BlockPKI: An Automated, Resilient, and Transparent Public-Key Infrastructure

This paper describes BlockPKI, a blockchain-based public-key infrastructure that enables an automated, resilient, and transparent issuance of digital certificates. Our goal is to address several shortcomings of the current TLS infrastructure and its proposed extensions. In particular, we aim at reducing the power of individual certification authorities and make their actions publicly visible and accountable, without introducing yet another trusted third party. To demonstrate the benefits and practicality of our system, we present evaluation results and describe our prototype implementation.Comment: Workshop on Blockchain and Sharing Economy Application

Federated Robust Embedded Systems: Concepts and Challenges

The development within the area of embedded systems (ESs) is moving rapidly, not least due to falling costs of computation and communication equipment. It is believed that increased communication opportunities will lead to the future ESs no longer being parts of isolated products, but rather parts of larger communities or federations of ESs, within which information is exchanged for the benefit of all participants. This vision is asserted by a number of interrelated research topics, such as the internet of things, cyber-physical systems, systems of systems, and multi-agent systems. In this work, the focus is primarily on ESs, with their specific real-time and safety requirements. While the vision of interconnected ESs is quite promising, it also brings great challenges to the development of future systems in an efficient, safe, and reliable way. In this work, a pre-study has been carried out in order to gain a better understanding about common concepts and challenges that naturally arise in federations of ESs. The work was organized around a series of workshops, with contributions from both academic participants and industrial partners with a strong experience in ES development. During the workshops, a portfolio of possible ES federation scenarios was collected, and a number of application examples were discussed more thoroughly on different abstraction levels, starting from screening the nature of interactions on the federation level and proceeding down to the implementation details within each ES. These discussions led to a better understanding of what can be expected in the future federated ESs. In this report, the discussed applications are summarized, together with their characteristics, challenges, and necessary solution elements, providing a ground for the future research within the area of communicating ESs

Decentralized Access Control in Networked File Systems

The Internet enables global sharing of data across organizational boundaries. Traditional access control mechanisms are intended for one or a small number of machines under common administrative control, and rely on maintaining a centralized database of user identities. They fail to scale to a large user base distributed across multiple organizations. This survey provides a taxonomy of decentralized access control mechanisms intended for large scale, in both administrative domains and users. We identify essential properties of such access control mechanisms. We analyze popular networked file systems in the context of our taxonomy

A Decentralised Digital Identity Architecture

Current architectures to validate, certify, and manage identity are based on centralised, top-down approaches that rely on trusted authorities and third-party operators. We approach the problem of digital identity starting from a human rights perspective, with a primary focus on identity systems in the developed world. We assert that individual persons must be allowed to manage their personal information in a multitude of different ways in different contexts and that to do so, each individual must be able to create multiple unrelated identities. Therefore, we first define a set of fundamental constraints that digital identity systems must satisfy to preserve and promote privacy as required for individual autonomy. With these constraints in mind, we then propose a decentralised, standards-based approach, using a combination of distributed ledger technology and thoughtful regulation, to facilitate many-to-many relationships among providers of key services. Our proposal for digital identity differs from others in its approach to trust in that we do not seek to bind credentials to each other or to a mutually trusted authority to achieve strong non-transferability. Because the system does not implicitly encourage its users to maintain a single aggregated identity that can potentially be constrained or reconstructed against their interests, individuals and organisations are free to embrace the system and share in its benefits.Comment: 30 pages, 10 figures, 3 table

Supply chain traceability using blockchain

Mestrado em Gestão MBARastreabilidade é a capacidade de rastrear a origem, a história e a distribuição de produtos numa cadeia logística. Para implementar rastreabilidade completa, é crucial estabelecer uma cadeia de custódia, normalmente definida como uma sequência de procedimentos que valida a propriedade e o controle de produtos ao longo da cadeia de logística. No mercado atual globalizado, as cadeias de logística podem abranger um grande número de países e fronteiras e exigir a interoperabilidade de numerosas organizações. Esta vastidão e complexidade impacta a competitividade dos negócios e dificulta a segurança, e a transparência da cadeia de logística. A implementação da rastreabilidade é fundamental para que as organizações possam posteriormente demonstrar a rastreabilidade, proveniência e integridade e conformidade do produto. A tecnologia Blockchain, com os seus atributos de descentralização, transparência e imutabilidade, tem sido apontada como destinada a revolucionar vários setores, com aplicação ao gerenciamento de cadeias de logística. O presente estudo começa pela revisão da literatura publicada para encontrar aspetos que influenciam o problema e segue a Metodologia de Pesquisa de Projeto para analisar os requisitos e propor uma solução para um sistema de gestão de cadeia de logística com melhor rastreabilidade. Os resultados da tese são artefactos de arquitetura, incluindo um contracto inteligente para Ethereum e um sistema de autenticação baseado em certificados, que permitem a implementação de um sistema de cadeia de logística suportado em Ethereum Blockchain que providencia aos seus utilizadores e ao consumidor final, as funcionalidades de proveniência, rastreabilidade e cadeia de custódia.Traceability is the ability to trace the origin, processing history, and the distribution of products in a Supply chain. In order to implement a complete traceability system, it is crucial to establish a chain of custody. Chain of Custody is typically defined as a sequence of procedures that validates the ownership and control of products along the supply chain. In the current global marketplace supply chains can span a huge number of countries and require interoperation of a multitude of organizations. This vastness of supply chains impacts business competitiveness since it adds complexity and can difficult securing traceability, chain of custody and transparency. In this work it is proposed a complete approach for organizations to be able to demonstrate traceability, provenance (proof of origin) and product integrity and compliance. Blockchain technology with its attributes of decentralization, transparency and immutability has been touted to revolutionize several industries, and most recently has been proposed for supply chain management (SCM). The present study reviews the published literature to find the aspects that influence the problem and then follows the Design Science Research Methodology to analyze the requirements and propose a solution to a more complete traceability in SCMs. The results of this thesis were architectural artifacts, including an Ethereum SC (Smart Contract) and a certificate-based authentication system. These deliverables would allow implementation of a supply chain system over the Ethereum Blockchain that can provide decentralized and trustful assurance of the provenance, chain of custody and traceability functionalities for the participants and consumers.info:eu-repo/semantics/publishedVersio

Performance Analysis of Blockchain Platforms

Blockchain technologies have drawn massive attention to the world these past few years mostly because of the burst of cryptocurrencies like Bitcoin, Etherium, Ripple and many others. A Blockchain, also known as distributed ledger technology, has demonstrated huge potential in saving time and costs. This open-source technology which generates a decentralized public ledger of transactions is widely appreciated for ensuring a high level of privacy through encryption and thus sharing the transaction details only amongst the participants involved in the transactions. The Blockchain is used not only for cryptocurrency but also by various companies to meet their business ends, such as efficient management of supply chains and logistics. The rise and fall of numerous crypto-currencies based on blockchain technology have generated debate among tech-giants and regulatory bodies. There are various groups which are working on standardizing the blockchain technology. At the same time, numerous groups are actively working, developing and fine-tuning their own blockchain platforms. Platforms such as etherium, hyperledger, parity, etc. have their own pros and cons. This research is focused on the performance analysis of blockchain platforms which gives a comparative understanding of these platforms