121 research outputs found

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

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    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

    Modeling of Distributed Ledger Deployment View

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    The Distributed Ledger Technology (DLT) is a peer-to-peer model of sharing data among collaborating parties in a decentralized manner. An example of DLT is a blockchain where data form blocks in an append-only chain. Software architecture description usually comprises multiple views. The paper concentrates on the Deployment view of the DLT solution within the 1+5 architectural views model. The authors have proposed Unified Modeling Language (UML) extensibility mechanisms to describe the needed additional semantic notation to model deployment details. The paper covers both the network and node levels. The proposed stereotypes and tagged values have enriched the UML Deployment diagram. We have gathered those modeling elements in dedicated UML Profile for Distributed Ledger Deployment. We have applied the profile to model the Deployment view of a renewable energy management system that uses the R3Cordaframework. The system records information about inbound and outbound energy to/from a renewable energy grid

    Modeling of Distributed Ledger Deployment View

    Get PDF
    The Distributed Ledger Technology (DLT) is a peer-to-peer model of sharing data among collaborating parties in a decentralized manner. An example of DLT is a blockchain where data form blocks in an append-only chain. Software architecture description usually comprises multiple views. The paper concentrates on the Deployment view of the DLT solution within the 1+5 architectural views model. The authors have proposed Unified Modeling Language (UML) extensibility mechanisms to describe the needed additional semantic notation to model deployment details. The paper covers both the network and node levels. The proposed stereotypes and tagged values have enriched the UML Deployment diagram. We have gathered those modeling elements in dedicated UML Profile for Distributed Ledger Deployment. We have applied the profile to model the Deployment view of a renewable energy management system that uses the R3Cordaframework. The system records information about inbound and outbound energy to/from a renewable energy grid

    PDFS: Practical Data Feed Service for Smart Contracts

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    Smart contracts are a new paradigm that emerged with the rise of the blockchain technology. They allow untrusting parties to arrange agreements. These agreements are encoded as a programming language code and deployed on a blockchain platform, where all participants execute them and maintain their state. Smart contracts are promising since they are automated and decentralized, thus limiting the involvement of third trusted parties, and can contain monetary transfers. Due to these features, many people believe that smart contracts will revolutionize the way we think of distributed applications, information sharing, financial services, and infrastructures. To release the potential of smart contracts, it is necessary to connect the contracts with the outside world, such that they can understand and use information from other infrastructures. For instance, smart contracts would greatly benefit when they have access to web content. However, there are many challenges associated with realizing such a system, and despite the existence of many proposals, no solution is secure, provides easily-parsable data, introduces small overheads, and is easy to deploy. In this paper we propose PDFS, a practical system for data feeds that combines the advantages of the previous schemes and introduces new functionalities. PDFS extends content providers by including new features for data transparency and consistency validations. This combination provides multiple benefits like content which is easy to parse and efficient authenticity verification without breaking natural trust chains. PDFS keeps content providers auditable, mitigates their malicious activities (like data modification or censorship), and allows them to create a new business model. We show how PDFS is integrated with existing web services, report on a PDFS implementation and present results from conducted case studies and experiments.Comment: Blockchain; Smart Contracts; Data Authentication; Ethereu

    The Evaluation of Notary Studies Globally: Bibliometric Analysis

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    This study aims to investigate research trends on notarial topics in published documents globally, including identifying the position of Indonesian research in this context and issues that require further exploration in this discipline. This research method involves collecting data on notary publications from various indexed journal sources in the Scopus database. Scopus was chosen because it is a popular and trusted indexer. This data was then analyzed bibliometrically to identify trends in the number of publications, the most prolific authors, and documents frequently cited in the notary field, including the research topics discussed. In addition, the position of Indonesian research in international databases is also evaluated. The research findings show that notarization is an important and fast-growing field in the global legal system. Notarial publications have steadily increased in recent years, reflecting the growing interest in the discipline globally. This research also reveals that Indonesia has contributed many publications in notary affairs, but there is still potential for further development. Topics such as digital notarization and smart contracts stand out as areas that require further exploration. This indicates the importance of adapting to technological developments and changes in legal practice. Thus, this research provides a deeper understanding of the urgency and position of the notary in navigating an increasingly complex and globally connected legal era

    Keeping Authorities "Honest or Bust" with Decentralized Witness Cosigning

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    The secret keys of critical network authorities - such as time, name, certificate, and software update services - represent high-value targets for hackers, criminals, and spy agencies wishing to use these keys secretly to compromise other hosts. To protect authorities and their clients proactively from undetected exploits and misuse, we introduce CoSi, a scalable witness cosigning protocol ensuring that every authoritative statement is validated and publicly logged by a diverse group of witnesses before any client will accept it. A statement S collectively signed by W witnesses assures clients that S has been seen, and not immediately found erroneous, by those W observers. Even if S is compromised in a fashion not readily detectable by the witnesses, CoSi still guarantees S's exposure to public scrutiny, forcing secrecy-minded attackers to risk that the compromise will soon be detected by one of the W witnesses. Because clients can verify collective signatures efficiently without communication, CoSi protects clients' privacy, and offers the first transparency mechanism effective against persistent man-in-the-middle attackers who control a victim's Internet access, the authority's secret key, and several witnesses' secret keys. CoSi builds on existing cryptographic multisignature methods, scaling them to support thousands of witnesses via signature aggregation over efficient communication trees. A working prototype demonstrates CoSi in the context of timestamping and logging authorities, enabling groups of over 8,000 distributed witnesses to cosign authoritative statements in under two seconds.Comment: 20 pages, 7 figure

    Blockchain in maritime cybersecurity

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    Blockchain technologies can be used for many different purposes from handling large amounts of data to creating better solutions for privacy protection, user authentication and a tamper proof ledger which lead to growing interest among industries. Smart contracts, fog nodes and different consensus methods create a scalable environment to secure multi-party connections with equal trust of participanting nodes’ identity. Different blockchains have multiple options for methodologies to use in different environments. This thesis has focused on Ethereum based open-source solutions that fit the remote pilotage environment the best. Autonomous vehicular networks and remote operatable devices have been a popular research topic in the last few years. Remote pilotage in maritime environment is persumed to reach its full potential with fully autonomous vessels in ten years which makes the topic interesting for all researchers. However cybersecurity in these environments is especially important because incidents can lead to financial loss, reputational damage, loss of customer and industry trust and environmental damage. These complex environments also have multiple attack vectors because of the systems wireless nature. Denial-of-service (DoS), man-in-the-middle (MITM), message or executable code injection, authentication tampering and GPS spoofing are one of the most usual attacks against large IoT systems. This is why blockchain can be used for creating a tamper proof environment with no single point-of-failure. After extensive research about best performing blockchain technologies Ethereum seemed the most preferable for decentralised maritime environment. In comparison to most of 2021 blockchain technologies that have focused on financial industries and cryptocurrencies, Ethereum has focused on decentralizing applications within many different industries. This thesis provides three Ethereum based blockchain protocol solutions and one operating system for these protocols. All have different features that add to the base blockchain technology but after extensive comparison two of these protocols perform better in means of concurrency and privacy. Hyperledger Fabric and Quorum provide many ways of tackling privacy, concurrency and parallel execution issues with consistent high throughput levels. However Hyperledger Fabric has far better throughput and concurrency management. This makes the solution of Firefly operating system with Hyperledger Fabric blockchain protocol the most preferable solution in complex remote pilotage fairway environment

    Exploração de algoritmos de consenso no Quorum

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    As blockchain technology matures, more industries are becoming interested in evaluating if the technology can answer their needs for decentralized systems that guarantee data immutability and traceability. Quorum is a blockchain platform that accommodates enterprise use-cases by extending Ethereum to support private transactions and a higher transaction throughput. To achieve this, Quorum replaced Ethereum’s proof-of-stake consensus mechanism with proof-of-authority ones, supporting four different algorithms: Raft, Clique, IBFT 1.0, and QBFT. This work explores Quorum’s consensus algorithms and how they affect performance and fault-tolerance, in order to assess the best use cases for each and what should drive their choice. A GoQuorum network was set up, and benchmarks were run against this system under different scenarios while only changing the consensus algorithm for each scenario. Results showed that Raft is the most performant consensus algorithm in Quorum in both private and public transactions. Additionally, QBFT achieved the same performance as IBFT, and Clique was the worst performer across the board, particularly due to having high resource-usage. Regarding fault-tolerance, it was found that bringing validator nodes down at random, when the network has high-availability, had no impact on networks under any of the consensus algorithms.Com blockchain a entrar numa fase de maturidade, cada vez mais indústrias procuram avaliar se esta tecnologia responde às suas necessidades de sistemas distribuídos que garantam a imutabilidade e rastreabilidade dos seus dados. Quorum é uma plataforma blockchain que procura acomodar os casos de uso destas empresas ao extender Ethereum para suportar transações privadas e um maior número de transações por segundo. Para esse efeito, o Quorum substituiu o mecanismo de consenso proof-ofstake do Ethereum por um mecanismo de proof-of-authority, onde quatro algoritmos são suportados: Raft, Clique, IBFT 1.0, e QBFT. Este trabalho explora os algoritmos de consenso suportados pelo Quorum de modo a determinar como estes afetam o desempenho e tolerância a falhas das redes, e consequentemente perceber os melhores casos de uso para estes algoritmos e que fatores ter em conta aquando a sua escolha. Foi criada uma rede de GoQuorum, e vários testes de desempenho foram corridos contra a rede sob diferentes cenários, onde para cada cenário a única variável foi o algoritmo de consenso. Os resultados mostraram que o Raft foi o algoritmo de consenso com melhor desempenho, tanto em transações públicas como privadas. Adicionalmente, o QBFT e o IBFT atingiram o mesmo desempenho, e o Clique o pior de todos, particularmente pelo seu alto uso de recursos do sistema. Quanto a tolerância a falhas, foi concluído que trazer nós validadores abaixo aleatoriamente enquanto o sistema está configurado com alta disponibilidade não tem impacto nas redes, independentemente do algoritmo de consenso utilizado
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