简介：Thisletterpresentsak-partyRSAkeysharingschemeandtherelatedalgorithmsarepresented.ItisshownthatthesharedkeycanbegeneratedinsuchacollaborativewaythattheRSAmodulusispubliclyknownbutnoneofthepartiesisabletodecrypttheencipheredmessageindividually.

简介：介绍了我国北斗卫星导航系统的建设和推广应用情况，分析了国外卫星导航增强系统的发展和运营管理经验，提出了一种基于北斗卫星导航系统的运营管理模式。基于构建国家级卫星导航应用综合服务系统，采用全国中心和多个分中心的运营设计框架，并通过互联网、移动互联网、手机短信和北斗短报文等方式，提供集导航、定位、通信和增值信息于一体的对外综合信息服务。

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：摘要互联网促进了创客空间的快速发展，形成了多种商业模式，增加了运营风险。而兴趣型创客空间是众创空间的基础，探索互联网下兴趣型创客空间的运营模式能为创新创业提供活力。文章结合国外经验和国情探索互联网下兴趣型创客空间的运营模式，在创客空间的构建要素、管理模式、资金来源和发展模式四个方面进行比较分析，得出创客空间的运营的一些基础性建议。

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：

简介：Withparametricdown-conversionsources(PDCSs),thenonorthogonaldecoystateprotocolbasedononevacuumandtwoweakdecoystatesispresented.ThedetectioneventsonBob'ssidearedividedintotwogroupsdependingonwhetherAlicegetsatriggerornot:triggeredcomponentsandnontriggeredcomponents.Thetriggeredcomponentsareusedtoestimatethefractionsanderrorratesofsingle-photonandtwo-photonpulses,andthenthefinalsecurekeyrateisdeduced.Besides,bothtriggeredandnontriggeredcomponentsareusedtodeduceamoreaccuratevalueofthekeygenerationrate.Thesimulationofthefinalkeygenerationrateovertransmissiondistanceshowsthatthefirstmethodcanobtainakeygenerationrateclosetothetheoreticallimitoftheinfinitedecoystateprotocol,whilethesecondmethodisbetter.

简介：<正>电信运营商们怎么也想不到竟一手培养出了自己的掘墓人——互联网企业正大肆搭乘运营商构建的网络蚕食其通话、短信等核心业务。与此同时,国家宣布向符合条件的民营资本企业发放虚拟运营牌照,电信运营商正受到前所未有的围剿日前,中国联通总经理陆益民表示,就用户数量而言,腾讯已成中国第二大运营商。其手机QQ、微信等业务,不仅占用了大量数据流量资源,而且还对运营商业务形成冲击。事实上,运营商的境地的确颇为尴尬。自2009年起,巨额3G投入和话费补贴的利润增长速度就已经逐年放缓了。以联通为例,其2012年前三季销售通信产品成本为337.8亿元,收入为290.0亿元,其中3G手机补贴46.4亿,销售亏损高达47.8亿元。这组数据成了陆益民一番"警醒"的最好注解。在投入巨额资金建设3G网络提高带宽的同时,运营商们的

简介：2007年互联网广告收入将超过杂志，中国网络服务市场快速稳步发展。到2009年，全球电信市场销售收入将从2004年的1.2万亿美元增长到1.8万亿美元。

简介：

简介：2004年亚太地区宽带网接入市场的收入预计将增至86亿美元。增长27%

简介：2004年中国宽带用户人数已经突破1500万，呈直线上升趋势。

简介：2004年移动新业务规模将达73．66亿。2006年中国网络市场将达93亿元。今年全球3G手机用户将达到2000万。

简介：<正>不知不觉间,我们已经进入了大数据时代。最早提出大数据时代到来的是全球知名咨询公司麦肯锡。正如麦肯锡所言,数据,已经渗透到当今每一个行业和业务职能领域,成为重要的生产因素。有人断言,未来的电商行业,必然是大数据的竞争。大数据在电商白热化的竞争中,正在发挥越来越重要的作用。这已经不是凭借低价、圈地运动就能获胜的战场,面对越来越多的竞争对手,电商掌舵人需要的是更精准的营销,更了解客户的需求、更好的处理客户关系。这一切,都离不开大数据的支撑。