Valentina Gatteschi, F. Lamberti, C. Demartini
et al.
Blockchain is receiving increasing attention from academy and industry, since it is considered a breakthrough technology that could bring huge benefits to many different sectors. In 2017, Gartner positioned blockchain close to the peak of inflated expectations, acknowledging the enthusiasm for this technology that is now largely discussed by media. In this scenario, the risk to adopt it in the wake of enthusiasm, without objectively judging its actual added value is rather high. Insurance is one the sectors that, among others, started to carefully investigate the possibilities of blockchain. For this specific sector, however, the hype cycle shows that the technology is still in the innovation trigger phase, meaning that the spectrum of possible applications has not been fully explored yet. Insurers, as with many other companies not necessarily active only in the financial sector, are currently requested to make a hard decision, that is, whether to adopt blockchain or not, and they will only know if they were right in 3–5 years. The objective of this paper is to support actors involved in this decision process by illustrating what a blockchain is, analyzing its advantages and disadvantages, as well as discussing several use cases taken from the insurance sector, which could easily be extended to other domains.
The rapid growth of Internet of Vehicles (IoV) has brought huge challenges for large data storage, intelligent management, and information security for the entire system. The traditional centralized management approach for IoV faces the difficulty in dealing with real-time response. The blockchain, as an effective technology for decentralized distributed storage and security management, has already showed great advantages in its application of Bitcoin. In this paper, we investigate how the blockchain technology could be extended to the application of vehicle networking, especially with the consideration of the distributed and secure storage of big data. We define several types of nodes such as vehicle and roadside for vehicle networks and form several sub-blockchain networks. In this paper, we present a model of the outward transmission of vehicle blockchain data, and then give detail theoretical analysis and numerical results. This paper has shown the potential to guide the application of blockchain for future vehicle networking.
Blockchain and AI are promising techniques for next-generation wireless networks. Blockchain can establish a secure and decentralized resource sharing environment. AI can be explored to solve problems with uncertain, time-variant, and complex features. Both of these techniques have recently seen a surge in interest. The integration of these two techniques can further enhance the performance of wireless networks. In this article, we first propose a secure and intelligent architecture for next-generation wireless networks by integrating AI and blockchain into wireless networks to enable flexible and secure resource sharing. Then we propose a blockchain empowered content caching problem to maximize system utility, and develop a new caching scheme by utilizing deep reinforcement learning. Numerical results demonstrate the effectiveness of the proposed scheme.
Food security can benefit from the technology's transparency, relatively low transaction costs and instantaneous applications. A blockchain is a distributed database of records in the form of encrypted blocks, or a public ledger of all transactions or digital events that have been executed and shared among participating parties and can be verified at any time in the future. Generally, the robust and decentralized functionality of the blockchain is used for global financial systems, but it can easily be expanded to contracts and operations such as tracking of the global supply chain. In the precision agriculture context, Information and Communications Technology can be further implemented with a blockchain infrastructure to enable new farm systems and e-agriculture schemes. The purpose of this review is to show a panorama of the scientific studies (enriched by a terms mapping analysis) on the use of blockchain in the agri-food sector, from both an entirely computational and an applicative point of view. As evidenced by the network analysis, the reviewed studies mainly focused on software aspects (e.g., the architecture and smart contracts). However, some aspects regarding the different blockchain knots (computers always connected to the blockchain network) having the role to store and distribute an updated copy of each block in a food supply-chain, result of crucial importance. These technologies appear very promising and rich of great potential showing a good flexibility for applications in several sectors but still immature and hard to apply due to their complexity. This article is protected by copyright. All rights reserved.
Shubhani Aggarwal, Rajat Chaudhary, G. Aujla
et al.
Abstract Since the success of Bitcoin, there have been increased focus of studying the application of blockchain in a broad range of applications, such as in solutions facilitating identity privacy and transaction security using a decentralized architecture via different consensus mechanisms (e.g. proof-of-work) between different geo-located IoT devices/nodes in our increasingly digitalized society (e.g. smart city). In this paper, we survey the usage of blockchain technology for smart communities, focusing on key components of the blockchain applications. We also study the various process models used in the execution of secure transactions. Specifically, we present a detailed taxonomy on the applications, process models used, and communication infrastructure support needed to execute various applications.
Abstract A secure digital evidence system should ensure that evidence cannot be tampered with and that private information cannot be leaked. Blockchain, a distributed tamper-resistant and privacy-preserving ledger, provides a promising solution for decentralized secure digital evidence systems. However, due to the huge number of digital evidences and the contradiction between the traceability and the privacy of evidence, blockchain faces big data and privacy challenges. To solve the above issues, we propose a secure digital evidence framework using blockchain (Block-DEF) with a loose coupling structure in which the evidence and the evidence information are maintained separately. Only the evidence information is stored in the blockchain, and the evidence is stored on a trusted storage platform. To avoid blockchain bloat, a lightweight blockchain combining a mixed block structure with an optimized name-based practical byzantine fault tolerance consensus mechanism is proposed. To support the traceability and the privacy of evidence, the multi-signature technique is adopted for evidence submission and retrieval. The analytical and experimental results show that Block-DEF is a scalable framework, it guarantees the integrity and validity of evidence, and balances privacy and traceability well.
Blockchain technology is destined to revolutionise supply chain processes. At the same time, governmental and regulatory policies are forcing firms to adjust their supply chains in response to environmental concerns. The objective of this study is therefore to develop a distributed ledger-based blockchain approach for monitoring supply chain performance and optimising both emission levels and operational costs in a synchronised fashion, producing a better outcome for the supply chain. We propose the blockchain approach for different production allocation problems within a multi-echelon supply chain (MESC) under a carbon taxation policy. As such, we couple recent advances in digitalisation of operations with increasingly stringent regulatory environmental policies. Specifically, with lead time considerations under emission rate constraints (imposed by a carbon taxation policy), we simultaneously consider the production, distribution and inventory control decisions in a production allocation-based MESC problem. The problem is then formulated as a Mixed Integer Non-Linear Programming (MINLP) model. We show that the distributed ledger-based blockchain approach minimises both total cost and carbon emissions. We then validate the feasibility of the proposed approach by comparing the results with a non-dominated sorting genetic algorithm (NSGA-II). The findings provide support for policymakers and supply chain executives alike.
Blockchain has been regarded as a promising technology for IoT, since it provides significant solutions for decentralized networks that can address trust and security concerns, high maintenance cost problems, and so on. The decentralization provided by blockchain can be largely attributed to the use of a consensus mechanism, which enables peer-to-peer trading in a distributed manner without the involvement of any third party. This article starts by introducing the basic concept of blockchain and illustrating why a consensus mechanism plays an indispensable role in a blockchain enabled IoT system. Then we discuss the main ideas of two famous consensus mechanisms, PoW and PoS, and list their limitations in IoT. Next, two mainstream DAG based consensus mechanisms, the Tangle and Hashgraph, are reviewed to show why DAG consensus is more suitable for IoT system than PoW and PoS. Potential issues and challenges of DAG based consensus mechanisms to be addressed in the future are discussed in the last section.
In recent years, Blockchain has attracted tremendous attention due to its salient features including auditability, immutability, security, and anonymity. Resulting from these salient features, blockchain has been applied in multiple non-monetary applications including the Internet of Things (IoT). However, blockchain is computationally expensive, has limited scalability and incurs significant bandwidth overheads and delays which are not suited for most IoT applications. In this paper, we propose a Lightweight Scalable blockchain (LSB) that is optimized for IoT requirements while also providing end-to-end security. Our blockchain instantiation achieves decentralization by forming an overlay network where high resource devices jointly manage the blockchain. The overlay is organized as distinct clusters to reduce overheads and the cluster heads are responsible for managing the public blockchain. We propose a Distributed Time-based Consensus algorithm (DTC) which reduces the mining processing overhead and delay. Distributed trust approach is employed by the cluster heads to progressively reduce the processing overhead for verifying new blocks. LSB incorporates a Distributed Throughput Management (DTM) algorithm which ensures that the blockchain throughput does not significantly deviate from the cumulative transaction load in the network. We explore our approach in a smart home setting as a representative example for broader IoT applications. Qualitative arguments demonstrate that our approach is resilient to several security attacks. Extensive simulations show that packet overhead and delay are decreased and blockchain scalability is increased compared to relevant baselines.
Abstract Although a number of studies focus on using the blockchain technology (BT) in various application aspects, there is no comprehensive survey on the blockchain applications in maritime shipping supply chain. To fill this gap, we conduct a comprehensive blockchain applications and future improvements survey, and empirically evaluate its effects on intention to use. The results suggested that customs clearance and management, digitalizing and easing paperwork, standardization and platform development dimensions positively affected intention to use. In particular, this paper gives the maritime shipping blockchain-based digitalization also points out the future improvement directions in the blockchain technology.
Abstract Blockchain technology holds immense potential for industries and services by executing transactions in a verifiable and permanent way. It operates as an open distributed ledger that can record transactions between two parties. However, the adoption and implementation of blockchain technologies in various industries and services is a challenging task. In this study, we develop a framework for investigating barriers to the adoption and successful implementation of blockchains across different industries and services, using DEMATEL technique. We identify these barriers with the help of extant literature and experts’ opinions and further classify them into ten broad categories. Then, we establish the causal relationships among those barriers and rank them based on their degree of prominence and relationships. We find that challenges in scalability and market-based risks are the most influencing barriers. Whereas high sustainability costs and poor economic behavior are the most influenced barriers during successful blockchain adoption. Finally, we perform a series of sensitivity analysis to test the robustness and generalizability of our proposed framework. Findings from our study will be beneficial for managers and help to eliminate the major barriers in the efficient implementation of blockchain technologies in their organizations.
Originally conceived as a mechanism to enable a trustless cryptocurrency—Bitcoin, blockchain has since unbound itself from its original purpose as an increasing number of industries and stakeholders’ eye the technology as an attractive alternative to solve existing business solutions as well as disrupt mature industries. This paper presents a systematic literature review of the blockchain technology, tracking its increase in popularity in relation to similar technologies, such as cryptocurrencies and Bitcoin. The objective of this paper is to identify the current standing of the blockchain technology within the literature while also identifying the major fields of study and areas of application for which blockchain offers a valuable solution. This paper finds that unique features to the blockchain, such as privacy, security, anonymity, decentralization, and immutability, provide valuable benefits to various fields and subjects. This paper also finds that exploring the application of blockchain has only begun with some limited studies in areas, such as the Internet of Things, energy, finance, healthcare, and government, that also stand to benefit disproportionately from its implementation.
The potential of blockchain has been extensively discussed in the literature and media mainly in finance and payment industry. One relatively recent trend is at the enterprise-level, where blockchain serves as the infrastructure for internet security and immutability. Emerging application domains include Industry 4.0 and Industrial Internet of Things (IIoT). Therefore, in this paper, we comprehensively review existing blockchain applications in Industry 4.0 and IIoT settings. Specifically, we present the current research trends in each of the related industrial sectors, as well as successful commercial implementations of blockchain in these relevant sectors. We also discuss industry-specific challenges for the implementation of blockchain in each sector. Further, we present currently open issues in the adoption of the blockchain technology in Industry 4.0 and discuss newer application areas. We hope that our findings pave the way for empowering and facilitating research in this domain, and assist decision-makers in their blockchain adoption and investment in Industry 4.0 and IIoT space.
Blockchain is a distributed and decentralized ledger for recording transactions. It is maintained and shared among the participating nodes by utilizing cryptographic primitives. A consensus protocol ensures that all nodes agree on a unique order in which records are appended. However, current blockchain solutions are facing scalability issues. Many methods, such as Off-chain and Directed Acyclic Graph (DAG) solutions, have been proposed to address the issue. However, they have inherent drawbacks, e.g., forming parasite chains. Performance, such as throughput and latency, is also important to a blockchain system. Sharding has emerged as a good candidate that can overcome both the scalability and performance problems in blockchain. To date, there is no systematic work that analyzes the sharding protocols. To bridge this gap, this paper provides a systematic and comprehensive review on blockchain sharding techniques. We first present a general design flow of sharding protocols and then discuss key design challenges. For each challenge, we analyze and compare the techniques in state-of-the-art solutions. Finally, we discuss several potential research directions in blockchain sharding.
Faris Ali, Khairy Elghaish, Sepehr Abrishami
et al.
Abstract Integrated project delivery (IPD) in the architecture, engineering and construction (AEC) industry relies on risk/reward sharing and deferral of parties' profit payments until all project activities are completed. A decentralised, automated and secured financial platform is needed to enable all parties to control and track financial transactions, with no unauthorised changes allowed. The new technology, blockchain, enables data to be recorded, has no network participant with dominant power and manages data using specific functions, in line with smart contracts. The present study is the first to develop a framework proposing blockchain technology utilisation in IPD projects. The framework would enable core project team members to automatically execute all financial transactions, through coding the three main transactions of IPD projects: reimbursed costs, profit and cost saving, as functions of the IPD smart contract. To demonstrate the proposed framework's applicability, a “proof of concept” is developed and validated through an IPD case project. The practicality of the built-up hyperledger network (IBM® Blockchain Cloud Beta 2) and the advantages of the proposed smart contract functions are examined. The user-friendliness of the proposed financial system and its efficiency in automating all transactions are demonstrated. No deficiency is found in the blockchain network components. The study's findings, applied in a favourable external context, would facilitate IPD adoption and use across the AEC industry by providing a workable solution to existing financial barriers. The findings extend the horizon for further research on exploring blockchain's capabilities to solve comparable deficiencies to those affecting the AEC industry.
Blockchain – also known as distributed ledger – technology is set to revolutionise data and business process management and transactions. Blockchain adoption, pioneered initially as a financial tec...
Abstract Despite the rapid development of cloud computing for many years, data security and trusted computing are still the main challenges in current cloud computing applications. In order to solve this problem, many scholars have carried out a lot of research on this, and proposed many models including data integrity test and secure multi-party calculation. However, most of these solutions face problems such as excessive computational complexity or lack of scalability. This paper studies the use of blockchain techniques to improve this situation. Blockchain is a decentralized new distributed computing paradigm. Applying blockchain technology to cloud computing, using the security mechanism of the former to improve the performance of the latter’s secure storage and secure computing is a promising research topic. In this paper, the distributed virtual machine agent model is deployed in the cloud by using mobile agent technology. The virtual machine agent enables multi-tenants to cooperate with each other to ensure data trust verification. The tasks of reliable data storage, monitoring and verification are completed by virtual machine agent mechanism. This is also a necessary condition for building a blockchain integrity protection mechanism. The blockchain-based integrity protection framework is built by the virtual machine proxy model, and the unique hash value corresponding to the file generated by the Merkel hash tree is used to monitor the data change by means of the smart contract on the blockchain, and the data is owned in time. The user issues a warning message for data tampering; in addition, a “block-and-response” mode is used to construct a blockchain-based cloud data integrity verification scheme.
The Vehicle-to-Grid (V2G) network is, where the battery-powered vehicles provide energy to the power grid, is highly emerging. A robust, scalable, and cost-optimal mechanism that can support the increasing number of transactions in a V2G network is required. Existing studies use traditional blockchain as to achieve this requirement. Blockchain-enabled V2G networks require a high computation power and are not suitable for micro-transactions due to the mining reward being higher than the transaction value itself. Moreover, the transaction throughput in the generic blockchain is too low to support the increasing number of frequent transactions in V2G networks. To address these challenges, in this paper, a lightweight blockchain-based protocol called Directed Acyclic Graph-based V2G network (DV2G) is proposed. Here blockchain refers to any Distributed Ledger Technology (DLT) and not just the bitcoin chain of blocks. A tangle data structure is used to record the transactions in the network in a secure and scalable manner. A game theory model is used to perform negotiation between the grid and vehicles at an optimized cost. The proposed model does not require the heavy computation associated to the addition of the transactions to the data structure and does not require any fees to post the transaction. The proposed model is shown to be highly scalable and supports the micro-transactions required in V2G networks.
Problem definition: For many supply chains, deep-tier suppliers, due to their small size and lack of access to capital, are most vulnerable to disruptions. We study the use of advance payment (AP) as a financing instrument in a multitier supply chain to mitigate the supply disruption risk in a traditional system (with limited visibility) and a blockchain-enabled system (with perfect visibility). The main goal of this paper is to shed light on how blockchain adoption impacts agents’ operational and financial decisions as well as profit levels in a multitier supply chain. Academic/practical relevance: Traditionally, because of the limited visibility in the deep tiers, powerful downstream manufacturers’ financing schemes offered to their immediate upstream suppliers are not effective in instilling capital into the deep tiers. Advancements in blockchain technology improve the supply chain visibility and enable the manufacturer to better devise deep-tier financing to improve supply chain resilience. Methodology: We develop a three-tier supply chain model and take a game-theoretic approach to compare how blockchain-enabled deep-tier financing schemes affect a financially constrained supply chain’s optimal risk-mitigation and financial strategies. Results: We find that although improved visibility via blockchain adoption can help the manufacturer make informed supply chain financing decisions, whether it can benefit all supply chain members depends on the financing schemes in use. Blockchain-enabled delegate financing increases risk-mitigation investments and benefits all three tiers of the supply chain only when the tier 2 supplier is severely capital-constrained with the working capital below a threshold. Because delegate financing endows the intermediary tier 1 supplier with leverage over the manufacturer, the inefficiency inhibits an all-win outcome when the tier 2 supplier is not severely capital-constrained. Blockchain-enabled cross-tier direct financing exhibits a compelling performance as it always leads to win-win-win outcomes (and is thus ubiquitously implementable) regardless of the suppliers’ working capital profile. Managerial implications: Our insights help firms assess opportunities and challenges associated with enhancing supply chain visibility via blockchain adoption.