from weak online reputation metrics to standardized … weak online reputation metrics to...

ITUWorkshopon“FutureTrustandKnowledgeInfrastructure”,Phase2

Geneva,Switzerland1July2016

Fromweakonlinereputationmetricstostandardizedattack-resistanttrustmetrics

Dr.Jean-MarcSeigneurPresidentatRéputaction SAS,ChiefReputationOfficeratGLOBCOINSeniorLecturerandResearchManageratMedi@LAB,CUIISS,G3S,

UniversityofGenevaJean-MarcSeigneur@reputaction.com

Agenda• Introduction• Today’sWeakOnlineReputationMetrics• ComputationalTrustEngines• TowardsStandardizedAttack-ResistantTrustMetrics

• Conclusion• Q&A

Onlinereputationeconomy

• By2026,thankstoonlineratings– “amoresuccessfulhospitalityandleisuresectorhasthe

potentialtoaddanextra£2bntotheUKeconomywiththeimpactonthesector’slargesupplychaincontributingafurther£1.2bn.”[Barclays,2016]

Mainonlinee-reputation ratingsservices forthegeneral public

• Especiallyinthetourismindustry– Around60%ofthehotelratingsby2providersonly[TCIResearchFrench,2015]• Booking,whoseratingsareverifiedbecausebasedafterpaymenthasbeenmade,takingaround25%ofthenightcost

• TripAdvisor,whoseratingsarenotverified

• Somehow:eBay,Yelp,Klout,TrustPilot,TrustYou,FacebookReviews,GoogleReviews…

RatingsforGoogleSEO

Amajorpitfall:trustinonlineratingsdecreases

• RepresentativesurveysofFrenchpeople– [Testntrust,2013]

• 89%trustonlineratingsin2010• 76%trustonlineratingsin2013

– [NielsenInstitute,2013]• 71%trustonlineratingsin2007• 51%trustonlineratingsin2013

Issuesofonlinereputationmetrics• eBay

– firsttoproposeanonline reputationsolution in1995– easierbecause

• centralized• focusedononecontextonly:onlineauctions• withrealmoneytransactionstraces

– Issues• same pointsforsuccessfully selling aFerrarioraUSBkey• changein2008:sellers cannot ratebuyers inorder to increase negative ratingsofsellers

• aggressivemarketing(Naymz/Visible.me spam,Reputation.comoveralarmingemails)

• resellingofprivatedatawithoutuserconsent(Rapleaf 1.0/Trustfuse)• difficultandincompletecollection,verificationandmanagementofratings• TripAdvisor

– Guiltyof falseratingsorsuccessfullyattacked• UK,2009:suedby2000hotelsassociation,changeofslogan“reviewsyoucantrust”to

“reviewsfromourcommunity”• France,2011:non-partnerhotelslistedasfullybookedevenifstillavailable inreal• Italy,2014and2015:

– feeof500kEurosbytheItaliananti-trustbodyduetounclearexplanationregardingthevalidityoftheirratings

– ghostrestaurantrankedasbestrestaurantofatouristiccity• Tunisia,2016:traveler's choiceawardgiventothehotelinTunisiawherean

Islamistterroristattackleft30Britishholidaymakersdeadlastsummer

e-Reputationratingsmainaspects

• Ratingsverifiedornot• Closedoropenalgorithmsinordertoevaluatetheirattack-

resistancebytheresearchcommunity– securitybyobscurityisbelievedtobelesssecurebythe

researchcommunity• Open,restrictedornoAPItoaccess/managethem• Theirvisualizationordigitalrepresentation

– Quantitativeonly• Scaleofstarsbetween1to5…

– Qualitativeaswell• Needofautomatedlanguagesentiment analysis

Howtovisualizetrusteffectively?

• Trustvisualizationhasarealbusinessimpact:+8%pricepremium[Johnston,1996]

TrustPlus• 2006to2012,decentralized,closedalgorithm,notverifiedratings,interestingtrustvisualization

• Scorebetween0and100• Startedin2008– focusingone-reputationinfluence– boughtforaround100millions$in2014– closedalgorithm– basedondetectedevidencesuchasnumberoffollowers/fansandtheirownscoreengagementofposts

– knowntobeeasilyattackedduetotheeasysetupoffakeaccounts

FakeAccounts,Clicks,RatingsandReviews

Agenda• Introduction• Today’sWeakOnlineReputationMetrics• ComputationalTrustEngines• TowardsStandardizedAttack-ResistantTrustMetrics

• Conclusion• Q&A

ComputationalTrust• Oneofitsmaingoalistoachieveattack-resistanttrustmetrics• Atrustmetricconsistsofthedifferentcomputationsandcommunications

whicharecarriedoutbythetrustor(andhis/hernetwork)tocomputeatrustvalueinthetrustee

• Atrustvalueisthedigitalrepresentationofthetrustworthinessorleveloftrustintheentityunderconsiderationandisanon-enforceableestimateoftheentity’sfuturebehaviorinagivencontextbasedonpastevidence,mainly:– directobservations,– recommendations fromanidentified recommender,– reputationasanaggregatedvaluefromnotclearlyidentified recommender(s).

• 3maintypesoftrustareconsideredinsocialresearch:– interpersonal trust,– dispositional trust,– systemtrust.

• Interpersonaltrustiscrucialwhensystemtrustcannotbeenforced,forexample,intheubiquitouscomputingworldoftheInternetofThings(IoT).

[Seigneur,2005]

McKnight&ChevernyTrustSocialModel

TrustEngineandTrustMetricsAttacks

• Thetrustmetricsareattackedbymeansof:– Identityusurpationattacks– Identitymultiplicityattacks

• Douceur’sSybilAttackisthemostwell-known– Coalitionsofmotivateduserscomparedtootherlazyuserswhodonotrate

Trust Engine’s Security Perimeter

Decision-making

ER

VirtualIdentities

Trust ValueComputation

Risk Analysis

Decision

RequestEvidenceManager

EvidenceStore

ResearchRepresentationsofTrustValues

[Marsh,2016]

[SECURE,2005]

[WangandVassileva,2003]

Agenda• Introduction• Today’sWeakOnlineReputationMetrics• ComputationalTrustEngines• TowardsStandardizedAttack-ResistantTrustMetrics

• Conclusion• Q&A

RandomAttack

4 randomly attacked9 directly compromised20 not compromised

NetworkTopologyEngineeredAttack

4 most connected attacked20 compromised9 not compromised

TrustTransfer:Sybil-attackResistantTrustMetric

(100,2)

(60,5)(180,0)(90,3)

(48,1)

(70,0)(12,0) (12,0)

à (36,1)

(100,2)

(60,5)(180,0)(90,3)

(48,1)

(70,0)

(12,0)

12fakedeventsmayhavebeenintroducedinthenetwork

[Seigneur, 2005]

TrustTransferExample

RecommenderSearchPolicy(RSP)

RecommendationPolicy(RP)

Thesearchforrecommendersmaybeextendedtocontactsofrecommenders.

?

Thetotalamountoftrusttransferredmaybesharedbetweenseveralrecommenders.

R

TS

10positiveoutcomesneeded

Start:R(22,2)

Start:S(32,2)

End:R(12,2)S(10,0)

End:S(22,2)

S(10)?T(10)?

YesYes

[Seigneur, 2005]

Conclusion

• Caremustbetakenwhenstandardizingtrustinordertonotdeceivetheusersandkeeptheirtrustinthetruststandard

• Attack-resistanttrustmetricsshouldbeopenandeasytobereviewedbytheresearchcommunity

• Ideally,themostattack-resistanttrustmetricsshouldbestandardized

Q&A

• Thanksforyourattention!• Jointhethe290+Trustcompcommunitymembers– http://www.trustcomp.org/group-mailing-list– ACMSACtrust/reputationTRECKtrackCFP• Deadline:15th September2016

Jean-Marc.Seigneur@reputaction.com