Primitives for Contract-based Synchronization

We investigate how contracts can be used to regulate the interaction between processes. To do that, we study a variant of the concurrent constraints calculus presented in [1], featuring primitives for multi-party synchronization via contracts. We proceed in two directions. First, we exploit our primitives to model some contract-based interactions. Then, we discuss how several models for concurrency can be expressed through our primitives. In particular, we encode the pi-calculus and graph rewriting.Comment: In Proceedings ICE 2010, arXiv:1010.530

Why have public key infrastructures failed so far

Abstract Purpose -To overview and discuss the technical, economical, legal, and social reasons why public key infrastructures (PKIs) have failed so far, summarizing the lessons learned, and giving expectations about the future development of the field. Design/methodology/approach -A detailed analysis of the developments in the PKI field, pointing out the achievements so far and the issues that still remain unsolved. Findings -The possible reasons for the failure of PKI technology. Originality/value -Identifies and analyses the problems of PKIs considering the different perspectives, i.e. not only the technical issues but also other issues like the economical, legal, and social issues that have also influenced the failure of PKIs

The Delivery and Evidences Layer

Evidences of delivery are essential for resolving (and avoiding) disputes on delivery of messages, in classical as well as electronic commerce. We present the first rigorous specifications and provably-secure implementation, for a communication layer providing time-stamped evidences for the message delivery process. This improves on existing standards for evidences (‘non-repudiation’) services, based on informal specifications and unproven designs. Our work also improves on the large body of analytical works on tasks related to evidences of delivery, such as certified mail/delivery protocols and fair exchange (of signatures). We improve by addressing practical needs and scenarios, using realistic synchronization and communication assumptions, supporting time-outs and failures, and providing well-defined interface to the higher-layer protocols (application). Furthermore, we use the layered specifications framework, allowing provably-secure use of our protocol, with lower and higher layer protocols, with complete re-use of our analysis (theorems)

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

Towards Provably-Secure Timed E-Commerce: The Trusted Delivery Layer

Certified exchange of messages is an essential mechanism for e-commerce; the timing aspects (timeouts and timestamps) are very important for practical applications. However existing formal methods for security analysis assume simplified completely synchronous or completely asynchronous models, and cannot deal with the timing aspects of these (and other e-commerce) protocols. We present model for realistic, Δ-synchronized adversarial settings. We then present a simple, efficient and provably-secure protocol for certified, time-stamped message delivery, providing precise guarantees of delay and timestamps. Our model and analysis use concrete (rather than asymptotic) notions of security

Fair' Bpel Processes Transaction Using Non-repudiation Protocols

The single most important invention that has completely revolutionized how business transactions are conducted is the internet. The fast paced technological advancement of web services standards and its tools have transformed the world wide web from information sharing platform to an extremely powerful and open ecosystem of e-services that not only delivers the information but also provide decision support, transactions and applications. There is a need for powerful protocols to achieve universal interoperability among web services and to provide a fair and secure and accountable environment. BPEL provides a language for the formal specification of business processes and business interaction protocols. In business transactions Non-repudiation is a serious and troublesome security issue in which any involved party denies having participated in a transaction. In this thesis - we propose and verify novel non-repudiation protocol specification in BPEL. We model non-repudiation protocols in BPEL and analyze those using Petri Nets. We also propose new Non-repudiation protocols for chain-linked business transactions. In a business transaction there may be more then one recipient and different messages to each of them. We therefore also propose protocols for multiple recipients. We show that the proposed protocols meet the security requirements and are terminated when anyone of the transactions fails, without losing fairness. Our proposed protocols fulfill the requirements of security, fairness, protection and timeliness in different scenarios. Computation load of originator and trusted third party are also reduced using these approaches. These protocols are modeled as Color Petri Nets to verify the reliability of the protocols. BPEL processes have been specified using these protocols.Computer Science Departmen

Utilização de algoritmo de consenso para comunicação segura entre drones em FANETS com baixo custo computacional

The development of vehicular networks has found a more fertile scenario with the advancement of ultra-reliable low latency communications (URLLC), deployment of fifth generation (5G) networks worldwide, empowerment of edge computing and adopting “Internet of Things” solutions in smart cities. To guarantee the success of these networks, it is essential to ensure that the communication process is reliable, safe from malicious actions, and that the solution has low computational complexity and energy consumption. Among vehicular networks that can take advantage of these new technologies are FANETs (Flying Ad-Hoc Networks), which can play a critical role in rescue missions and reconnaissance of risk areas. These networks need a solution that guarantees transparency, security and fault tolerance in a decentralised way to function correctly. Therefore, the present work proposes a proof-of-concept solution to ensure crash-fault tolerant communication in emulated heterogeneous Flying Ad-Hoc Networks (FANETs) using the Proof of Elapsed Time (PoET) consensus algorithm.O desenvolvimento de redes veiculares encontrou um cenário mais fértil com o avanço das comunicações ultra-confiáveis de baixa latência (URLLC), implantação de redes de quinta geração (5G) em todo o mundo, capacitação da computação de borda e a adoção da “Internet das Coisas” nas soluções em cidades inteligentes. Para garantir o sucesso dessas redes, é fundamental que o processo de comunicação seja confiável e seguro contra ações maliciosas e que a solução tenha baixa complexidade computacional e consumo de energia. Entre redes veiculares que podem obter proveito dessas novas tecnologias, estão as FANETs (Flying Ad-Hoc Networks), que podem desempenhar papel crítico em missões de salvamento e reconhecimento de áreas de risco. Esta redes necessitam de uma solução que garanta transparência, segurança e tolerância à falhas de forma descentralizada para funcionarem corretamente. Portanto, o presente trabalho propõe uma solução de prova de conceito para garantir comunicação tolerante a falhas em Redes Aéreas Ad-Hoc (FANETs) heterogêneas com baixo custo computacional emuladas, usando o algoritmo de consenso Proof of Elapsed Time (PoET)

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

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