[0002] Yao A C[1]首次在百万富翁问题中介绍的安全多方计算(Secure Multi-party Computation,SMPC),是经典密码学中一个基本且重要的话题。在Yao A C的百万富翁问题中,两个百万富翁在不将财产的真实数量泄露给彼此的前提下希望知道谁更富裕。然后,Boudot F等[2]构建了一个相等性比较方法来判断两个百万富翁是否同等富裕。SMPC能被应用于许多场合,比如隐秘招标和拍卖、无记名投票选举、电子商务、数据挖掘等。
[0003] 作为一种特殊的SMPC,经典隐私比较(Classical Private Comparison,CPC)的目标在于判决不同双方的秘密是否相等而不泄露它们的真实值。随着量子技术的发展,CPC已经被推广到量子领域从而产生量子隐私比较(Quantum Private Comparison,QPC),后者的安全性是基于量子力学原理而非计算复杂性。然而,Lo H K[3]指出,在双方情形下,相等性函数无法被安全地衡量。这种情形就需要一些额外的假设,比如一个第三方(Third Party,TP)。
[0004] 第一个QPC方法是被Yang Y G等[4]通过利用Einstein-Podolsky-Rosen(EPR)对和一个TP的帮助设计出来。这个方法的安全性是基于单向哈希函数。具体地讲,在两个用户的秘密被单向哈希函数加密后,它们通过局域酉操作被编码进EPR对。同年,基于单光子的QPC方法被Yang Y G等[5]设计出来。在这个方法中,在两个用户的秘密被单向哈希函数加密后,它们通过酉操作被编码进单光子。在2010年,基于Greenberger-Horne-Zeilinger(GHZ)态的QPC方法被Chen X B等[6]设计出来,其中两个用户的秘密被通过对原始GHZ态的粒子进行单粒子测量产生的一次一密密钥加密。在这个方法中,TP需要执行酉操作。在2012年,一个新颖的基于ERP对的QPC方法被Tseng H Y等[7]构建出来,其中用于加密两个用户的秘密的一次一密密钥产生于对原始EPR对的粒子进行单粒子测量。幸运地是,这个方法既不需要酉操作又不需要单向哈希函数。在2012年,基于Bell态纠缠交换的QPC方法被Liu W等[8]提出,其中用于加密两个用户的秘密的一次一密密钥是通过对原始Bell态纠缠交换后产生的Bell态进行Bell基测量得到。而且,这个方法不需要酉操作。然而,Liu W J等[9]指出在文献[8]的方法中,TP能通过发起Bell基测量攻击提取出两个用户的秘密而不被检测到,并提出一个改进方法以弥补这个漏洞。目前为止,除了以上提到的方法外,许多其他双方QPC方法[10-34]也已经通过利用不同的量子态和量子技术被设计出来。
[0005] 关于TP的角色,Chen X B等[6]首先引入半忠诚模型。也就是说,TP忠诚地执行整个过程,记录所有的中间计算数据但会在不能被敌手包括不忠诚的用户腐蚀的约束下尝试从记录中得到用户们的秘密。然而,Yang Y G等[12]指出这种半忠诚TP模型是不合理的,并认为合理的模型应该如下所示:TP不能被敌手包括不忠诚的用户腐蚀但被允许按照自己的想法做出不当行为。事实上,目前为止,TP的这种假设是最合理的。
[0006] 假设存在K方,每个人都有一个秘密。她们想知道她们的K个秘密是否相等而不被泄露。如果两方QPC方法被用于解决这个多方相等性比较问题,同样的两方QPC方法不得不被执行(n-1)n(n-1)/2次以致于效率不够高。在2013年,Chang Y J等[35]利用n粒子GHZ类态提出第一个多方量子隐私比较(Multi-party Quantum Private Comparison,MQPC)方法,只要被执行一次就能实现K个用户中任意两方秘密的相等性比较。随后,基于d维基态和量子傅里叶变换的MQPC方法[36]、基于n级纠缠态和量子傅里叶变换的MQPC方法[37]被设计出来。然而,直到现在,只有很少几个MQPC方法存在。
[0007] 基于以上分析,本发明提出一种基于Bell态纠缠交换的多方量子隐私比较方法,利用Bell态的纠缠交换实现K个不同用户秘密的相等性比较。该方法只要被执行一次就能实现K个用户中任意两方秘密的相等性比较。第三方能知道每两个用户秘密的比较结果但无法知道它们的真实值。每个用户无法知道其他K-1个用户的秘密的真实值。
[0008] 参考文献
[0009] [1]Yao,A.C.:Protocols for secure computations.In:Proceedings of the 23rdAnnual IEEE Symposium on Foundations of Computer Science,p.160,IEEE Computer Society,Washington,1982
[0010] [2]Boudot,F.,Schoenmakers,B.,Traore,J.:A fair and efficient solution to the socialist millionaires’problem.Discret Appl.Math.,2001,111(1-2):23-36.[0011] [3]Lo,H.K.:Insecurity of quantum secure computations.Phys.Rev.A,1997,56(2):1154-1162
[0012] [4]Yang,Y.G.,Wen,Q.Y.:An efficient two-party quantum private comparison protocol with decoy photons and two-photon entanglement.J.Phys.A:Math.Theor,2009,42:055305;Yang,Y.G.,Wen,Q.Y.:Corriigendum:An efficient two-party quantum private comparison protocol with decoy photons and two-photon entanglement.J.Phys.A:Math.Theor,2010,43:209801
[0013] [5]Yang,Y.G.,Tian,J,W.,Hong,Y.,Zhang,H.:Secure quantum private comparison.Phys.Scr,2009,80:065002;Yang,Y.G.,Cao,W.F.,Wen,Q.Y.:Corriigendum:Secure quantum private comparison.Phys.Scr,2009,80:065002
[0014] [6]Chen,X.B.,Xu,G.,Niu,X.X.,Wen,Q.Y.,Yang,Y.X.:An efficient protocol for the private comparison of equal information based on the triplet entangled state and single-particle measurement.Opt.Commun,2010,283:1561-1565[0015] [7]Tseng,H.Y.,Lin,J.,Hwang,T.:New quantum private comparison protocol using EPR pairs.Quantum Inf.Process,2012,11:373-384
[0016] [8]Liu,W.,Wang,Y.B.,Cui,W.:Quantum private comparison protocol based on Bell entangled states.Commun.Theor.Phys,2012,57:583-588
[0017] [9]Liu,W.J.,Liu,C.,Chen,H.W.,Li,Z.Q.,Liu,Z.H.:Cryptanalysis and improvement of quantum private comparison protocol based on Bell entangled states.Commun.Theor.Phys,2014,62:210
[0018] [10]Lin,J.,Tseng,H.Y.,Hwang,T.:Intercept-resend attacks on Chen et al.′s quantum private comparison protocol and the improvements.Opt.Commun,2011,284:2412-2414
[0019] [11]Wang,C.,Xu,G.,Yang,Y.X.:Cryptanalysis and improvements for the quantum private comparison protocol using EPR pairs.Int.J.Quantum Inf,2013,11:1350039
[0020] [12]Yang,Y.G.,Xia,J.,Jia,X.,Zhang,H.:Comment on quantum private comparison protocols with a semi-honest third party.Quantum Inf.Process,2013,12:877-885
[0021] [13]Zhang,W.W.,Zhang,K.J.:Cryptanalysis and improvement of the quantum private comparison protocol with semi-honest third party.Quantum Inf.Process,2013,12:1981-1990
[0022] [14]Liu,W.,Wang,Y.B.,Jiang,Z.T.:An efficient protocol for the quantum private comparison of equality with W state.Opt.Commun,2011,284:3160[0023] [15]Li,Y.B.,Wen,Q.Y.,Gao,F.,Jia,H.Y.,Sun,Y.:Information leak in Liu et al.’s quantum private comparison and a new protocol.Eur.Phys.J.D,2012,66:110
[0024] [16]Liu,W.,Wang,Y.B.:Quantum private comparison based on GHZ entangled states.Int.J.Theor.Phys,2012,51:3596-3604
[0025] [17]Yang,Y.G.,Xia,J.,Jia,X.,Shi,L.,Zhang,H.:New Quantum private comparison protocol without entanglement.Int.J.Quantum Inf,2012,10:1250065[0026] [18]Liu,W.,Wang,Y.B.,Jiang,Z.T.:A protocol for the quantum private comparison of equality withχ-type state.Int.J.Theor.Phys,2012,51:69-77[0027] [19]Liu,W.,Wang,Y.B.,Jiang,Z.T.,Cao,Y.Z.,Cui,W.:New quantum private comparison protocol usingχ-type state.Int.J.Theor.Phys,2012,51:1953-1960[0028] [20]Jia,H.Y.,Wen,Q.Y.,Li,Y.B.,Gao,F.:Quantum private comparison using genuine four-particle entangled states.Int.J.Theor.Phys,2012,51:1187-1194[0029] [21]Xu,G.A.,Chen,X.B.,Wei,Z.H.,Li,M.J.,Yang,Y.X.:An efficient protocol for the quantum private comparison of equality with a four-qubit cluster state.Int.J.Quantum Inf,2012,10:1250045
[0030] [22]Lin,S.,Guo,G.D.,Liu,X.F.:Quantum private comparison of equality withχ-type entangled states.Int.J.Theor.Phys,2013,52:4185-4194
[0031] [23]Sun,Z.W.,Long,D.Y.:Quantum private comparison protocol based on cluster states.Int.J.Theor.Phys,2013,52:212-218
[0032] [24]Zi,W.,Guo,F.Z.,Luo,Y.,Cao,S.H.,Wen,Q.Y.:Quantum private comparison protocol with the random rotation.Int.J.Theor.Phys,2013,52:3212-3219
[0033] [25]Liu,B.,Gao,F.,Jia,H.Y.,Huang,W.,Zhang,W.W.,Wen,Q.Y.:Efficient quantum private comparison employing single photons and collective detection.Quantum Inf.Process,2013,12:887-897
[0034] [26]Lin,J.,Yang,C.W.,Hwang,T.:Quantum private comparison of equality protocol without a third party.Quantum Inf.Process,2014,13:239-247[0035] [27]Chen,Y.T.,Hwang,T.:Comment on the“Quantum private comparison protocol based on Bell entangled states”.Int.J.Theor.Phys,2014,53:837-840[0036] [28]Li,J.,Zhou,H.F.,Jia,L.,Zhang,T.T.:An efficient protocol for the private comparison of equal information based on four-particle entangled W state and Bell entangled states swapping.Int.J.Theor.Phys,2014,53:2167-2176[0037] [29]Li,Y.,Ma,Y.,Xu,S.,Huang,W.,Zhang,Y.:Quantum private comparison based on phase encoding of single photons.Int.J.Theor.Phys,2014,53:3191-3200[0038] [30]Liu,W.J.,Liu,C.,Chen,H.W.,Liu,Z.H.,Yuan,M.X.,Lu,J.S.:Improvement on“an efficient protocol for the quantum private comparison of equality with W state”.Int.J.Quantum Inf,2014,12:1450001
[0039] [31]Liu,W.J.,Liu,C.,Wang,H.B.,Liu,J.F.,Wang,F.,Yuan,X.M.:Secure quantum private comparison of equality based on asymmetric W State.Int.J.Theor.Phys,2014,53:1804-1813
[0040] [32]Zhang,W.W.,Li,D.,Li,Y.B.:Quantum private comparison protocol with W states.Int.J.Theor.Phys,2014,53:1723-1729
[0041] [33]Sun,Z.W.,Yu,J.P.,Wang,P.,Xu,L.L.,Wu,C.H.:Quantum private comparison with a malicious third party.Quantum Inf.Process,2015,14:2125-2133[0042] [34]He,G.P.:Comment on“Quantum private comparison of equality protocol without a third party”.Quantum Inf.Process,2015,14:2301-2305[0043] [35]Chang,Y.J.,Tsai,C.W.,Hwang,T.:Multi-user private comparison protocol using GHZ class states.Quantum Inf.Process,2013,12:1077-1088[0044] [36]Liu,W.,Wang,Y.B.,Wang,X.M.:Multi-party quantum private comparison protocol using d-dimensional basis states without entanglement swapping.Int.J.Theor.Phys,2014,53:1085-1091
[0045] [37]Wang,Q.L.,Sun,H.X.,Huang,W.:Multi-party quantum private comparison protocol with n-level entangled states.Quantum Inf.Process,2014,13:2375-2389
[0046] [38]Li,C.Y.,Zhou,H.Y.,Wang,Y.,Deng,F.G.:Secure quantum key distribution network with Bell states and local unitary operations.Chin.Phys.Lett.,2005,22(5):1049-1052
[0047] [39]Li,C.Y.,Li,X.H.,Deng,F.G.,Zhou,P.,Liang,Y.J.,Zhou,H.Y.:Efficient quantum cryptography network without entanglement and quantum memory.Chin.Phys.Lett.,2006,23(11):2896-2899
[0048] [40]Shi,G.F.,Xi,X.Q.,Tian,X.L.,Yue,R.H.:Bidirectional quantum secure communication based on a shared private Bell state.Opt.Commun.,2009,282(12):2460-2463
[0049] [41]Shi,G.F.:Bidirectional quantum secure communication scheme based on Bell states and auxiliary particles.Opt.Commun.,2010,283(24):5275-5278[0050] [42]Gao,G.:Two quantum dialogue protocols without information leakage.Opt.Commun.,2010,283(10):2288-2293
[0051] [43]Ye,T.Y.,Jiang,L.Z.:Improvement of controlled bidirectional quantum secure direct communication by using a GHZ state.Chin.Phys.Lett.,2013,30(4):040305
[0052] [44]Gao,F,Qin,S.J.,Wen,Q.Y.,Zhu,F.C.:A simple participant attack on the Bradler-Dusek protocol.Quantum Inf.Comput.,2007,7:329-334