Blockchain-Research and Applications最新文献

This paper reports the design, implementation, and experimental phases of the EU H2020 QualiChain pilot “Staffing the Public Sector—The Case of Portugal”. The overall purpose of this pilot is to ensure the authenticity and integrity of the diplomas for all involved stakeholders and therefore to contribute to solving the diploma counterfeiting and/or falsification that is a great threat to the recruitment of qualified personnel. The main innovative aspect of this solution is the integration that is offered between an Academic Management System (the Fenix.edu platform) and a Blockchain (Ethereum) to automatically deploy diplomas. This solution helps the involved stakeholders trust the diplomas provided. The case study involves four different stakeholders and studies, specifically, the increase in their satisfaction in terms of diploma control, diploma veracity, and diploma credibility. The developed system was tested with external participants who were asked to follow a set of guidelines and complete a survey to assess their perceptions. All system interactions were recorded, and the data were analyzed. The results indicated that the participants successfully executed the guidelines and that a perception increase toward diploma control, veracity, and credibility was identified.

In most popular public accessible cryptocurrency systems, the mining pool plays a key role because mining cryptocurrency with the mining pool turns the non-profitable situation into profitable for individual miners. In many recent novel blockchain consensuses, the deep learning training procedure becomes the task for miners to prove their workload. Thus, the computation power of miners will not purely be spent on the hash puzzle. In this way, the hardware and energy will support the blockchain service and deep learning training simultaneously. While the incentive of miners is to earn tokens, individual miners are motivated to join mining pools to become more competitive. In this paper, we are the first to demonstrate a mining pool solution for novel consensuses based on deep learning.

The mining pool manager partitions the full searching space into subspaces, and all miners are scheduled to collaborate on the Neural architecture search (NAS) tasks in the assigned subspace. Experiments demonstrate that the performance of this type of mining pool is more competitive than that of an individual miner. Due to the uncertainty of miners' behaviors, the mining pool manager checks the standard deviation of the performance of high reward miners and prepares backup miners to ensure completion of the tasks of high reward miners.

Nowadays, an increasing number of blockchain architectures provide well-promising protocols for pseudonymous online payments via proposed cryptocurrencies. Most of them suffer from a number of extensibility and scalability issues, as their capacity regarding the number of transactions they are capable of processing per second is limited. Security is also a challenge for this kind of architectures. This paper presents the design and implementation of the Adrestus system, a blockchain-based transaction system with a novel consensus mechanism that is able to tolerate Byzantine faults and is designed to scale without compromising system security. One of the main components of the Adrestus design is a consistent hashing mechanism for the efficient assignment of transactions on parallel regions, called zones, and for solving load balancing problems. We claim that the Adrestus blockchain system scales linearly without compromising system security and achieves its goals without introducing the unnecessary overhead and by eliminating energy and computational waste. Preliminary theoretical simulations and results reflect that Adrestus exceeds the average throughput of the most well-known cryptocurrencies like Bitcoin, and thus, it achieves a higher performance. In this paper, we present this proposed approach along with simulation results and examine the conditions for the proposed fault-tolerant system to meet safety and liveness.

Actual challenges with data in physical infrastructure include: 1) the adversity of its velocity based on access and retrieval, thus integration; 2) its value as its intrinsic quality; 3) its extensive volume with a limited variety in terms of systems; and finally, 4) its veracity, as data can be modified to obtain an economical advantage. Physical infrastructure design based on Agile project management and minimum viable products provides benefits against the traditional waterfall method. Agile supports an early return on investment that promotes circular reinvesting while making the product more adaptable to variable social-economical environments. However, Agile also presents inherent issues due to its iterative approach. Furthermore, project information requires an efficient record of the aims, requirements, and governance not only for the investors, owners, or users but also to keep evidence in future health & safety and other statutory compliance. In order to address these issues, this article presents a Validation and Verification (V&V) model for data marketplaces with a hierarchical process; each data V&V stage provides a layer of data abstraction, value-added services, and authenticity based on Artificial Intelligence (AI). In addition, this proposed solution applies Distributed Ledger Technology (DLT) for a decentralised approach where each user keeps and maintains the data within a ledger. The presented model is validated in real data marketplace applications: 1) live data for the Newcastle Urban Observatory Smart City Project, where data are collected from sensors embedded within the smart city via APIs; 2) static data for University College London (UCL)—Real Estate—PEARL Project, where different project users and stakeholders introduce data into a Project Information Model (PIM).

COVID-19 has changed almost all aspects of our lives. Governments around the world have imposed lockdowns to slow down the transmissions. Fortunately, we have found the vaccine, in fact, a good number of them. However, managing the testing and vaccination process of the total population is a mammoth job. However, there are always delays or data silo problems in multi-organizational work. Therefore, streamlining this process is vital to improve efficiency and save more lives. Because of its effective data sharing mechanism among different entities with a number of security features, blockchain can be an effective tool for different applications in the health sector. Furthermore, blockchain provides a distributed system along with greater privacy, transparency, and authenticity. In this article, we have presented a blockchain-based system that seamlessly integrates testing and vaccination systems, allowing the system to be transparent. The instant verification of any tamper-proof COVID-19 test result has been developed, which will serve as “Test Certificates”. A transparent and efficient vaccination system has also been exhibited and implemented as the “Digital Vaccine Passport” (DVP) system. The infection rate-based prioritization will ensure a transparent and fair vaccination process as well as tackle the distribution issue of the limited amount of vaccine. The comparative review with other existing works is also discussed, highlighting a clear difference from the existing works. Our proposed system is distinctive on the basis of prioritization of vaccines and seamless integration of test certificates and vaccine passports, which will aid in controlling the pandemic situation. This system will also be handy in the case of tackling any future pandemics initially.

Ethereum smart contracts are computer programs that are deployed and executed on the Ethereum blockchain to enforce agreements among untrusting parties. Being the most prominent platform that supports smart contracts, Ethereum has been targeted by many attacks and plagued by security incidents. Consequently, many smart contract vulnerabilities have been discovered in the past decade. To detect and prevent such vulnerabilities, different security analysis tools, including static and dynamic analysis tools, have been created, but their performance decreases drastically when codes to be analyzed are constantly being rewritten. In this paper, we propose Eth2Vec, a machine-learning-based static analysis tool that detects smart contract vulnerabilities. Eth2Vec maintains its robustness against code rewrites; i.e., it can detect vulnerabilities even in rewritten codes. Other machine-learning-based static analysis tools require features, which analysts create manually, as inputs. In contrast, Eth2Vec uses a neural network for language processing to automatically learn the features of vulnerable contracts. In doing so, Eth2Vec can detect vulnerabilities in smart contracts by comparing the similarities between the codes of a target contract and those of the learned contracts. We performed experiments with existing open databases, such as Etherscan, and Eth2Vec was able to outperform a recent model based on support vector machine in terms of well-known metrics, i.e., precision, recall, and F1-score.

This paper designed and implemented a blockchain-based multisignature approach to digitally transform supply chain governance in multi-tier food supply chains, particularly in a geographically dispersed beef supply chain. An exploratory case study was utilised to demonstrate the design, implementation, and evaluation of a blockchain-based multisignature approach that was deployed on the Smart Trade Networks (STN) Proof of Authority (PoA) blockchain system for data collection and validation in a beef supply chain context. The multisignature approach was implemented with a use case to track a shipment of 92 cattle and meat products through key events from farm to food service. The use-case deployment records approximately 6000 data points registered on the STN PoA blockchain system. The real-case deployment illustrates the capability of the blockchain-based multisignature approach to digitally improve beef supply chain governance by enabling whole-of-chain transparency and trustworthy information sharing and supports supply chain professionals to have a better understanding of how to unlock blockchain potential for supply chain transformation.

Energy has always been one of the fundamental elements in the growth of human society. It is crucial that we improve our energy management due to the ever-growing imbalance in demand-supply. The new wave in the energy sector is characterized by the three D's of decarbonization, decentralization, and digitalization. For a sustainable life, it is necessary that energy is tapped from alternative sources that are renewable to leave a minimal carbon footprint. To integrate different sources with the main power grid, we require two-way communication among them. This makes it indispensable that consumers are empowered to protect their privacy and make them the sole owners of their data. A good access control scheme would ensure security of data, and an efficient trading platform would ensure judicious use of the resources. Here, we propose a framework URJA with an access control scheme and an energy trading platform based on blockchain for a smart grid. The locally available renewable sources of energy are connected to the grid such that demand-supply is managed effectively without loss of efficiency and privacy. A customized consensus scheme based on trust ensures a quick operation in real-time.

The demand for electricity is increasing exponentially day by day, especially with the arrival of electric vehicles. In the smart community neighborhood project, electricity should be produced at the household or community level and sold or bought according to the demands. Since the actors can produce, sell, and buy according to the demands, thus the name prosumers. ICT solutions can contribute to this in several ways, such as machine learning for analyzing the household data for customer demand and peak hours for the usage of electricity, blockchain as a trustworthy platform for selling or buying, data hub, and ensuring data security and privacy of prosumers. TOTEM: Token for controlled computation is a framework that allows users to analyze the data without moving the data from the data owner's environment. It also ensures the data security and privacy of the data. Here, in this article, we will show the importance of the TOTEM architecture in the EnergiX project and how the extended version of TOTEM can be efficiently merged with the demands of the current and similar projects.