyenvironment.arXiv:1608.00101
[72]Liu W J,Chen Z Y,Ji S,Wang H B,Zhang J.Multi-party semi-quantumkey agreement with delegating quantum computation.Int J Theor Phys,2017,56:3164-3174
[73]Shukla C,Thapliyal K,Pathak A.Semi-quantum communicationprotocols for key agreement,controlled secure direct communication anddialogue.arXiv:1702.07861
[74]Shannon C E.Communication theory ofsecrecy system.Bell SystemTech J,1949,28:656-715
[75]Li C Y,Zhou H Y,Wang Y,Deng F G.Secure quantum key distributionnetwork with Bell states and local unitary operations.Chin Phys Lett,2005,22(5):1049-1052
[76]Li C Y,Li X H,Deng F G,Zhou P,Liang Y J,Zhou H Y.Efficientquantum cryptography network without entanglement and quantum memory.ChinPhys Lett,2006,23(11):2896-2899
[77]ShorP W,Preskill J.Simple proofofsecurity ofthe BB84 quantum keydistribution protocol.Phys Rev Lett,2000,85(2):441
[78]Cai Q Y.Eavesdropping on the two-way quantum communicationprotocols with invisible photons.Phys Lett A,2006,351(1-2):23-25
[79]Gisin N,Ribordy G,Tittel W,Zbinden H.Quantum cryptography.Rev ModPhys,2002,74(1):145-195
[80]DengFG,ZhouP,LiXH,LiCY,ZhouHY.Robustnessoftwo-way quantumcommunication protocols against Trojan horse attack.2005,http://arxiv.org/pdf/quant-ph/0508168.pdf
[81]LiXH,DengFG,ZhouHY.Improving the security of secure directcommunication based on the secret transmitting order of particles.Phys Rev A,2006,74:054302