towards privacy -preserving mobile apps: a...

TowardsPrivacy-PreservingMobileApps:ABalancingActDengfeng Li1,WingLam1,WeiYang1,Zhengkai Wu1,Xusheng Xiao2,TaoXie1

1(UniversityofIllinoisatUrbana-Champaign,email:taoxie@illinois.edu)2(CaseWesternReserveUniversity,email:xusheng.xiao@case.edu)

Objective• Maximizeutilitieswhileminimizingtheamountofsensitiveinformationexposedtoprotectusers'appusagedata

Motivation• Collectingsomehighlysensitiveinformationprovideslittleornobenefittowardsdeliveringanapp’sutilities• Existingtechniqueslackcustomizedsolutionstopreserveuserprivacyatdifferentlevelswhiledeliveringuser-desirablelevelofutilityefficacy(e.g.,thenumberofenabledfeatures)

Example– Appdisplaysvideosonlyifsomesensitiveinformationispreviouslysenttoaremoteserver[1]

1.Sensitive-InputDetection• LeverageUIrendering,geometricallayoutanalysis,andNLPtoidentifysensitiveinputfields• Leveragesstaticdataflowanalysistodetectsensitiveinformation(suchasaGPSlocation)obtainedfromthesystem

4.Privacy-PreservingBalancing• Anonymizevarioussensitiveinformationwhileassuringthatthelevelofutilityefficacyisaboveauser-predefinedthreshold

3.Privacy-PolicyComplianceChecking• Checkwhetherthesensitiveinformationcollectedbyanappisprivacypreservingagainstthedeclaredprivacypolicy• Conductstaticdataflowanalysisontheappanditsbackendservertogenerateausagesummaryoftheobtainedsensitiveinformation• LeverageNLPtoannotatedeclaredprivacypolicytoextractkeyfeaturesrelatedtosensitive-informationusage• Checkgeneratedusagesummarywithextractedkeyfeaturesforinconsistencies

2.Utility-ImpactAnalysis• Anonymizeeachinput,andmeasureitsimpactontheutilitiesofanapp andproduceanutilityreport• Providemeasurementtoshowhoweachinputcontributestoanapp’sutilities

Proposedframework

[1]AndroidMalwarePromisesVideoWhileStealingContacts:https://securingtomorrow.mcafee.com/mcafee-labs/android-malware-promises-video-while-stealing-contacts/

ThismaterialisbaseduponworksupportedbytheMarylandProcurementOfficeunderContractNo.H98230-14-C-0141