Trust in decentralized anonymous marketplaces

Zindros, Dionysios; Ζήνδρος, Διονύσιος

dc.contributor.author	Zindros, Dionysios	en
dc.contributor.author	Ζήνδρος, Διονύσιος	el
dc.date.accessioned	2016-07-18T09:47:15Z
dc.date.available	2016-07-18T09:47:15Z
dc.date.issued	2016-07-18
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/43147
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.12527
dc.rights	Αναφορά Δημιουργού 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by/3.0/gr/	*
dc.subject	Ψευδωνυμία	el
dc.subject	Ταυτότητα	el
dc.subject	Εμπιστοσύνη	el
dc.subject	Αποκέντρωση	el
dc.subject	Αγορά	el
dc.subject	Web-of-trust	en
dc.subject	Cryptocurrency	en
dc.subject	Bitcoin	en
dc.subject	Proof-of-burn	en
dc.subject	Openbazaar	en
dc.title	Trust in decentralized anonymous marketplaces	en
heal.type	bachelorThesis
heal.classification	Cryptography	en
heal.classificationURI	http://data.seab.gr/concepts/1d5032de48e058a3bff46c7446dbde3e5c392ea4
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2015-11-30
heal.abstract	This work introduces a decentralized anonymous marketplace. We study the nature of such marketplaces, and we present our implementation of a practical such marketplace which we call OpenBazaar. We then focus our study on the security and trust aspect of such a marketplace. We explore the security implications of decentralization and anonymity, and propose several mechanisms to achieve trust. Our proposals include traditional secure software development mechanisms, which we have applied in practice in our implementation. We also propose the use of an anonymity-preserving transport layer. More importantly, we explore how cryptocurrency mechanisms can be used to achieve trust without the need of central third parties, through the particular mechanisms of arbitration, multisigs, and mutually assured destruction. The cryptographic and game theoretic properties of such schemes are explored, and an implementation using bitcoin is studied. We also propose novel attacks on these schemes. Our contribution includes several mechanisms of achieving trust. We introduce a new form of web-of-trust in which multiplicative rules are used for trust transitivity, while decentralization, security, and anonymity are preserved. We explore the anonymity and security properties of such webs-of-trust and discuss separation attacks. Our contribution also includes the use of proof-of-burn mechanisms to build identities, for which we provide an implementation. Finally, we also contribute with anonymous decentralized naming of stores, for which we also provide an implementation using Namecoin.	en
heal.advisorName	Παγουρτζής, Αριστείδης	en
heal.committeeMemberName	Ζάχος, Ευστάθιος	en
heal.committeeMemberName	Κιαγιάς, Άγγελος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ηλεκτρολόγων Μηχανικών και Μηχανικών Υπολογιστών	el
heal.academicPublisherID	ntua
heal.numberOfPages	123 σ.
heal.fullTextAvailability	true