SECURE VANET VIA NAMED DATA NETWORKINGi.cs.hku.hk/fyp/2015/report/final_report/SO CHEUK YIU_10973721... · SECURE VANET VIA NAMED DATA NETWORKING HKU COMP4801 (FYP) ... Data Networking

SECUREVANETVIA

NAMEDDATA

NETWORKINGHKU COMP4801 (FYP) Final Report

Cheuk Yiu [email protected] | UID: 2012530095

DesigninganewsecurityprotocolforprivacypreservingidentityverificationinV-NDN

(Vehicularad-hocnetworkviaNamedDataNetwork)

17APRIL2016

1

Summary

VehicularAd-hocNETwork (VANET) is a typeof infrastructure-less networkmainly for inter vehicle

communication through wireless medium. Named Data Networking (NDN) is a data-oriented

networkingmodel. Itprovidesagoodnetworkingmodel forcommunicationbetweenvehiclessince

mostoftheVANETapplicationsreliesonsharinginformationbetweenvehicles.

Onnamed-data.net, there is a specification forNamedDataNetworking (NamedDataNetworking:

Motivation&Details-NamedDataNetworking(NDN)).TheprotocoloverviewspecifiesthatNamed

DataNetworkingprotocolaimstoreplaceIPonthenetworkinglayer.Thereisalsoa“VANETviaNamed

Data Networking” (Giulio Grassi) publication on named-data.net. It contains a NDN protocol for

effectivecommunicationbetweenvehiclesthroughvehicletovehicle(V2V)communicationbyutilizing

thenatureofwirelesscommunicationprotocol,whichisbroadcastingtoreducetheamountofpacket

needtoberesendbynodes.

Currently,twoprotocolshavebeendesigned.Thefirstone,isaprivacypreservingidentityverification

inVANETwithNDNdesign.ThisdesigntriestomergethecurrentpopularPublicKeyInfrastructureinto

VANETwithNDN.Thereareseveraldiscussionsonhowtodistributethepublickeyeffectivelyunder

thesituationthatthereisonlyvehicletovehiclecommunication.

Thesecondone,isadatafusionprotocolfordeliveringinformationtoreceiverinspecificarea.Itutilizes

GPSlocationdataasakeyforcryptography.Oneremarkablefeatureofthisdesignisthatnopreshare

keyisneeded.Aslongasthesenderhasthetimestampandlocationinfo,thekeycanbeconstructed.

Intheend,thereisasectiononsuggestingwhatcanbefurtherresearchedinNamedDataNetworking

andinVehicularAd-hocNETwork.

2

Contents

Summary..................................................................................................................................................1

Contents...................................................................................................................................................2

Introduction.............................................................................................................................................4

Background..............................................................................................................................................5

Purpose....................................................................................................................................................6

Previousworkinthefield.........................................................................................................................7

Privacypreservingidentityverificationdesign........................................................................................8

Summary..............................................................................................................................................8

Introduction.........................................................................................................................................8

SecurityschemeforVANETinNDN......................................................................................................8

Privacypreserving................................................................................................................................9

Cryptographyalgorithmselection......................................................................................................10

Identityverification............................................................................................................................10

PublickeysigninginNDNwithRoadSideUnit(RSU).........................................................................11

NDNsigningwithsmallmodification.............................................................................................11

FullNDNapproach.........................................................................................................................12

Distributingpublickey/Certificate....................................................................................................13

Passiveapproach............................................................................................................................13

Activeapproach..............................................................................................................................15

3

Dynamicactiveapproach...............................................................................................................18

Certificateincludedapproach........................................................................................................21

Hybriddynamicapproach..............................................................................................................23

Datapacketverifying..........................................................................................................................26

Certificaterevocation.........................................................................................................................26

Comment............................................................................................................................................27

DataFusionwithGPSlocationakeyDesign..........................................................................................28

Introduction.......................................................................................................................................28

Designdetails(withexample)............................................................................................................29

Explainingwithexample.....................................................................................................................30

Usage..................................................................................................................................................34

Comment............................................................................................................................................34

Currentstatus.........................................................................................................................................35

Futurework............................................................................................................................................36

Results....................................................................................................................................................37

References..............................................................................................................................................38

TableofFigures......................................................................................................................................38

4

Introduction

Vehicular Ad-hoc NETwork (VANET) is a type of wireless network mainly for inter-vehicle

communication.NamedDataNetworking(NDN)hasbeenselectedtobethenextgenerationInternet

architectureandNDNissuitableforVANETapplicationsasmostofthemrelyonsharinganddistributing

informationwithothervehicles.

The project will study how NDN can be used in VANET and design a new protocol with privacy-

preservingidentityverificationforVANETwithNDN.

ThedevelopmentofimplementingNDNwithVANETintheworldisstillatthebeginningstage.With

the new protocol, vehicle can share informationwith other vehicles without worrying the driver’s

privacybeingexposedto3rdparty.Meanwhile,themessagesender(thedriverortheonbroadunit)

identitywillstillbeproperlyauthenticated.ThiscanhelpdevelopingbetterVANETapplicationasthe

protocolhasprovidedawaytoshareinformationsafelyrunonapplicationanddeveloperneednotto

designadditionalmechanismtoprotectsender’sprivacyandverifyingsender’sidentity.

5

Background

Figure1-InternetandNDNHourglassArchitectures,from(NamedDataNetworking:Motivation&Details-NamedDataNetworking(NDN))

Infigure1,NDNwillreplaceIPpacketsbyContentchunks.RoutingwillnotbedeterminedbyIPaddress,

instead,itwillbedecidedbythecontenttag.Andthestrategylayerwilldecidehowcontentchunksbe

deliveredtonexthop.

Named Data Networking (NDN) is a kind of data-oriented networking model. It provides a good

networkingmodelforcommunicationbetweenvehiclessincemostoftheVANETapplicationrelieson

sharinginformationbetweenvehicles.

There are several application domains on VANET, from spreading information with single hops to

spreading information tomulti hopswithin various distances. Examples are electronic brake lights,

platooningandtrafficinformationsystems.

VANETapplicationsareusuallyrequiredtoshareinformationwithothervehiclesthroughdistribution.

Anexampleisroadsafetyapplication,whichisakindoftrafficinformationsystemthatsharestraffic

informationwithothervehiclesnearby.ThetraditionalIPnetworkingmodelfocusesonunicast(oneto

one)communication.Therefore,IPwillintroduceasignificantoverheadonVANETapplicationasthe

sourcenodehastomaintaintheconnectionbetweentheclientnodes.

6

WithNDN,thesendernodeisnolongerrequiredtomaintaintheconnectionbetweentheclientnodes

aseachnodecanbeturnedintoarelaynodetohelpdistributedata.Thesendernodejustneedsto

makesurethedatahasbeensentouttothenearbynodeandwillrespondtorequestswhenadditional

dataisneeded.

Purpose

Vehicular Ad-hoc NETwork (VANET) and Named Data Network (NDN) are regarded as two next

generationnetworks.VANETaimsatenhancingroadsafetywhileNDNaimsatreplacingthetraditional

IPnetwork.Researchersstartcombiningthemtoutilizetheiradvantages.

ThepurposeoftheprojectistodevelopaprotocolforVANETthroughtheNDNnetworkmodelwith

privacy preserving identity verification. For example, the message sender must be properly

authenticatedwhiletheprivacyofthedrivermustbeproperlypreserved.Attackershouldnotbeable

totraceadriver’stravellingroutebyanalyzingmultiplepacketsentbythevehicle.

Besidessecurity,performanceisalsoaconcernofthisproject.SinceVANETisawirelessinfrastructure,

bandwidthinwirelessnetworkislimited.Researchhastobedonetolookforabetterwaytotransmit

dataeffectivelyandsecurely.

7

Previousworkinthefield

Onnamed-data.net, there isa specification forNamedDataNetworking. (NamedDataNetworking:

Motivation&Details-NamedDataNetworking(NDN))TheprotocoloverviewspecifiedthatNamed

DataNetworkingprotocol isaimasreplacingIPonthenetworkinglayer.Ithasalsomentionedhow

datapacketsarebeingsignedtoprovidesourceidentification.However,thismightnotbesuitablefor

privacy-preserving identify verification as eachpacket has to be signedby using a private key. The

identity can be of the sender will be revealed if the signer’s certification contains the personal

informationofthesender.

Thereisalsoa“VANETviaNamedDataNetworking”(GiulioGrassi)publicationonnamed-data.net.It

containsaNDNprotocolforeffectivecommunicationbetweenvehiclesthroughvehicletovehicle(V2V)

communication.Thedesignofthisprotocolaimsasmakingdatapacketsspreadquicklyandeffectively.

However, italso includes theGPS locationof the sender.Asa result, the sender’s locationand the

drivingroutecanbetracedeasilyifthesenderkeeponsendinginformationout.

8

Privacypreservingidentityverificationdesign

Summary

Severalthingswillbecoveredinthefollowingsections.WewilldiscussabouthowtocombinethePublic

KeyInfrastructureintoNDNforVANET.Therewillbealargesectiondiscussabouthowtodistributethe

publickeyofasendereffectively.Intheendofthatsection,thereisanapproachwhichcombinedall

advantagesofothersapproachtogethertoformatheoreticallyoptimalapproach.

Inaddition,certificaterevocation,privacypreserving,identityverificationwillalsobecovered.

Introduction

ThisdesignfocusonimplementingthecurrentfamousPublicKeyInfrastructureintotheVANETwith

utilizingNamedDataNetworkingmodel.

Detailsofthedesignwillbementionedinthefollowingsubtopics.

SecurityschemeforVANETinNDN

Thisprojectproposedusingthedesignthatthepublickeyandcertificatearenotincludedinordinary

messagetoreducetransmissionoverhead.Thecertificatewillbelocatedasanindependentdatapacket

whichonlycontainsthecertificateandnamedwiththehashedvalueofthecertificate.

Thenamingmethodofthedatapacketis:

“/vanet/key/signed/[H(PubKey)]”

Whenavehicleneedaparticularcertificate,theOBUwillsendoutaninterestpackettoretrievethe

certificateofthesender.However,thisapproachwillintroduceotherproblemsandwillbediscussed

inthe“Distributingcertificate”section.

9

Privacypreserving

Toarchiveprivacypreserving, theprotocol has adopted thepseudo id as the id for identifying the

senderduringcommunicationbetweennodes.Eachvehiclewilluseanewidentityafteracertainperiod,

saychangingiteverydayorafteraweek.

TheOBUwillfirstgenerateapublickeyandaskthetrustedpartytosignthepublickeybysendinga

requestwiththekeyandatraceableid.OncetheOBUreceivedthesignedpublickey,thesenderwill

usethatkeytosigneverypacketitsends.Thesenderidisthehashedvalueofthepublickey.

Example:

1. Alicegenerateanewpublickey

2. Aliceencryptthefollowitemswiththetrustedpartypublickey

a. Thenewpublickey

b. Alice’straceableidentity

3. Alicesendtheencryptedpackettothetrustedpartyandrequestforsigning

4. Thetrustedpartyverifytherequestandsignthepublickey

5. Thetrustedpartyencryptthecertificate(signedpublickeyincluded)withAlice’snewpublickey

6. ThetrustedpartysendbacktheencryptedcertificatetoAlice

TheOBUcanalsogenerateasetofkeysandrequestforsigningforlateruse.Thiswillallowthesigner

tochangekeywithamoredynamicschedulewithoutbeingrestrictedbytheconnectionbetweenthe

trustedpartyandtheOBU.

10

Cryptographyalgorithmselection

The design of this implementation select Elliptic Curves Cryptography as the algorithm for signing

packetsanddata.

ConsideringthecomputationpowerofOBUonvehicleislimited,anefficientcryptographyalgorithm

hastobeselectedtoprovidebetterperformanceonsigningandverifyingpackets.

Asmentionedfrom“PerformanceAnalysisofIdentityManagementintheSessionInitiationProtocol

(SIP)”(YacineRebahi),theperformanceofECDSAismuchbetterthanRSA.

ThiswillprovidebetterperformancewhileprovidingsamesecuritylevelasRSAundersameparameters.

Asaresult,packetprocessingcanbefasterandtheoverheadoftransmittingpacketscanbereduced.

Identityverification

Whenthere isaneedtoretrievethereal identityofaparticularsender,wecantakethesender id

(eitherthehashedvalueofthesenderidorthecertificate)tothetrustedpartyandaskforthereal

identity.

11

PublickeysigninginNDNwithRoadSideUnit(RSU)

NDNsigningwithsmallmodification

ToutilizeNDNinthecurrentdesign, thefollowingmechanismwillbeadoptedforsigning.The

followingdesigndoesnotrequireothernetworkingprotocolstacktocompletetheoperation.

1. First,thetrustedpartyinterestedontheprefix

“/vanet/key/signing/”

ItwillalsomodifytheintermediatenodenottokeepanypacketinthePITonthisprefix

2. Second,theOBUwillinterestontheprefix


3. Third,theOBUwillmakeasignrequestbysendingdatapacketwiththename

“/vanet/key/signing/[H(PubKey)]”

4. Fourth,thetrustpartywillsendthesignedcertificatewiththename


Comment

However,thisdesignrequiredamodificationontheNDNdesign.AstheoriginaldesignofNDNwillkeep

datapacketintotheCStableandemptytheentryinthePITtable.

12

FullNDNapproach

ThereisanotherdesignthatcanstillfullyutilizeNDNprotocolwhiletheperformancewillbereduced

duetothepublickeywillbeencodedintothenamefiledoftheinterestpacket.

1. Frist,theOBUmakeasignrequestbysendingainterestpacketonname

“/vanet/key/signed/[base64(PubKey+traceableId)]”

Wherethepublickeyandthetraceableidwillbeencodedinbased64formatandincludedinthe

namefiledoftheinterestpacket

2. Second,thetrustedpartywillverifytherequestandsignthepublickeyandreturnthesigned

certificatebyincludingitinthedatapacketwiththename

“/vanet/key/signed/[base64(PubKey+traceableId)]”

3. Third,theOBUwillreceivethesignedcertificatefromthedatapacket.

Comment

However,thisdesignhasseveralproblems:

1. IftheOBUrequestforsigningwhilethevehicleismoving,theOBUhastoresendtheinterest

packet since not all RSU will contain the interest entry in the PIT table. This will increase the

overheadasthesizeoftheinterestpacketismuchbiggerthanthepreviousdesign.

2. TheRSUcannothelpspreadingthecertificateasthenameofthedatapacketisnotthehashed

valueofthecertificatewhichisthesenderid.

13

Distributingpublickey/Certificate

Passiveapproach

Themostpopularapproachtodistributecertificateinnameddatanetworkwasapassiveapproach.

When a consumer received a packet with unknown sender, which is the case that the sender’s

certificateisnotlocatedinconsumer’sidstore.Theconsumerwillsendaninterestpacketannouncing

itisinterestedonaspecificcertificateandwaitforthecertificatesendbackfromtheproduceroran

intermediatenode.

Pseudocode

Send_data(){

If(interest_packet.request_certificate()){

send_certificate()

}else{

send_data()

}

}

Performanceanalysis

Assumethefollowingparameter:

1. EachOBUcansendoutapacket (EitheraVANETapplicationpacket;anauthenticationrelated

packet;aninterestpacket)onceasecond.

2. Thesenderwillalwaysresponsetotheinterestpacketwhichrequestingthecertificate

14

Case1–Everyminute,50%oftheneighborwillbechanged.

SotheOBUcansend60packetsperminutes.With50%oftheneighborchangedinaminutes,itwill

have50%ofthepacketsallocatedforsendingcertificatewhichis30packetsforsendingcertificateina

minute.

Case2–Everyminute,25%oftheneighborwillbechanged.

SincetheOBUcansend60packetsperminute,with25%changingrateofnearbyvehicles;theOBUhas

tosendabout15packetsforit’scertificate.Whichtheoverheadis25%(15packets/60packets).

Itcanbeobservedthattheoverheadofbeingusedforsendingsender’scertificateisbeinglinkedwith

theneighborchangingrate.Whenanewvehicleappears,thenewvehiclewillrequestforthesender’s

certificate.

Comment

However,inVANETapplication,thismethodmightnotbeafeasiblewaytodistributekey.Considering

someVANETapplicationrequirelowlatencyonreceivingpacket,forexample,electronicbreak.Ifthe

carwhichbehindthesenderdoesnothasthecertificateofthesender,thelaternodewillsendoutan

interestpackettoretrievethecertificate.Thisapproachwillintroduceahugedelayandwillintroduce

accidenceifthekeyexchangeisnotfastenough.

15

Activeapproach

Herewe propose anothermethod to distribute certificate. Instead of taking the passive approach

mentionedabove,wecantakeanactiveapproachtodistributecertificate.Inthisapproach,insteadof

waitingforaninterestpacketarrivetotheproducer,theproducerwillsendoutit’sowncertificateout

inafixedschedule,forexample,every10second.

Pseudocode

Send_data(){

If(last_cert_send_time–current_time>=10){

send_certificate()

last_cert_send_time=current_time

}else{

send_data()

}

}

Performanceanalysis


1. EachOBUcansendoutapacket(EitheraVANETapplicationpacket;anauthenticationrelated


2. Thesenderwillnotsendoutit’sownscertificateoutofitsscheduleevenitreceivedaninterest

packet.

16

Case1–Everyminute,50%ofitsnearbyvehiclechanged,sendingcertificateonceevery9packets.(1

in10datapacketsiscertificatepacket)

SincetheOBUwillnotsenditowncertificateoutofit’scertificatesendoutschedule.Theamountof

certificatepacketsentare6inaminute(60*10%).




certificatepacketsentarestill6inaminute(60*10%).









17

SincetheOBUwillnotresponsetointerestpacketinstantlyanditwillonlyfollowitownscheduleto

sendout certificate, theoverheadof beingused to sendout certificated is beingboundedwith its

scheduleinsteadodthechangingrateofneighbor.

Comment

However,thismethodhasadisadvantagethatthenumberofcertificatebeingsentistoomanyandtoo

frequent.Inaddition,itwillnotresponsetointerestpacketinstantlyandwillcreateincidencesdueto

consumerfailedtoreceivethecertificate.

18

Dynamicactiveapproach

There isabettermethoddeveloped inthisproject,whichcertificatecanbedynamicallydistributed

basedondemandandneeded.ThedesignfeatureseveryOBUtocontainaneighbortablewhichwill

storeinformationaboutvehiclesnearby.

ThisdesignassumethateveryOBUwillsendoutitsstatuswhichissimilartothe“AutomaticDependent

Surveillance–Broadcast” (ADS-B)system,asystembeingused inaircraft toshare informationwith

otheraircraftsinairspace.

TheOBUwilllistenoneverypacketreceivedfromneighborvehiclestomaintainitsneighbortable.If

theOBUfoundanewneighborshowup,itwillsendoutitcertificate.

ThiswillallowothervehicletoreceivethecertificatequicklywhileallowingtheOBUtosendoutuseful

informationinsteadofauthenticationinformation.

Pseudocode

Send_data(){

If(neighbor_table.has_new()){

send_certificate()

}else{

send_data()

}

}

19

Performanceanalysis





packet.

3. The senderwill adjust it own certificate sendout schedule basedon the information on its

neighbortable.

Case1–Everyminute,50%ofthevehiclewillbechanged.

Inoneminute,itneedtosendoutmaximum30datapacketfordistributingcertificate.Thissendout

action isbasedonthechangesonneighbortable,whenanewvehicleappears, itwill sendoutthe

certificate.




certificate.

20

Comment

Itcanbeobservedthattheperformanceisquitesimilartothepassiveapproach.Theonlydifferent

between this design and the passive approach is; instead of waiting for an interest packet which

requestingforthesender’scertificate,itwillsendoutit’sowncertificateonceitnoticeanewneighbor

hasappeared.Thiswill allowother vehicle to verifyurgentdatapacket sinceother vehiclehas the

sender’scertificatealready.

Thisapproachcanprovidebetterperformancebydecreasingthenumberofcertificatebeingsentout

sincethesendingcriteriaisnotbasedoninterestpacketbutbasedonthenumberofnewneighbor

appear.Ifseveralnewneighborappearedinthesametimeslot,itwilljustsendoutthecertificatedata

packetonceinsteadofmultiple.

However,therearestillsomecornercase,forexample,whenthefirstpacketreceivedbyneighboris

anurgentpacket,theneighbor’sOBUcannotresponsetothepacketinstantlysincetheconsumerhas

nosender’scertificate.

21

Certificateincludedapproach

Insteadofsendingthecertificateinadifferentpacket,thesender’scertificatecanbeincludinginthe

senderfield.ThisapproachcanbeimplementedwiththeoriginalNamedDataNetworkingmodel.

Soeachtimeadatapacketisbeingsent,thecertificatewillbeincluded.Consumerwithnosender’s

certificatedonotneedtorequestforthesender’scertificateasithasbeenincludedinthedatapacket.

Pseudocode

Send_data(){

Send_data_with_cert()

}

Performanceanalysis




2. OBUwillnotsenditowncertificateasadedicatedpacketevenaninterestpacketwhichrequest

forit’scertificate.


Inoneminute,itwillsendout0certificatepacket.Sincealldatapacketitsendsoutwillincludedthe

certificate.


Itissameascase1,nocertificatepacketwillbesentout.

22

Comment

This approach seemsprovidingbetterperformance in termsofpacketbeingused for sendingdata

packet. This also allow consumer to verify urgent data packet immediately. However, the time for

sendingeachpacketwillbemorethananyotherapproachmentionedbeforeasthecertificateisbeing

included,theoverheadappearedineachpacketheader.Bothsendersandconsumersrequiremore

timetosendandreceivedatapackets.

Itisalsoimportanttonotethattheamountofbandwidthinwirelessspaceislimited,itisimportantto

reduceoverheadoneachpacketbeingsenttoallowmoreusefuldatabeingsentandshared.

23

Hybriddynamicapproach

Lastbutnotleast,weproposeanothermethodtodistributecertificate.Thisapproachcombinesboth

thedynamicactiveapproachwithanothersecurityschema,the“Certificateincludedapproach”.

Insteadof forcingeverydatapacketcontainsonly thesender’s id in thesender field,wecanallow

urgentpacketcontainthecertificateinthesenderfieldinsteadofthesenderid.Thiswillincreasethe

overheadofsendingtheurgentpacket,astheheadersizeofthesenderfieldislarger,whilethisalso

provideseveralbenefit.

First, consumernodewillable toverifysender’s identity immediately.Second,consumercansafely

relaytheurgentpackettoothervehiclewithoutrepackingthepacketwithitownsignature.Thiswill

providebetterrelayperformanceforurgentinformation.

Inaddition,OBUwillnotsendoutit’scertificateimmediatelyafteranewneighborappear.Itwillcheck

whetherithassentoutacertificaterecently,ifyes,itwillsenditafterwardbasedonascheduler.

Pseudocode

Send_data(){

If(neighbor_table.has_new()&&last_send_cert_time–current_time>=10){

send_certificate()

last_send_cert_time=current_time

}else{

send_data()

}

}

Send_urgent_data(){

Send_with_certificate()

}

24

Performanceanalysis





packet.

3. The senderwill adjust it own certificate sendout schedule basedon the information on its

neighbortable.

4. Thesenderwillsendoutcertificatepacketmostlyoncein10seconds.




certificate.However,itwillnotsendcertificatepacketifithassentoutonewithin10secondsbefore.




certificate.However,itwillnotsendcertificatepacketifithassentoutonewithin10secondsbefore.

25

Comment

Theworstcaseperformanceofthisapproachwillbethesameastheactiveapproach.Theoverheadof

beingusedtosendoutcertificatedisbeingboundedwithitsscheduleinsteadodthechangingrateof

neighbor.Whileitalsoenjoysbenefitfromthedynamicapproach(sinceitbasedondynamicapproach)

whichitsendsoutcertificatepacketonlyifnewneighborappears.

Unlikethe“Certificateincludedapproach”,certificatewillnotbeincludedineverydatapacket.Thiswill

reducetheoverheadforsendingeachdatapacket.Whichwillreducethebandwidthusedforsending

datapacket.

In addition, it also eliminates some comer cases appeared in the dynamic active approach as the

sender’scertificatewillbe included inthesenderfield forurgentdatapacket.Consumernodeswill

alwaysabletoverifysender’sidentityforurgentpacket.

26

Datapacketverifying

InthedesignofNamedDataNetwork,whenaconsumerreceivedadatapacket,theconsumerwill

verifywhetherthepackethasbeensignedproperly.Ifthedatapacketisnotbeingsingedproperlythe

packetwillbedropped.Iftheconsumerhasnocertificateofthesenderforverifyingthepacket,itcan

chooseeitherwaitforthecertificatearriveorsimplydroppingthepacket.

Itcanbeduetoimproperdatasigning;thecertificateisnottrustedbyconsumerortheisnotsignedby

acertificatesignedbytrustedparty,theconsumercandropthepacketinthiscase.

Certificaterevocation

Thisprojectsuggestsusingcertificaterevocationlistasamediumtodistributealistofcertificatewhich

hasbeenrevoked.TheCRLcanbeeitherafullCRLoradeltaCRL.Thelistshallbedistributedthrough

NDNdatapacket.

Toarchivethis,everyOBUwillinterestonprefix“/vanet/crl/”.ItwillallowrelayCRLordelta-crlpacket

toothernodes.ThetrustpartydoesnotneedtosigntheCRLsinceNDNdatapackethastobesigned

bysender.

In addition, theOSCP protocol can also be implement intoNDN in VANET.We can create a prefix

“/vanet/oscp/”forhandlingcertificatestatusdata.Whenaconsumerwanttoknowthelateststatusof

acertificate,itcansendainterestpacketwithname“/vanet/oscp/[sender’sid]”.

27

Comment

Severaldesignsofdistributingcertificatedhasbeencoveredinthisreport.Withthehybriddynamic

approach,whichcombinealladvantagesofdifferentdesignstogetherwithalittletradeoffforurgent

datapacket;itallowsvehiclesinVANETutilizethebandwidthinthewirelesschanneleffectively.

MostefforthasbeenputintocombiningPublicKeyinfrastructureintoVANETwithNDNandpublickey

/ certificate distribution from sender. Additional explanations have to be added to describe how

certificateshallberevokedandhowdatapacketshallbeverified.

Thecurrentdesignstillrequiretheroadsideunitconnectedtoanetworkwhichcanreachthetrusted

partyforcertificatesigning.Althoughmethodshavebeenproposedinthisprojectonhowtosigned

publickeywithroadsideunit,thismethodcannotbeworkonsituationthatnoroadsideunitisgiven.

28

DataFusionwithGPSlocationakeyDesign

Introduction

Currently, a protocol has been designed for sharing informationwith other vehicleswhich located

withinaspecificareainaspecifictimerange.Forexample,thesendercandecidesharinginformation

withvehicleswhichislocatedwithinabout50metersradiusfromthesenderat2015-10-1112:32:37.

Toarchivethis,anencryptionalgorithmisrequiredtoencryptthedata.SinceNDNisanetworkmodel

whichissimilartomulticast,anewkeydistributingmethodhasbeendevelopedtomakegooduseof

thisproperty.EveryvehiclewillcontainaGPSunittorecordtheirGPSlocation.Eachrowintherecord

tablewillcontaintheGPSlocationandthetimestamp.TheformatofthelocationvalueisWGS84.

Theproperty ofWGS84 is that themoredecimal places given in the value, themore accurate the

locationwill be. In otherwords, considering using this property as a key for encryption to restrict

decoderinaspecificarea.Thelessdecimalplacesbeingusedasthekey,thelargertheareawillbe.

29

Designdetails(withexample)

Thesenderwillsendoutthepacketwiththefollowingdata:

1. Thetimestampoftheinformationgenerated,forexample,“2015-10-1112:32”

2. Theaccuracyofthelocationvalueforthekey(howmanydecimalplaces),forexample,“1”.

3. Theencryptedinformation.

4. Theidofthevehicle.

5. Thehashedvalueofthekey.

Theexampleabovewillcreateaspecifiedareawithsize11kmnorth-southand8.5kmeast-west.Only

vehiclewhichlocatedinthesamespecifiedareaofthesenderatthemoment2015-10-1112:32will

knowtheexactkeyfordecryption.Receivercanretrievethekeyfromtheirrecordtablebyusingthe

timestampprovidedinthepacketandtruncatingthelocationbytheaccuracyspecifiedinthepacket

anduseitasadecryptionkey.

Thehashedvalueofthekeyprovidesamechanismforreceivertocheckwhethertheyhavethecorrect

keytodecryptthemessage.Thisenablethereceiverputthecomputingresourceondecryptingpacket

whichistargetforhim,sothatthelessresourcewillbewastedontryingtodecryptmessagewhichis

not forthereceiver.Sinceahashedvaluecannotbereversedtotheoriginalvalue,attackercannot

retrievethekeysimplybyanalyzingthehashedvalue.

30

Explainingwithexample

Tracklogofthreevehicles

Hereisthetracklogofthreevehiclesinashorttimeperiod.

Figure2-Tracklogofthreevehiclesinashorttimeperiod

These track log showswhere thecarexistatdifferent time.The first column is the timestamp, the

secondcolumnisthelatitudeandthethirdcolumnsisthelongitude.Thesetracklogswillbeusefurther

inthefollowingsectionsonexplaininghowitworksasankeyforsharinginformationwithdifferent

receivers.

31

CarAsendoutthefirstpacket

When car A send out the first packet at time “1:00:00”, it will send out a packet with following

parameter:

1. Timestamp:2016-01-0101:00:00

2. Accuracy:0(ignorealldecimalplace)

3. Key:(40,-74)

4. Keyhash:hashedvalueofkey(40,-74)

Figure3–Cars’tracklogswithresultshownattime01:00:00

WhencarBandcarCreceivedthepacketfromcarA,theywillfirstcheckoutthetimestampinthe

packet.Thentheywillextractthecorrespondinglatitudeandlongitudevaluefromtheirtracklog.Next

theywillextracttheaccuracyvaluefromthepacketsothattheywillknowhowtoconstructthekey.In

thiscase,bothcarwilluse(40,-74)asthekeyfordecoding.Bothvehiclewillcomputethehashvalue

ofthekeybeingusedandcompareitwiththekeyhashfromthepacket.Ifthekeyhashvaluesarethe

same,theydecodethepacketcontent.

Inthiscase,bothcarBandcarCwillabletodecryptthepacketsincetheywereinthesamelocationas

carAandwithintheaccuracylimit.

32

CarAsendoutthesecondpacket

WhencarA sendout the secondpacketat time“1:01:00”, itwill sendoutapacketwith following

parameters:

1. Timestamp:2016-01-0101:01:00

2. Accuracy:0(ignorealldecimalplace)

3. Key:(41,-74)

4. Keyhash:hashedvalueofkey(41,-74)

Figure4–Cars’tracklogswithresultshownattime01:01:00

Now,carBandcarCwillfollowthesameprocedurementionedinthepreviousexample.However,car

Cwilldiscoverthatit’skeyhashedvalueisnotthesameastheonefromthepacket,sincecarConly

knowthekey(39,-74)butnotthekeyusedbycarAfroencryption,whichis(41,-74).CarCwillnottry

todecryptthedatapacketsincecarCdoesnothasthecorrectkey.

CarBwillstillabletodecryptthedatapacketsincecarBhassufficientinformationtoreconstructback

thekey.

33

CarAsendoutthethirdpacket

When car A send out the third packet at time “1:02:00”, it will send out a packet with following

parameters:

1. Timestamp:2016-01-0101:02:00

2. Accuracy:1(keeponedecimalplace)

3. Key:(401,-740)

4. Keyhash:hashedvalueofkey“(401,-740)”

Ascanbeseen,thistime,carAsettheaccuracyvalueto1.Asaresult,thekeyis(401,-740)insteadof

(40,-74).

Figure5-Cars'tacklogswithresultshownattime01:02:00

Inthiscase,bothcarBandcarCarenotabletodecryptthepacketsentbycarA.

ForcarB,thekeyitwilltrytodecryptthepacketis(416,-740).CarBisnotusingthekey(41,-74)this

timebecausetheaccuracyparameter is1.WhencarB try tocomparethehashedvalueof thekey

constructedfromit’stracklogandtheonefromthemessagepacket, itwillrealizethatthevalueis

differentandcarBwillnottrytodecryptthemessage.

ForcarC,itwillableabletodiscoverthekeyconstructedfromit’stracklogisdifferentfromtheone

usedbycarA,sincethehashedvalueofthekeyisdifferent.

34

Usage

Thisprotocolcanbeusedinvarioussituation,includedbutnotlimitedinVANETapplication.Itcanbe

use in advertisement to general public in city, information sharingwithunknown receiverwhoare

locatednearthesender.

Comment

Althoughthisdesignenablesprivacypreservingidentityverificationbyknowingwhowassendingthe

packet(TheIdofthevehicle)butnotknowingwhereexactlythedriverislocated,thisdesignhasseveral

restrictions.

First,thesizeofthespecifiedareaisrestrictedbythedesignofWGS84,asaresult,thescaleofthesize

oftheareaisdividedby10.Forexample,with1decimalplace,theaccuracyinlatitudeis11km;with2

decimalplace,theaccuracyinlatitudeis1.1km.Sendercannotdecidetheaccuracyinlatitudetobe

5km.

Second,thisprotocolcannotbeusedinareawithnoGPSsignal,forexample,insideatunnelorarea

withlargeandthickcloudwhichfilterouttheGPSsignal.

AdditionalworkshastobedonetofurtherimprovetheprotocolandtestitwithintheNS3simulator.

35

Currentstatus

At this moment, two different designs have been created in this project to address two different

problems.First,adesignforimplementingthePublicKeyInfrastructureintotheVANETwithNamed

DataNetworkingmodel.Second,adatafusiondesignwhichcanbeusedforfilterdataandtargeting

specificreceivingnode.

DuringthestageofdesigningdifferentapproachondistributingcertificateinVANETwithNDN,several

problemsinNDNhasbeendiscovered.Forexample,thebehaviorbetweenthePITandpacketreturn

theproducerhasnotbeenproperlyspecified.Asaresult,additionefforthasbeentakento further

studythebehaviorofPITtable.

The simulatorNS-3hasbeen taken into studya fewweeksafter the startof the second semester.

HoweverduetothecomplexityofthesetwodesignandtoomanyoptionsintheNS-3simulator,there

was insufficient time to implement designs into the simulator for extracting performance data for

analysis.

For the Privacy preserving identity verification design, since theNS-3 simulator does not contain a

generalAPIforgeneratinginterestpacketbasedonpacketreceivedoneachnode,itrequiresaddition

timeandefforttoimplementtheselogicsintothesimulatorforsimulation.

36

Futurework

Severaltopicscanbedoneinthefutureasanindependentproject.

1. SigningrequestonpureNDNwithbetterperformance.

Currently,thecommunicationmodelbetweenconsumerandproducerisbasedonarequestbase.

Consumercanonlysenddatatoproducerasainterestpacket,datacanonlybeencodedinbase64

formatandincludedinthenamefield.

2. Allowconsumerpushingdatatoproducer

Asmentionedabove,consumercanonlysenddatatoproducerbyincludinginformationasabase64

formatandincludedinthenamefieldofinterestpacket.Thisisnotanefficientapproachwhenwe

compareitwithdatacanbesendasbinarydata,likehowIPdoesthesedays.Wecanstudyhowcan

theprotocolbemodifiedtoallowdataincludedasabinarydataandsendittoproducer.

3. Allowproducerstreamingdata

Atthismoment,thedesignofNamedDataNetworkingisbasedonarequestandresponseapproach.

Itisimpossibleforproducertosenddatapackettoconsumerifconsumerdoesnotrequestfora

packetthroughaninterestpacket.ItispossibletoimproveNDNbyimplementingamulticastlike

featureintoitsothatproducercanpushdatatoconsumerdirectly.Itcanbedesignaswithasingle

interest packet from consumer, subsequencedatapacket share the sameprefix canbe sent to

consumerwithouttheconsumerkeeponsendingdifferentinterestpacket.

4. ImprovethePendingInterestTabledesign

Rightnow,theNamedDataNetworkingmodelhasnotdefinedhowtheintermediatereactwhena

datapacketreceivedwithalongernamethantheentryinthePIT.Howshouldtheintermediate

nodestorethedatapacketintothecontentstore?Shoulditmakethedatapackethasthesame

nameastheoneinthePIT?Additionalresearchandworkhastobedonetoimprovethedesign.

37

Results

Two designs have been created for addressing two different issue. The first design is for privacy

preserving identity verification. The design has suggested a way to implement the Public Key

InfrastructureintoVANETwithNDN.Inaddition,ithasalargesectionfocusingonhowtoimprovethe

performanceondistributingpublickeysduringtransmissioninthecasethatnoroadsideunitexists.

The second design, which is the data fusion with GPS location data as a key. This design allow

informationsharedwithaudiencesnearbywithfinecontrolontheareaoftheaudiences.ItutilizesGPS

locationandtimestampasamediumtoformthecommonkeyforcryptography.

Itwasplannedtoimplementthesetwodesignsintoasimulatortoextractperformancedataforfurther

improvementonthedesignsofthesetwoprotocol.However,thedesignoftheNS-3simulatorisfar

more complex than expected earlier and the API provided by the simulator cannot fulfill the

requirementofsimulatingthesetwoprotocol.Asaresult,additionalworkhastobedonetostudythe

simulatorandcreateadditionalimplementationforsimulatingbothdesignsandprotocols.

38

References

"Named Data Networking: Motivation & Details - Named Data Networking (NDN)." Named Data

NetworkingNDN.<http://named-data.net/project/archoverview/>.

GiulioGrassi,DavidePesavento,GiovanniPau,RamaVuyyuru,RyujiWakikawa,LixiaZhang."VANETvia

Named Data Networking." 2014. VANET via Named Data Networking. <http://named-data.net/wp-

content/uploads/2014/03/vanet_via_ndn_infocom_nom.pdf>.

YacineRebahi,JordiJaenPallares,NguyenTuanMinh,SvenEhlert,GergelyKovacs,DorghamSisalem.

"PerformanceAnalysisofIdentityManagementintheSessionInitiationProtocol(SIP)."IEEE,n.d.

TableofFigures

Figure1-InternetandNDNHourglassArchitectures,from(NamedDataNetworking:Motivation

&Details-NamedDataNetworking(NDN))........................................................................5

Figure2-Tracklogofthreevehiclesinashorttimeperiod......................................................30

Figure3–Cars’tracklogswithresultshownattime01:00:00..................................................31

Figure4–Cars’tracklogswithresultshownattime01:01:00..................................................32

Figure5-Cars'tacklogswithresultshownattime01:02:00....................................................33

Documents

SECURE VANET VIA NAMED DATA NETWORKINGi.cs.hku.hk/fyp/2015/report/final_report/SO CHEUK YIU_10973721... · SECURE VANET VIA NAMED DATA NETWORKING HKU COMP4801 (FYP) ... Data Networking