Identity and Anonymity in Ad Hoc Networks

222 Pages·2009·1.39 MB·English

Faculty of Economic Sciences, Communication and IT
Computer Science
Leonardo Augusto Martucci
Identity and Anonymity
in Ad Hoc Networks
DISSERTATION
Karlstad University Studies
2009:25
Leonardo Augusto Martucci
Identity and Anonymity
in Ad Hoc Networks
Karlstad University Studies
2009:25
Leonardo Augusto Martucci. Identity and Anonymity in Ad Hoc Networks
DISSERTATION
Karlstad University Studies 2009:25
ISSN 1403-8099
ISBN 978-91-7063-248-8
Permanent link: http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-3981
© The Author
Distribution:
Faculty of Economic Sciences, Communication and IT
Computer Science
SE-651 88 Karlstad
SWEDEN
[phone]
www.kau.se
Printed at: Universitetstryckeriet, Karlstad 2009
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“No,thatisnotquiteit. Let’stryagain
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Identity and Anonymity in Ad Hoc Networks
LEONARDOAUGUSTOMARTUCCI
DepartmentofComputerScience,KarlstadUniversity,Sweden
Abstract
In ad hoc networks every device is responsible for its own basic computer ser-
vices,includingpacketrouting,dataforwarding,security,andprivacy. Mostof
theprotocolsusedinwirednetworksarenotsuitableforadhocnetworks,since
they were designed for static environments with defined borders and highly
specializeddevices,suchasrouters,authenticationservers,andfirewalls.
Thisdissertationconcentratesontheachievementofprivacy-friendlyiden-
tifiers and anonymous communication in ad hoc networks. In particular, the
objective is to offer means for better anonymous communication in such net-
works. Tworesearchquestionswereformulatedtoaddresstheobjective:
I. Howtodesignproperandtrustedprivacy-friendlydigitalidentifierstobe
usedinadhocnetworkenvironments?
II. Howtoprovideanonymouscommunicationinadhocnetworksandwhat
istheperformancecostinrelationtotheobtaineddegreeofanonymity?
Toaddressthefirstresearchquestionwestudiedandclassifiedthesecurity
andprivacythreats,enhancements,andrequirementsinadhocnetworksand
analyzed the need for privacy and identification. The analysis led us to the
relationship between security, identification, and anonymous communication
that we refer to as the “identity-anonymity paradox”. We further identified
therequirementsforprivacy-friendlyidentifiersandproposedtheself-certified
Sybil-freepseudonymstoaddresssuchrequirements.
The second research question was addressed with the design and imple-
mentation of the Chameleon protocol, an anonymous communication mecha-
nismforadhocnetworks. TheperformanceofChameleonwasevaluatedusing
a network simulator. The results were used to find out the trade-off between
anonymityandperformanceintermsoftheexpectedend-to-enddelay.
The solutions proposed in this dissertation are important steps towards
theachievementofbetteranonymouscommunicationsinadhocnetworksand
complementothermechanismsrequiredtopreventleaksofpersonaldata.
Keywords: privacy,identity,anonymity,pseudonymity,Sybilattack,security,
adhoc,andcomputernetworks.
i

Acknowledgments
You are now holding a copy of my doctoral dissertation. It is the result of my
researchstudies,butIcertainlywouldn’thavebeenabletocompleteitwithout
the collaboration and support of many others. I would not consider this work
completewithoutproperacknowledgingtheywhosomehowcontributedtoit.
First, I have Prof.Simone Fischer-Hübner to thank for giving me the op-
portunitytopursuemydoctoralstudiesunderhersupervision,forintroducing
metotheresearchfieldofcomputationalprivacy,andforprovidingadviceand
directions. Iwasprivilegedforhavingherassupervisorandalsoasafriend.
I would like to thank the European Network of Excellence FIDIS (Future
ofIdentityintheInformationSociety),PRIME(PrivacyandIdentityManage-
ment in Europe), Newcom and Newcom++ (Network of Excellence in Wireless
Communications)forthefinancialsupport.
Iamthankfulforhavebeengiventhechanceofworkingandcollaborating
with so many wonderful people with whom I share not only the authorship of
publications,butalsoproblems,solutions,ideasandsomanyhoursofinterest-
ingandfruitfuldiscussions. Theyallhavemydeepestrespect.
All my colleagues at the Department of Computer Science deserve credit
forprovidingsuchaniceandfriendlyworkenvironment. Ialsowanttothank
allpresentandformermembersofthePrivacyandSecurityGroup. Itwasan
honor to be part of such fine group. I owe a special thanks to Stefan Lindskog
andChristerAnderssonforvolunteeringtoreviewthedissertation,andalsoto
mysecondaryadvisorThijsJ.Holleboom. Prof.ErlandJonssonandmyfriends
fromChalmersUniversityofTechnologydeservemymostsinceregratitude. I
amalsothankfultotheopponentofmylicentiatethesisMatsNäslund.
I am lucky and grateful for having made such good friends during my stay
inKarlstad. TorbjörnAndersson,XimenaDahlborn,JohanEklund,PeterDely,
UlfLarson,StefanLindskog,ChristianBecker,GeZhangandStefanBerthold
definitelydeserveaspecialmention. Ialsowouldliketothankmydearfriends
MarcelCastroandRobertaAgostini. IamespeciallyfortunatetohaveChrister
Anderssonasanincrediblefriend,withwhomIhavesharednotonlytheoffice
and publications, but also very good times. Further, I am much obliged to my
dearestAlbinandLindaZuccatoforallthejoyandfunwehadtogether.
MybrotherDanielandmyeverlastingfriendsPaulodeAndréa,Bidu,Bruno
Galiotto, Luciano Maciel and Fernando Szterling deserve a big thank you for
knowing me for so long and, strangely enough, still seem to enjoy having me
around. AndthemostthatIcandoforyouistobeyourfriend.
All my gratitude goes to my parents, d.Olguinha and s.Moacyr, for their
unconditionalsupportandlove. Foreverything,Ihaveonlyyoutothank.
Karlstad,May2009 LeonardoA.Martucci
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