简介:ThisstudyconcernssecurityissuesoftheemergingWirelessBodySensorNetwork(WBSN)formedbybiomedicalsensorswornonorimplantedinthehumanbodyformobilehealthcareappli-cations.Anovelauthenticatedsymmetric-keyestablishmentschemeisproposedforWBSN,whichfullyexploitsthephysiologicalfeaturesobtainedbynetworkentitiesviathebodychannelavailableinWBSNbutnototherwirelessnetworks.Theself-definedIntrinsicSharedSecret(ISS)isusedtoreplacethepre-deploymentofsecretsamongnetworkentities,whichthuseliminatescentralizedservicesorau-thoritiesessentialinexistingprotocols,andresolvesthekeytransportprobleminthepuresymmet-ric-keycryptosystemforWBSNaswell.Thesecuritypropertiesoftheproposedschemearedemon-stratedintermsofitsattackcomplexityandthetypesofattacksitcanresist.Besides,theschemecanbeimplementedunderalight-weightwayinWBSNsystems.DuetotheimportanceoftheISSconcept,theanalysisonusingfalseacceptance/falserejectionmethodtoevaluatetheperformanceofISSforitsusageintheschemeisalsodemonstrated.
简介:Recently,ithasbeenseenthattheensembleclassifierisaneffectivewaytoenhancethepredictionperformance.However,itusuallysuffersfromtheproblemofhowtoconstructanappropriateclassifierbasedonasetofcomplexdata,forexample,thedatawithmanydimensionsorhierarchicalattributes.Thisstudyproposesamethodtoconstructeanensembleclassifierbasedonthekeyattributes.Inadditiontoitshigh-performanceonprecisionsharedbycommonensembleclassifiers,thecalculationresultsarehighlyintelligibleandthuseasyforunderstanding.Furthermore,theexperimentalresultsbasedontherealdatacollectedfromChinaMobileshowthatthekey-attributes-basedensembleclassifierhasthegoodperformanceonbothoftheclassifierconstructionandthecustomerchurnprediction.
简介:Histogramofcollineargradient-enhancedcoding(HCGEC),arobustkeypointdescriptorformulti-spectralimagematching,isproposed.TheHCGECmainlyencodesroughstructureswithinanimageandsuppressesdetailedtexturalinformation,whichisdesirableinmulti-spectralimagematching.Experimentsontwomulti-spectraldatasetsdemonstratethattheproposeddescriptorcanyieldsignificantlybetterresultsthansomestate-ofthe-artdescriptors.
简介:Timeefficiencyofkeyestablishmentandupdateisoneofthemajorproblemscontributorykeymanagementsstrivetoaddress.Toachievebettertimeefficiencyinkeyestablishment,weproposeaLocation-basedHuffman(L-Huffman)scheme.First,usersareseparatedintoseveralsmallgroupstominimizecommunicationcostwhentheyaredistributedoverlargenetworks.Second,bothuser'scomputationdifferenceandmessagetransmissiondelayaretakenintoconsiderationwhenHuffmancodingisemployedtoformingtheoptimalkeytree.Third,thecombinedweightsinHuffmantreearelocatedinahigherplaceofthekeytreetoreducethevarianceoftheaveragekeygenerationtimeandminimizethelongestkeygenerationtime.SimulationsdemonstratethatL-HuffmanhasmuchbetterperformanceinwideareanetworksandisalittlebetterinlocalareanetworkthanHuffmanscheme.
简介:Certificatelessencryptionattractsalotofattentionsofarbyeliminatingthekeyescrowprobleminidentity-basedencryptionandpublickeycertificatesinthetraditionalpublickeycryptography.Byconsideringthethreatfromthekeyexposure,itisdesirabletoincorporatetheideaofkey-insulatedcryptosystemintothecertificatelessencryption.Inthispaper,wehavedesignedanefficientcertificatelesskeyinsulatedencryption(CL-KIE)schemetoachievethisgoal.Byourapproach,thecomputationalperformanceofourschemehasbeenimprovedsignificantlyintermsofreductiononrunningtimeandstorage.WealsogavethesecurityproofofthenewCL-KIEschemeagainstthechosenplaintextattacks(CPAs)intherandomoracle,consideringtheassumptionofthecomputationalDiffie-Hellman(CDH)problem.
简介:Nowadays,thepassword-basedremoteuserauthenticationmechanismusingsmartcardisoneofthesimplestandconvenientauthenticationwaystoensuresecurecommunicationsoverthepublicnetworkenvironments.Recently,Liuetal.proposedanefficientandsecuresmartcardbasedpasswordauthenticationscheme.However,wefindthatLiuetal.’sschemeisvulnerabletotheoff-linepasswordguessingattackanduserimpersonationattack.Furthermore,italsocannotprovideuseranonymity.Inthispaper,wecryptanalyzeLiuetal.’sschemeandproposeasecurityenhanceduserauthenticationschemetoovercometheaforementionedproblems.Especially,inordertopreservetheuseranonymityandpreventtheguessingattack,weusethedynamicidentitytechnique.Theanalysisshowsthattheproposedschemeismoresecureandefficientthanotherrelatedauthenticationschemes.
简介:Withouttheassumptionthattheprivatekeysarekeptsecureperfectly,cryptographicprimitivescannotbedeployedintheinsecureenvironmentswherethekeyleakageisinevitable.Inordertoreducethedamagecausedbythekeyexposureintheidentity-based(ID-based)signaturescenariosefficiently,weproposeanID-basedkey-insulatedsignatureschemeinthispaper,whicheliminatestheexpensivebilinearpairingoperations.Comparedwiththepreviouswork,ourschememinimizesthecomputationcostwithoutanyextracost.Underthediscretelogarithm(DL)assumption,asecurityproofofourschemeintherandomoraclemodelhasalsobeengiven.
简介:Intheair-waterquantumkeydistribution(QKD),theirregularseasurfacehassomeinfluenceonthephotonpolariza-tionstate.Thewindisconsideredasthemainfactorcausingtheirregularity,sothemodelofirregularseasurfacebasedonthewindspeedisadopted.Therelationshipsofthequantumbiterrorratewiththewindspeedandtheinitialincidentanglearesimulated.Therefore,themaximumsecuretransmissiondepthofQKDisconfirmed,andthelimita-tionofthewindspeedandtheinitialincidentangleisdetermined.Thesimulationresultsshowthatwhenthewindspeedandtheinitialincidentangleincrease,theperformanceofQKDwillfalldown.Undertheintercept-resendattackcondition,themaximumsafetransmissiondepthofQKDisupto105m.Torealizesafecommunicationsinthesafedivingdepthofsubmarines(100m),theinitialincidentangleisrequestedtobenotexceeding26~,andwiththeinitialincidentan~leincreased,thelimitationofwindspeedisdecreased.
简介:Withparametricdown-conversionsources(PDCSs),thenonorthogonaldecoystateprotocolbasedononevacuumandtwoweakdecoystatesispresented.ThedetectioneventsonBob'ssidearedividedintotwogroupsdependingonwhetherAlicegetsatriggerornot:triggeredcomponentsandnontriggeredcomponents.Thetriggeredcomponentsareusedtoestimatethefractionsanderrorratesofsingle-photonandtwo-photonpulses,andthenthefinalsecurekeyrateisdeduced.Besides,bothtriggeredandnontriggeredcomponentsareusedtodeduceamoreaccuratevalueofthekeygenerationrate.Thesimulationofthefinalkeygenerationrateovertransmissiondistanceshowsthatthefirstmethodcanobtainakeygenerationrateclosetothetheoreticallimitoftheinfinitedecoystateprotocol,whilethesecondmethodisbetter.
简介:一个光标签的标签扑灭比率和分散赔偿正在交换传播系统优化,它采用40-Gb/s回来到调音的零微分阶段移动(RZ-DPSK)用622-Mb/s振幅移动调音标记的收费载重(问)控制数据。在我们的计划,收费载重和标签的接收装置敏感分别地完成-27.8dBm和-33.5dBm。在在40km上播送了以后,60km和80km挑选模式纤维(SMF)(与分散赔偿)分别地,收费载重能没有力量惩罚被恢复,当标签能与不到2dB惩罚被恢复时。
简介:目前PSWF的脉冲产生方法在硬件实现方面有着编程复杂,计算量大,资源消耗多等制约因素,因此亟需一种适合实时产生PSWF脉冲信号的方法。通过分析Walsh函数系的特点和产生原理,提出了一种基于Walsh函数系的PSWF脉冲波形重构方法。其中,Walsh系数可以通过已有的PSWF数值点与P编号的Walsh矩阵求解得出,再截取所需精度的Walsh系数参与重构PSWF脉冲波形,从而达到降低存储量的目的。由于Walsh码型中的±1与数字电路中的01有着天然对应的关系,重构时只需将Walsh系数相加减,从而降低计算量。仿真结果表明,利用Walsh函数系可以较好地重构PSWF脉冲波形,且算法简单,避免了乘法运算,降低了计算量和存储量,有利于工程实现。