两个基于Grover•搜索算法的量子直接通信协*北京邮电人学，网络与交换国家重点实验室，信息安全中心，北京1008762中国科学院信息工程研究所，信息安全国家重点实验室，北京10093摘要：基于二粒了的Grover搜索算法的特性，提出了两个量了直接通信协议，包括一个确定性安全量子通信协议和一个量子安全肓接通信I办议。借助于二粒子西操作和单光子测量技术,发送方可以将秘密消息安全的发送给接收方。理论分析表明，这两个协议具有较高的安全性。关键词：量子密码;量子氏接通信;确定性安全量子通信;量子安全直接通信;量子搜索算法中图分类号：TP309TwoQuantumDirectCommunicationProtocolsBasedonQuantumSearchAlgorithmXUShu-Jiangi.2,CHENXiu-Boi.2,NIUXin-Xim,YANGYi-Xiam1InfonnationSecurityCenter,StateKeyLaboratoryofNetworkingandSwitchingTechnology,BeijingUniversityofPostsandTelecommunications,Beijing100876,China2StateKeyLaboratoryofInformationSecurity,(InstituteofInformationEngineering,ChineseAcademyofSciences),Beijing100093,ChinaAbstract:Basedonthepropertiesoftwo-qubitGrover'squantumsearchalgorithm,wcproposetwoquantumdirectcommunicationprotocols,includingadeterministicsecurequantumcommunicationandaquantumsecuredirectcommunicationprotocol.Secretmessagescanbedirectlysentfromthesendertothereceiverbyusingtwo-qubitunitaryoperationsandthesinglephotonmeasurement.Theoreticalanalysisshowsthatthesecurityoftheproposedprotocolscanbehighlyensured・Keywords:Quantumcryptography;Quantumdirectcommunication;Deterministicsecurequantumcommunication;Quantumsecuredirectcommunication;Quantumsearchalgorithm0IntroductionMostoftheclassicalcryptographyschemes,especiallytheasymmetricalcryptographyschemes,aredesignedbasedonthepresumeddifficultyofsomemathematicalproblems,forin・基金项Fl:TheSpecializedResearchFundfortheDoctoralProgramofHigherEducation(20100005120002).作昔简介：XuShu-Jiang(1979-),male,associateresearcher,majorresearchdirection：quantumcryptography,chaoscryptography.Correspondenceauthor：ChenXiu-Bo(1976-).female»associateprofessor•majorresearchdirection:quantumcryptography・flyover100@163.com・stance,theinfeasibilityoffactoringlargeintegersandsolvingdiscretelogarithm・However,thequantumsearchalgorithm(QSA),whichisanimportantresearchtopicinquantumcomputing,makestheinfeasibilitynotexistanymore・Asaresult,mostclassicalcryptographyschemes,whichcannotachieveunconditionalsecurity,havetherisksofbeingbroken.Quantumcryptography,whichutilizesquantummechanicaltoolsincludingquantuminformationandquantumcomputationtoaccomlishcryptographictasks,provideshopetoachieveunconditionalsecurityduetoHeisenberg'suncertaintyprinciple.In1984,BennettandBrassard[1]proposedthefirstunconditionalquantumkeydistribution(QKD)protocol,whichenablestworemotelegitimateuserstoshareasecretkeybytransmittingqubits・Becauseofitsunconditionalsecurity,QKDhasattractedlargeamountofattentionsanddevelopedrapidlyinthepast30years[2,3,4,5].FollowingtheideaofQKD,researchersusedthequantummechanicaleffectstoachieveothercryptographictaskswithunconditionalsecurity,suchasquantumsecretsharing(QSS)[6,7,&9],quantumsteganography[10,11,12,13,14],quantumdirectcommunication[15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36],andsoon.Quantumdirectcommunication,whichhastheadvantagesofhighsecurityaswellaslargecapacity,usestheprincipleofquantummechanicstotransmitsecretmessagesfromthesendertothereceiveroverthequantumchanneldirectly.Therearetwoclassesofquantumcommunicationprotocols,oneisquantu...