A P2P Optimistic Fair Exchange (OFE) Scheme For Personal Health Records Using Blockchain Technology

In today’s digital world, it is common to exchange sensitive data between different parties. There are many examples of sensitive data or documents that require a digital exchange, such as banking information, insurance data, health records. In many cases, the exchange exists between unknown and untrusted parties. Therefore, it is essential to execute the data exchange over a fair non-repudiation protocol. In digital communication, non-repudiation is undeniable evidence of one’s responsibility regarding the validity of any data he shares/receives. Usually, this is achieved by the use of a cryptographic digital signature. In this case, the parties cannot deny the authenticity of their digital signature. The protocol satisfies the fairness property if and only if it does not give the sender any advantages over the receiver or vice versa, at any step during the exchange process. Combining fair exchange and non-repudiation for digital exchange is critical in many applications and can be acquired with or without the involvement of any trusted third party (TTP). However, without the involvement of TTP, fairness becomes probabilistic, and the involvement of TTP can cause significant dependency on the third party. Therefore, a peer-to-peer (P2P) (aka offline) fair non-repudiation protocol that does not require a trusted third-party is desirable in many applications. Blockchain is designed in such a way that the network can handle the trustless environment and deliver the correct result. Thus, if the exchanges are done leveraging Blockchain, it will ensure true fairness, and at the same time, none of the participants have to deal with the trust issue. In this thesis we propose a P2P fair non-repudiation data exchange scheme by leveraging Blockchain and distributed ledger technology. The scheme combines on-chain and off-chain communication patterns to enable the exchange of personal health records between patients and healthcare providers. We provide an informal reasoning of the proposed scheme. Moreover, we propose a design and implementation agnostic to existing Blockchain platforms to enable unbiased evaluation of the proposed scheme. Finally, we make a comparative analysis of the result derived from our approach with the existing one

Fair exchange in e-commerce and certified e-mail, new scenarios and protocols

We are witnessing a steady growth in the use of Internet in the electronic commerce field. This rise is promoting the migration from traditional processes and applications (paper based) to an electronic model. But the security of electronic transactions continues to pose an impediment to its implementation. Traditionally, most business transactions were conducted in person. Signing a contract required the meeting of all interested parties, the postman delivered certified mail in hand, and when paying for goods or services both customer and provider were present. When all parties are physically present, a transaction does not require a complex protocol. The participants acknowledge the presence of the other parties as assurance that they will receive their parts, whether a signature on a contract, or a receipt, etc. But with e-commerce growing in importance as sales and business channel, all these transactions have moved to its digital counterpart. Therefore we have digital signature of contracts, certified delivery of messages and electronic payment systems. With electronic transactions, the physical presence is not required,moreover, most of the times it is even impossible. The participants in a transaction can be thousands of kilometers away from each other, and they may not even be human participants, they can be machines. Thus, the security that the transaction will be executed without incident is not assured per se, we need additional security measures. To address this problem, fair exchange protocols were developed. In a fair exchange every party involved has an item that wants to exchange, but none of the participants is willing to give his item away unless he has an assurance he will receive the corresponding item from the other participants. Fair exchange has many applications, like digital signature of contracts, where the items to be exchanged are signatures on contracts, certified delivery of messages, where we exchange a message for evidence of receipt, or a payment process, where we exchange a payment (e-cash, e-check, visa, etc.) for digital goods or a receipt. The objective of this dissertation is the study of the fair exchange problem. In particular, it presents two new scenarios for digital contracting, the Atomic Multi- Two Party (AM2P) and the Agent Mediated Scenario (AMS), and proposes one optimistic contract signing protocol for each one. Moreover, it studies the efficiency of Multi-Party Contract Signing (MPCS) protocols from their architecture point of view, presenting a new lower bound for each architecture, in terms of minimum number of transactions needed. Regarding Certified Electronic Mail (CEM), this dissertation presents two optimistic CEMprotocols designed to be deployed on thecurrent e-mail infrastructure, therefore they assume the participation of multiple Mail Transfer Agents (MTAs). In one case, the protocol assumes untrusted MTAs whereas in the other one it assumes each User Agent (UA) trusts his own MTA. Regarding payment systems, this dissertation presents a secure and efficient electronic bearer bank check scheme allowing the electronic checks to be transferred fairly and anonymously.L’ús d’Internet en l’àmbit del comerç electrònic està experimentant un creixement estable. Aquest increment d’ús està promovent lamigració de processos tradicionals i aplicacions (basades en paper) cap a un model electrònic. Però la seguretat de les transaccions electròniques continua impedint la seva implantació. Tradicionalment, la majoria de les transaccions s’han dut a terme en persona. La firma d’un contracte requeria la presència de tots els firmants, el carter entrega les cartes certificades enmà, i quan es paga per un bé o servei ambdós venedor i comprador hi són presents. Quan totes les parts hi són presents, les transaccions no requereixen un protocol complex. Els participants assumeixen la presència de les altres parts com assegurança que rebran el que esperen d’elles, ja sigui la firma d’un contracte, un rebut d’entrega o un pagament. Però amb el creixement del comerç electrònic com a canal de venda i negoci, totes aquestes transaccions s’hanmogut al seu equivalent en el món electrònic. Així doncs tenim firma electrònica de contractes, enviament certificat de missatges, sistemes de pagament electrònic, etc. En les transaccions electròniques la presència física no és necessària, de fet, la majoria de vegades és fins it tot impossible. Els participants poden estar separats permilers de kilòmetres, i no és necessari que siguin humans, podrien sermàquines. Llavors, la seguretat de que la transacció s’executarà correctament no està assegurada per se, necessitem proporcionar mesures de seguretat addicionals. Per solucionar aquest problema, es van desenvolupar els protocols d’intercanvi equitatiu. En un intercanvi equitatiu totes les parts involucrades tenen un objecte que volen intercanviar, però cap de les parts implicades vol donar el seu objecte si no té la seguretat que rebrà els objectes de les altres parts. L’intercanvi equitatiu té multitud d’aplicacions, com la firma electrònica de contractes, on els elements a intercanviar son firmes de contractes, enviament certificat demissatges, on s’intercanvien unmissatge per una evidència de recepció, o un procés de pagament, on intercanviemun pagament (e-cash, visa, e-xec, etc.) per bens digitals o per un rebut. L’objectiu d’aquesta tesi és estudiar el problema de l’intercanvi equitatiu. En particular, la tesi presenta dos nous escenaris per a la firma electrònica de contractes, l’escenari multi-two party atòmic i l’escenari amb agents intermediaris, i proposa un protocol optimista per a cada un d’ells. A més, presenta un estudi de l’eficiència dels protocols de firma electrònica multi-part (Multi-Party Contract Signing (MPCS) protocols) des del punt de vista de la seva arquitectura, presentant una nova fita per a cada una, en termes de mínim nombre de transaccions necessàries. Pel que fa al correu electrònic certificat, aquesta tesi presenta dos protocols optimistes dissenyats per a ser desplegats damunt l’infraestructura actual de correu electrònic, per tant assumeix la participació demúltiples agents de transferència de correu. Un dels protocols assumeix que cap dels agents de transferència de correu participants és de confiança,mentre que l’altre assumeix que cada usuari confia en el seu propi agent. Pel que fa a sistemes de pagament, la tesi presenta un esquema de xec bancari al portador, eficient i segur, que garanteix que la transferència dels xecs es fa demanera anònima i equitativa

Design and implementation of extensible middleware for non-repudiable interactions

PhD ThesisNon-repudiation is an aspect of security that is concerned with the creation of irrefutable audits of an interaction. Ensuring the audit is irrefutable and verifiable by a third party is not a trivial task. A lot of supporting infrastructure is required which adds large expense to the interaction. This infrastructure comprises, (i) a non-repudiation aware run-time environment, (ii) several purpose built trusted services and (iii) an appropriate non-repudiation protocol. This thesis presents design and implementation of such an infrastructure. The runtime environment makes use of several trusted services to achieve external verification of the audit trail. Non-repudiation is achieved by executing fair non-repudiation protocols. The Fairness property of the non-repudiation protocol allows a participant to protect their own interests by preventing any party from gaining an advantage by misbehaviour. The infrastructure has two novel aspects; extensibility and support for automated implementation of protocols. Extensibility is achieved by implementing the infrastructure in middleware and by presenting a large variety of non-repudiable business interaction patterns to the application (a non-repudiable interaction pattern is a higher level protocol composed from one or more non-repudiation protocols). The middleware is highly configurable allowing new non-repudiation protocols and interaction patterns to be easily added, without disrupting the application. This thesis presents a rigorous mechanism for automated implementation of non-repudiation protocols. This ensures that the protocol being executed is that which was intended and verified by the protocol designer. A family of non-repudiation protocols are taken and inspected. This inspection allows a set of generic finite state machines to be produced. These finite state machines can be used to maintain protocol state and manage the sending and receiving of appropriate protocol messages. A concrete implementation of the run-time environment and the protocol generation techniques is presented. This implementation is based on industry supported Web service standards and services.EPSRC, The Hewlett Packard Arjuna La

Middleware to support accountability of business to business interactions

PhD ThesisEnabling technologies have driven standardisation efforts specifying B2B interactions between organisations including the information to be exchanged and its associated business level requirements. These interactions are encoded as conversations to which organisations agree and execute. It is pivotal to continued cooperation with these interactions that their regulation be supported; minimally, that all actions taken are held accountable and no participant is placed at a disadvantage having remained compliant. Technical protocols exist to support regulation (e.g., provide fairness and accountability). However, such protocols incur expertise, infrastructure and integration requirements, possibly diverting an organisation’s attention from fulfilling obligations to interactions in which they are involved. Guarantees provided by these protocols can be paired with functional properties, declaratively describing the support they provide. By encapsulating properties and protocols in intermediaries through which messages are routed, expertise, infrastructure and integration requirements can be alleviated from interacting organisations while their interactions are transparently provided with additional support. Previous work focused on supporting individual issues without tackling concerns of asynchronicity, transparency and loose coupling. This thesis develops on previous work by designing generalised intermediary middleware capable of intercepting messages and transparently satisfying supportive properties. By enforcing loose coupling and transparency, all interactions may be provided with additional support without modification, independent of the higher level (i.e., B2B) standards in use and existing work may be expressed as instances of the proposed generalised design. This support will be provided at lower levels, justified by a survey of B2B and messaging standards. Proof of concept implementations will demonstrate the suitability of the approach. The work will demonstrate that providing transparent, decoupled support at lower levels of abstraction is useful and can be applied to domains beyond B2B and message oriented interactions.EPSRC Hat’s Newcastle operation Dr. Mark Littl

Wireless Bandwidth Aggregation for Internet Traffic

This MQP proposes a new method for bandwidth aggregation, utilize-able by the typical home network owner. The methods explained herein aggregate a network of coordinating routers within local WiFi communication range to achieve increased bandwidth at the application layer, over the HTTP protocol. Our protocol guarantees content delivery and reliability, as well as non-repudiation measures that hold each participant, rather then the group of routers, accountable for the content they download

Design and implementation of extensible middleware for non-repudiable interactions

Non-repudiation is an aspect of security that is concerned with the creation of irrefutable audits of an interaction. Ensuring the audit is irrefutable and verifiable by a third party is not a trivial task. A lot of supporting infrastructure is required which adds large expense to the interaction. This infrastructure comprises, (i) a non-repudiation aware run-time environment, (ii) several purpose built trusted services and (iii) an appropriate non-repudiation protocol. This thesis presents design and implementation of such an infrastructure. The runtime environment makes use of several trusted services to achieve external verification of the audit trail. Non-repudiation is achieved by executing fair non-repudiation protocols. The Fairness property of the non-repudiation protocol allows a participant to protect their own interests by preventing any party from gaining an advantage by misbehaviour. The infrastructure has two novel aspects; extensibility and support for automated implementation of protocols. Extensibility is achieved by implementing the infrastructure in middleware and by presenting a large variety of non-repudiable business interaction patterns to the application (a non-repudiable interaction pattern is a higher level protocol composed from one or more non-repudiation protocols). The middleware is highly configurable allowing new non-repudiation protocols and interaction patterns to be easily added, without disrupting the application. This thesis presents a rigorous mechanism for automated implementation of non-repudiation protocols. This ensures that the protocol being executed is that which was intended and verified by the protocol designer. A family of non-repudiation protocols are taken and inspected. This inspection allows a set of generic finite state machines to be produced. These finite state machines can be used to maintain protocol state and manage the sending and receiving of appropriate protocol messages. A concrete implementation of the run-time environment and the protocol generation techniques is presented. This implementation is based on industry supported Web service standards and services.EThOS - Electronic Theses Online ServiceEPSRC : Hewlett Packard Arjuna LabGBUnited Kingdo

E-commerce protocol supporting automated online dispute resolution

E-commerce now constitutes a significant part of all commercial activity; however the increase in transactions is also leading to more disputes. These disputes are becoming more frequent, more technologically complicated and more difficult in terms of traceability . This thesis focuses specifically on dispute problems related to soft products, i.e. those that are intangible and therefore requiring no physical delivery. With the growing demand for these types of products, e.g. downloadable films, music, software, and prepaid calling time, the prevention of fraudulent transactions is becoming increasingly important. Reasons for the rise in the number of fraudulent transactions include merchants being unable to see the customer to verify an ID or signature and E-commerce enabling soft-products and services to be acquired via soft delivery methods: email, download or logging in. The introductory section provides a critique of current e-commerce fraud detection and prevention techniques and shows that not all are suitable for e-commerce, especially soft-products, and therefore unable to provide complete protection against fraud. The future relating to the detection and prevention of e-commerce fraud is then discussed, leading to suggestions regarding the improvement of the current state-of-the-art technique, the Address Verification Service (AVS), which is used to accommodate the introduction of soft-products. Apart from the exchange process problems, i.e. those involving money and goods, attention is also paid to other important factors such as timing and quality that are usually neglected in these detection and prevention techniques. Dispute scenarios from many different perspectives have been analysed, viz. computer science, business, legal and that of the participants themselves. From the analyses, all possible dispute cases have been formally listed using the 'Truth Table' approach. This analysis has then led to the design of a comprehensive taxonomy framework for dispute in e-commerce. The term Online Dispute Resolution (ODR), is the online technology applied to Alternative Dispute Resolution (ADR) which is resolving disputes other than via litigation in the courts. Current ODR systems and their suitability for the e-commercial world have been examined, concluding that not all are appropriate for e-commerce situations (since most still involve a human element and often make the resolution process more costly than the actual item under dispute). The proposed solution to the problem is by automating the online dispute resolution process. The total solution is described in two parts (i) an E-commerce Transaction Protocol (ETP) forming the infrastructure where the transaction will take place and be able to accommodate any new improvements in the future, and (ii) an Automated Online Dispute Resolution (AODR) system which should automatically resolve any dispute occurring within the proposed e-commerce model. In order for the AODR to resolve any dispute, a product/payment specific plug-in (add-on) has been incorporated into the system. For illustration purposes, credit cards as a payment method has been selected and the appropriate plug-in specification for soft products and credit cards created. The concept of providing every soft product with a quality certificate has also been discussed. A concluding case study of e-commerce in Saudi Arabia has been used to test the viability of both the e-commerce dispute taxonomy and the proposed model. The case study shows the suitability of using ETP with AODR in order to resolve soft-product disputes automatically. Limitations of the work and further research possibilities have then been identified.EThOS - Electronic Theses Online ServiceDepartment of Computing Science, Newcastle UniversityGBUnited Kingdo

Keeping Fairness Alive : Design and formal verification of optimistic fair exchange protocols

Fokkink, W.J. [Promotor]Pol, J.C. van de [Promotor

Enhancing the reliability of digital signatures as non-repudiation evidence under a holistic threat model

Traditional sensitive operations, like banking transactions, purchase processes, contract agreements etc. need to tie down the involved parties respecting the commitments made, avoiding a further repudiation of the responsibilities taken. Depending on the context, the commitment is made in one way or another, being handwritten signatures possibly the most common mechanism ever used. With the shift to digital communications, the same guarantees that exist in real world transactions are expected from electronic ones as well. Non-repudiation is thus a desired property of current electronic transactions, like those carried out in Internet banking, e-commerce or, in general, any electronic data interchange scenario. Digital evidence is generated, collected, maintained, made available and verified by non-repudiation services in order to resolve disputes about the occurrence of a certain event, protecting the parties involved in a transaction against the other's false denial about such an event. In particular, a digital signature is considered as non-repudiation evidence which can be used subsequently, by disputing parties or by an adjudicator, to arbitrate in disputes. The reliability of a digital signature should determine its capability to be used as valid evidence. The reliability depends on the trustworthiness of the whole life cycle of the signature, including the generation, transfer, verification and storage phases. Any vulnerability in it would undermine the reliability of the digital signature, making its applicability as non-repudiation evidence dificult to achieve. Unfortunately, technology is subject to vulnerabilities, always with the risk of an occurrence of security threats. Despite that, no rigorous mechanism addressing the reliability of digital signatures technology has been proposed so far. The main goal of this doctoral thesis is to enhance the reliability of digital signatures in order to enforce their non-repudiation property when acting as evidence. In the first instance, we have determined that current technology does not provide an acceptable level of trustworthiness to produce reliable nonrepudiation evidence that is based on digital signatures. The security threats suffered by current technology are suffice to prevent the applicability of digital signatures as non-repudiation evidence. This finding is also aggravated by the fact that digital signatures are granted legal effectiveness under current legislation, acting as evidence in legal proceedings regarding the commitment made by a signatory in the signed document. In our opinion, the security threats that subvert the reliability of digital signatures had to be formalized and categorized. For that purpose, a holistic taxonomy of potential attacks on digital signatures has been devised, allowing their systematic and rigorous classification. In addition, and assuming a realistic security risk, we have built a new approach more robust and trustworthy than the predecessors to enhance the reliability of digital signatures, enforcing their non-repudiation property. This new approach is supported by two novel mechanisms presented in this thesis: the signature environment division paradigm and the extended electronic signature policies. Finally, we have designed a new fair exchange protocol that makes use of our proposal, demonstrating the applicability in a concrete scenario. ----------------------------------------------------------------------------------------------------------------------------------------------------------------Las operaciones sensibles tradicionales, tales como transacciones bancarias, procesos de compra-venta, firma de contratos etc. necesitan que las partes implicadas queden sujetas a los compromisos realizados, evitando así un repudio posterior de las responsabilidades adquiridas. Dependiendo del contexto, el compromiso se llevaría a cabo de una manera u otra, siendo posiblemente la firma manuscrita el mecanismo más comúnmente empleado hasta la actualidad. Con el paso a las comunicaciones digitales, se espera que las mismas garantías que se encuentran en las transacciones tradicionales se proporcionen también en las electrónicas. El no repudio es, por tanto, una propiedad deseada a las actuales transacciones electrónicas, como aquellas que se llevan a cabo en la banca online, en el comercio electrónico o, en general, en cualquier intercambio de datos electrónico. La evidencia digital se genera, recoge, mantiene, publica y verifica mediante los servicios de no repudio con el fin de resolver disputas acerca de la ocurrencia de un determinado evento, protegiendo a las partes implicadas en una transacción frente al rechazo respecto a dicho evento que pudiera realizar cualquiera de las partes. En particular, una firma digital se considera una evidencia de no repudio que puede emplearse posteriormente por las partes enfrentadas o un tercero durante el arbitrio de la disputa. La fiabilidad de una firma digital debería determinar su capacidad para ser usada como evidencia válida. Dicha fiabilidad depende de la seguridad del ciclo de vida completo de la firma, incluyendo las fases de generación, transferencia, verificación, almacenamiento y custodia. Cualquier vulnerabilidad en dicho proceso podría socavar la fiabilidad de la firma digital, haciendo difícil su aplicación como evidencia de no repudio. Desafortunadamente, la tecnología está sujeta a vulnerabilidades, existiendo siempre una probabilidad no nula de ocurrencia de amenazas a su seguridad. A pesar de ello, hasta la fecha no se ha propuesto ningún mecanismo que aborde de manera rigurosa el estudio de la fiabilidad real de la tecnología de firma digital. El principal objetivo de esta tesis doctoral es mejorar la fiabilidad de las firmas digitales para que éstas puedan actuar como evidencia de no repudio con garantías suficientes

Self-Reliance for the Internet of Things: Blockchains and Deep Learning on Low-Power IoT Devices

The rise of the Internet of Things (IoT) has transformed common embedded devices from isolated objects to interconnected devices, allowing multiple applications for smart cities, smart logistics, and digital health, to name but a few. These Internet-enabled embedded devices have sensors and actuators interacting in the real world. The IoT interactions produce an enormous amount of data typically stored on cloud services due to the resource limitations of IoT devices. These limitations have made IoT applications highly dependent on cloud services. However, cloud services face several challenges, especially in terms of communication, energy, scalability, and transparency regarding their information storage. In this thesis, we study how to enable the next generation of IoT systems with transaction automation and machine learning capabilities with a reduced reliance on cloud communication. To achieve this, we look into architectures and algorithms for data provenance, automation, and machine learning that are conventionally running on powerful high-end devices. We redesign and tailor these architectures and algorithms to low-power IoT, balancing the computational, energy, and memory requirements.The thesis is divided into three parts:Part I presents an overview of the thesis and states four research questions addressed in later chapters.Part II investigates and demonstrates the feasibility of data provenance and transaction automation with blockchains and smart contracts on IoT devices.Part III investigates and demonstrates the feasibility of deep learning on low-power IoT devices.We provide experimental results for all high-level proposed architectures and methods. Our results show that algorithms of high-end cloud nodes can be tailored to IoT devices, and we quantify the main trade-offs in terms of memory, computation, and energy consumption