云计算与安全-人员与安全PPT课件.ppt

PeopleandSecurity 1 Contents Peopleandsecurity whatistheproblem WhyusablesecurityisimportantIntroductiontousabilityprinciplesBestPracticesforUsableSecurityinDesktopSoftware 2 PeopleandSecurity theproblem Increasingnumberofattemptedandsuccessfulsecuritybreaches User employee behaviouroftenaffordsorfacilitatessecuritybreaches Mostusershaveweakpasswords orcanbeeasilytrickedintodisclosingthem 3 Symptoms HighcostofoperationalsecurityUsers SystemAdminstratorsHelpdesks DevelopersUsers knowledgeaboutsecurityisinadequate MostpeoplehavenegativeattitudetosecuritySeenasa chore that getsintheway ofrealworkpeoplewhopracticegoodsecurityareseenas paranoid 4 The WeakestLink Securityisonlyasgoodasit sweakestlink andpeoplearetheweakestlinkinthechain BruceSchneier SecretsandLies 5 Blametheusers Untilrecently securityhasnotconsideredthehumanelementandusabilityProliferationofsystemsthatneedtobesecured loadonusershasincreasedSecuritydoesnotspeakusers language e g Whitten Tygar 1999 6 FundamentalDilemma security unawareusershavespecificsecurityrequirements butusuallynosecurityexpertise DieterGollmann ComputerSecurity 7 Thewayforward DesignsecurityasasystemthatinvolvespeopleandtechnologythatwillworkinpracticethatcanbesustainedinthelongrunTakehumannatureintoaccountDesignbasedonrationalassessmentofassets risksandthreats 8 CansystemsbesecureANDusable Lowusabilitytendstomeanslowsecurity exceptinhighlycontrolled expensivesystems Generally usablesystemsresultinbettersecuritySpecificusabilityandsecurityissuesdosometimesconflictGoodanalysisofsecurityneedsanddesigningfortherealworldleadstoworkablesecuritysolutions 9 UsabilityPrimer 10 DesignFramework 11 Users TakeusercharacteristicsintoaccountPhysicalandmentalcharacteristicsGeneral applytoallhumans andspecific usergroup characteristicsExamples memory abilitytoread pushingbuttonsKeyconsiderationforlarge scaleapplications UniversalAccess 12 HumanCharacteristics Physical humanbodynotallusershaveallcharacteristics biometrics Ageing illnessetc canmakeoperationofsomedevicesdifficult e g viewkeypads pushsmallbuttons Mentalmemory perceptions attitudes beliefspeopleseektoreducecomplexity mentalworkloadMostpeople mostofthetime preferincreasedphysicaltomentalworkload 13 GoalsandTasks HumanBehaviourisessentiallygoal drivenTasksarecompletedtoachievegoalsUserinteractswithsystemtocompletetaskProductiontasksvs enablingtasksReal worldtasksvs systemtasks 14 Context Canimpactuser systeminteractionPhysicalcontextAtmosphere climate lighting noise Use onthemove isdifferentfrom atthedesk SocialcontextPrivate semi private public SocialnormsgovernuserbehaviourOrganisationalorculture e g professionalnorms 15 UsabilityandSecurity Manykeyusabilityprinciplescanbeapplied butsecurityhasspecialchallenges ActiveadversaryManystakeholders whomayhaveconflictingprioritiesBothusabilityandsecurityneedtobeconsideredatdesignstage stickingonafterwards leadstosystemsthataretoocomplexandexpensivetomaintain 16 Keyprinciplesfordesigningusablesystems Minimiseusers physicalandmentalworkload Makesystemstatusvisible providefeedbackwhenandwhatinputhasbeenreceived Beforgiving minimiseconsequencesoferrorandhelpuserstorecover 17 BestPracticesforUsableSecurityinDesktopSoftware 18 Don tlietotheuser AligningInterface InformationandAction ROADMAP SanitizingdisksandfilesSanitizingbrowserhistory 19 DeletionandSanitization Whystudydeletion Affectseverybody weallhaveprivateorsecurity criticalinformationthatneedstobedeleted Lotsoflore notalotofgoodacademicresearch 20 Today sdesktopsystemsdoanicejobon delete 1 Startwithaniconyouwanttodelete 3 Trashiconchanges 4 Right clickforempty 6 Fileisgone 5 Confirmempty 2 Dragittothetrash 21 Double clickon RecycleBin formoreinfo JustlikePGP5 0 Goodbyconventionalstandards butdoesnotencouragesecurecomputingpractices Goodfeedback Goodhelp 22 Recoveryafterconfirmation Canyougetbackafileafteryouemptythetrash Sure 23 TheParadoxof Delete Delete Filecanberecoveredwith undelete orforensicefforts TossedfilesrandomlygetshredBackupsprovideprotection Intentionallyoverwrittenfilecannotberecoveredfromdisk Specialutilitiesoverwriteslackspace Backupsdon tgetshred Unlinksfilefromdirectory Putblocksonfreelist Allowspacetoreused Overwritesfileblocks Shred Toss ThankstoClayBennettatChristianScienceMonitor 24 Sanitizationisabigproblem Remembrance study 200harddrivespurchasedmorethan1 3haddatathatbeendeletedbutcouldberecovered Hypothesis datawastherebecauseofusabilityfailures 25 Drivesinstorage 200drives 80GBimages smalldrives 26 DOSFORMATmisrepresentsitsfunctionality A formatc WARNING ALLDATAONNON REMOVABLEDISKDRIVEC WILLBELOST proceedwithFormat Y N yFormatting1 007 96M100percentcompleted WritingoutfileallocationtableComplete DataPassed isaUsabilityProblem 27 Approach 1 Distinguish Toss from Shred Followingpublicationof Remembrance Appleadded SecureEmptyTrash toMacOS10 3 SecureEmpty takesmuchlongerthanregularempty 5mininsteadof5sec 28 Butseparatingisnotenough Isthis toss or shred EmptyTrash or SecureEmptyTrash Toss Thisis Shred 29 Thedirtylifeofadiskblock Freeblockpool Allocatedblocks unlink TrashCandirectory EmptyTrash SecureEmptyTrash scrubber Notice Onceadiskblockis emptied youcan tgobackand securely emptyit 30 Alternative Redesigntheinteraction Removedfilesgoonto oldfile list Kernelgrabsfreeblocksfirst thenblocksfrom oldfiles Make shred anexplicitoperationattheinterface extendtobackupwithindividualencryptionkeysforeachfile 31 Cleanobjectreuse Freepoolofcleanblocks Allocatedblocks unlink TrashCandirectory blockallocation Scheduledshredding or Shrednow Blocksawaitingshredder Movetrashtoshredder simulation 32 BestPractices Distinguish toss from shred Don tusea swatbox toconfirmanactionthatcan tbeundone It seasiertobegforforgivenessthanaskforpermissionLetpeoplechangetheirminds PoliteSoftwareIsSelf Confident Cooper p 167 33 Whatelsedoyouclear Files canbetossedorshredded ClearHistory Erasemytracks History iscleared 34 IE ClearingHistory 1 Select InternetOptions 2 Select ClearHistory 3 Confirm no undo 35 ClearingHistory Safarimakesiteasier Givetheabilitytoremovepersonalinformationwhereitisdisplayed It sobviousbecauseyouseeit 36 Interactionpuns Oneactionmeanstwothings ClearHistory C