网络异常流检测技术研究

《网络异常流检测技术研究》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、VlⅢ764分类号UDC编号：04110614舻幽建喾博士学位论文网络异常流检测技术研究学位申请人导师4：t名厦职称陆伟古书顺争教授通信与信息系统ABSTRACTInrecentyears，denial-of-service(DOS)attackpresentsmostseriousthreatstothestabilityoftheInternet．DoSattackgeneratesalargevolumeoftrafficloadstoexhaustnetworkresourcesandpreventlegitimateusersfr

2、omaccessinganInteractservice．Nowadays，newstrategieshavebeenappliedtoDoSattacksinordertoescapedetection．Attackmachinescalldecreasetheirattackratestomimiclegitimateusersorsendhighnarrowspikestolaunchapulsingbaseddenialofserviceattack．However，mostcurrentresearchesCalldetectth

3、eoccurrenceofDoSattack,butfailtoexplicitlydistinguishlegitimateusersandattackmachines．TllispaperpresentsahiddenMarkovmodel(}玎Ⅷ旧basedmethodtodistinguishlegitimatetrafficandattacktraffic．111emethodfirstusesalargenumberoflegitimatelaserrequestsequencestotrainanHMMandthenusest

4、hismodeltocheckeachincomingrequestsequences．Incomingtrafewhosesequence’Slikelihoodfallsintounreasonablerangeswouldbeclassifiedaspotentialattackmachineandshouldbecontrolled．WefurtheruseanHMM—basedclusteringmethodtoclusterthelegitimateusers’accesspattemsandgetadedicatedmodel

5、foreachcluster．TllispaperalsopresentsallHSMM(HiddenSemi-MarkovModel)baseddetectionmethodtodetectpulsingbaseddenialofserviceattack．nlemethodCannotonlydetectaggregativestreamcontainingattackflowsbutalsoidentifytheattackflows．111emethodUSeSCBF(CountingBloomFilter)torecordthet

6、ra：陆contheboUlenecklink,andHSMMtoidentifytheexistenceofpulsingbaseddenialofserviceattack．Iftheattackexists，themethodlocatesandfilterstheattackflowbasedonthetra伍crecord．Finally,inconsideringthatanDoSattackmaycausethedegradeofnetworkperformance，wepresentanewschemetomeasurean

7、destimatepacketlossrate，one-wayqueuingdelayanddelayjitterofthenetworkperformancemetrics，whichisvalidatedindiffiemtscenarios．Keywords：Anomalydetection,HiddenMarkovModel，DenialofserviceattackIV本人郑重声明：原创性声明所呈交的学位论文，是本人在导师的指导下，独立进行研究工作所取得的成果。除文中已经注明引用的内容外，本论文不包含任何其他个人或集体已经发表或撰

8、写过的作品成果。对本文的研究作出重要贡献的个人和集体，均已在文中以明确方式标明。本人完全意识到本声明的法律结果由本人承担。学位论文作者签名：日期：7o明砗f2月3日学位论文使用授