Blockchains

Blockchain technologies have the potential to fundamentally change logistics and supply chain management. By leveraging the capabilities of blockchain technology, businesses can increase efficiency, reduce costs, and improve security and trust in operations. However, there are still difficulties to overcome in terms of uptake and implementation. This article examines the various blockchain technologies applicable in the field of logistics, presents the benefits and limitations of blockchain technologies in this aspect, and offers a summary of the existing technologies used in the logistics sector. According to this, blockchain-based models applicable both to a specific stage of the logistics process (e.g., transportation of goods, materials, and feedstocks; management of warehouse operations; cargo tracking; etc.) and related insurance services have been proposed. The proposed models have been tested in a lab environment on the HyperLedger Fabric platform, and the results show that they are fully functional. Full article

When migrating smart contracts from one blockchain platform to another, there are potential security risks. This is because different blockchain platforms have different environments and characteristics for executing smart contracts. The focus of this paper is to study the security risks associated with the migration of smart contracts from Ethereum to Arbitrum. We collected relevant data and analyzed smart contract migration cases to explore the differences between Ethereum and Arbitrum in areas such as Arbitrum cross-chain messaging, block properties, contract address alias, and gas fees. From the 36 types of smart contract migration cases we identified, we selected four typical types of cases and summarized their security risks. The research shows that smart contracts deployed on Ethereum may face certain potential security risks during migration to Arbitrum, mainly due to issues inherent in public blockchain characteristics, such as outdated off-chain data obtained by the inactive sequencer, logic errors based on time, failed permission checks, and denial of service (DOS) attacks. To mitigate these security risks, we proposed avoidance methods and provided considerations for users and developers to ensure a secure migration process. It is worth noting that this study is the first to conduct an in-depth analysis of the secure migration of smart contracts from Ethereum to Arbitrum. Full article

The integrity of democratic processes relies on secure and reliable election systems, yet achieving this reliability is challenging. This paper introduces the Post-Quantum Secured Multiparty Computed Hierarchical Authoritative Consensus Blockchain (PQMPCHAC-Bchain), a novel e-voting system designed to overcome the limitations of current Biometric Electronic Voting Machine (EVM) systems, which suffer from trust issues due to closed-source designs, cyber vulnerabilities, and regulatory concerns. Our primary objective is to develop a robust, scalable, and secure e-voting framework that enhances transparency and trust in electoral outcomes. Key contributions include integrating hierarchical authorization and access control with a novel consensus mechanism for proper electoral governance. We implement blockchain sharding techniques to improve scalability and propose a multiparty computed token generation system to prevent fraudulent voting and secure voter privacy. Post-quantum cryptography is incorporated to safeguard against potential quantum computing threats, future-proofing the system. Additionally, we enhance authentication through a deep learning-based face verification model for biometric validation. Our performance analysis indicates that the PQMPCHAC-Bchain e-voting system offers a promising solution for secure elections. By addressing critical aspects of security, scalability, and trust, our proposed system aims to advance the field of electronic voting. This research contributes to ongoing efforts to strengthen the integrity of democratic processes through technological innovation. Full article

Blockchain has emerged as a solution for ensuring accurate and truthful environmental variable monitoring needed for the management of pollutants and natural resources. The immutability property of blockchain helps protect the measured data on pollution and natural resources to enable truthful reporting and effective management and control of polluting agents. However, specifics on what to measure, how to use blockchain, and highlighting which blockchain frameworks have been adopted need to be explored to fill the research gaps. Therefore, we review existing works on the use of blockchain for monitoring and managing environmental variables in this paper. Specifically, we examine existing blockchain applications on greenhouse gas emissions, solid and plastic waste, food waste, food security, water usage, and the circular economy and identify what motivates the adoption of blockchain, features sought, used blockchain frameworks and consensus algorithms, and the adopted supporting technologies to complement data sensing and reporting. We conclude the review by identifying practical works that provide implementation details for rapid adoption and remaining challenges that merit future research. Full article

Blockchain technology has revolutionized numerous industries, including that of financial accounting. However, its potential to support environmental, social, and corporate governance (ESG) objectives remains underexplored. This paper addresses this gap by investigating how blockchain’s decentralized and tamper-resistant characteristics can enhance green financial instruments, investment strategies, and climate-related financial disclosures. By leveraging these unique features of blockchain and applying knowledge discovery from data (KDD) methods, we uncover patterns and establish rules that highlight blockchain’s role in promoting transparency, accountability, and sustainability within the financial sector. Through a comprehensive analysis of literature, case studies, and real-world examples, this paper not only presents a balanced perspective on the integration of blockchain into financial accounting but also underscores its transformative potential in advancing ESG initiatives. The use of KDD provides novel insights into the effectiveness and implementation strategies of blockchain for ESG, making this study a pioneering resource for academics, professionals, and policymakers seeking to understand and harness blockchain’s impact on ESG in financial accounting. Full article

Blockchain technology is now an advanced and innovative database technology and the attributes of blockchains are apparent in a variety of industries, especially in the financial industry. One of the most famous blockchain use cases, cryptocurrencies, has provoked much interest in social network users and customers. According to CoinMarketCap’s information, the global crypto market capitalization has reached around USD 2.37 T and there are around 9975 different cryptocurrencies available in the market. Despite the fact that academia and industry have paid much attention towards the blockchain direction, there is not much research on the factors that influence customer acceptability. This paper studies blockchains from a different angle, probing the factors prompting customers to use financial applications that utilize blockchain technology. We established the model and sorted the individual factors of perceived information security, technology awareness and privacy and found that users’ acceptance is significantly affected by information security and technology awareness, while privacy does not significantly influence users. According to the findings, we provide useful insights for application developers, conclude by presenting the limitations of the research and provide guidelines for future research. Full article

Blockchain technology promises transformative potential across diverse sectors, facilitating innovations in areas ranging from finance to healthcare. Despite its many promising applications, several barriers—including scalability challenges, regulatory complexities, and technical hurdles—limit its widespread adoption. This systematic literature review delves into scalability enhancements and explores the legal and regulatory landscapes impacting blockchain deployment in ten key sectors: IoT, healthcare, finance, education, social media, genomics, supply chain, vehicular networks, e-voting, and tourism. These sectors were selected based on their significant engagement with blockchain technology and their prominence in the analyzed literature. We examine key technological advancements such as Layer-2 techniques, sharding, consensus algorithm optimization, and rollups, and discuss their implications for throughput, latency, and compliance with regulatory standards such as the General Data Protection Regulation (GDPR). The review details these technological and regulatory developments and discusses their broader implications for industry and academia, emphasizing the need for interdisciplinary research and innovation. By identifying gaps in current research and suggesting future directions, this study serves as a roadmap for researchers, practitioners, and policymakers to develop secure, scalable, and compliant blockchain systems. Our comprehensive examination provides valuable insights into enhancing the efficiency, security, and regulatory compliance of blockchain technology. Full article

Blockchain Technology (BCT) offers several possible applications in the field of electronic commerce (e-commerce), such as decentralised marketplaces or payments in cryptocurrencies. Even though these applications of BCT have already been explored in the academic literature, a comprehensive collection along the whole e-commerce value chain is still missing. Furthermore, the existing comprehensive reviews are based on the academic literature whilst the evolution and further development of BCT is highly driven by practitioners. Therefore, we aim to understand how and why BCT is used in e-commerce based on a qualitative content analysis of news articles, i.e., we apply scientific methods to content which reports the latest developments in the field. As a result, we describe the multiple application domains of BCT along the e-commerce value chain. Subsequently, we discuss the main underlying principles of BCT usage across all the value chain steps. Full article

Supply chain bottlenecks in port operations lead to significant delays and inefficiencies. Blockchain technology emerges as a viable solution, offering tamper-resistant ledgers, secure transactions, and automation capabilities. While considerable research on developing blockchain-based solutions currently exist, there is a lack of studies that specifically focus on optimizing port document management to speed up supply chain operations. In this paper, a supply-blockchain functional prototype for optimizing port operations using Hyperledger Fabric is introduced. In terms of core functionality, the prototype allows initiation of smart contract corresponding to functions such as creating and editing port-related documents, minimizing manual interventions and enhancing efficiency to reduce port congestion. Furthermore, it provides live tracking of completed events and transactions, facilitating transparency and streamlined oversight. The permissioned nature of Hyperledger Fabric ensures security and robust access controls, aligning well with sensitive port operations. Hyperledger Firefly and its connector framework was used as the middleware to facilitate blockchain integration and various functions of the prototype, while chaincode developed using Go language was used to package and deploy smart contracts. The supply-blockchain framework was used as the theoretical framework for prototype development, and agile project management was adopted to ensure timely completion. The results based on functional and performance testing demonstrate the prototype’s potential in alleviating port documentation bottlenecks and quickly delivering benefits to key stakeholders. Full article

The increasing reliance on computer networks and blockchain technology has led to a growing concern for cybersecurity and privacy. The emergence of zero-day vulnerabilities and unexpected exploits has highlighted the need for innovative solutions to combat these threats. Bug bounty programs have gained popularity as a cost-effective way to crowdsource the task of identifying vulnerabilities, providing a secure and efficient means of enhancing cybersecurity. This paper provides a comprehensive survey of various free and paid bug bounty programs in the computer networks and blockchain industry, evaluating their effectiveness, impact, and credibility. The study explores the structure, incentives, and nature of vulnerabilities uncovered by these programs, as well as their unique value proposition. A comparative analysis is conducted to identify advantages and disadvantages, highlighting the strengths and weaknesses of each program. The paper also examines the role of ethical hackers in bug bounty programs and their contributions to strengthening cybersecurity and privacy. Finally, the study concludes with recommendations for addressing the challenges faced by bug bounty programs and suggests potential future directions to enhance their impact on computer networks and blockchain security. Full article

The decentralized nature of blockchain enables data traceability, transparency, and immutability as complementary security features to the existing Internet of Things (IoT) systems. These Blockchain-based IoT (BIoT) systems aim to mitigate security risks such as malicious control, data leakage, and dishonesty often found in traditional cloud-based, vendor-specific IoT networks. As we steadily advance into the era of situation-aware IoT, the use of machine learning (ML) techniques has become essential for synthesizing situations based on sensory contexts. However, the challenge to integrate learning-based situation awareness with BIoT systems restricts the full potential of such integration. This is primarily due to the conflicts between the deterministic nature of smart contracts and the non-deterministic nature of machine learning, as well as the high costs of conducting machine learning on blockchain. To address the challenge, we propose a framework named Situ-Oracle. With the framework, a computation oracle of the blockchain ecosystem is leveraged to provide situation analysis as a service, based on Recurrent Neural Network (RNN)-based learning models tailored for the Situ model, and specifically designed smart contracts are deployed as intermediary communication channels between the IoT devices and the computation oracle. We used smart homes as a case study to demonstrate the framework design. Subsequently, system-wide evaluations were conducted over a physically constructed BIoT system. The results indicate that the proposed framework achieves better situation analysis accuracy (above 95%) and improves gas consumption as well as network throughput and latency when compared to baseline systems (on-chain learning or off-chain model verification). Overall, the paper presents a promising approach for improving situation analysis for BIoT systems, with potential applications in various domains such as smart homes, healthcare, and industrial automation. Full article

As blockchain becomes more widely used, a growing number of application fields are becoming interested in blockchain to benefit from its decentralised nature, invariability, security, transparency, quick transaction capabilities, and cost-effectiveness. Blockchain has a wide range of applications and uses in healthcare. Distributed ledger technology facilitates the secure transfer of patient medical records, manages the medicine supply chain, and creates an efficient, transparent, safe, and effective way of communicating data across global healthcare. The organ transplantation process (OTP) is one of the healthcare areas that benefit from the use of such technology to make its process more secure and transparent. In this article, we put forward a systematic literature review analysis on the application of blockchain to the OTP. Additionally, we address and highlight the barriers and challenges that arise while using blockchain technology for the OTP. We also offer some suggestions for future developments that would enhance blockchain’s implementation in the OTP domain. Full article

Practical Byzantine Fault Tolerance (PBFT) is the protocol of choice for many applications that require distributed consensus between a number of participant nodes. While PBFT assumes a single voting committee, many applications recognize different groups of participants that need to reach a consensus separately before accepting a proposal. To this end, we propose to count the votes by separate groups or committees of participating nodes, instead of all together as in the original PBFT. We then investigate the performance impact of this approach on the mean time to accept a data block and the number of nodes involved in making the final decision. Our results indicate that the proposed solutions impose a slight performance penalty which may be countermanded by reducing the quorum numbers needed in different subsets of the original committee. Full article

Blockchain technology is increasingly being recognized for its pivotal role in enhancing security, immutability, and transparency across government sectors, notably in land registration (LR) processes. This research emphasizes the need for contextually adapted blockchain technology solutions, particularly in resource-constrained and culturally diverse settings. Utilizing the elaborated action design research method, this study presents a Hyperledger-based blockchain technology system tailored for Sudan’s LR, addressing technical challenges, evaluation frameworks, privacy measures, and deployment strategies. This system not only facilitates secure and transparent land transactions from planning to certificate issuance, but also integrates the management of land sales, significantly reducing the need for intermediaries. By providing a detailed exploration of the system’s goals, technical hurdles, and practical deployment insights, this research contributes valuable knowledge to the implementation of blockchain technology in LR, with findings that are applicable to similar contexts globally. This study underscores the importance of customizing blockchain solutions to meet the unique requirements of different environments, thereby advancing digital government in resource-constrained settings. Full article

Many Blockchain-based approaches have been published in the field of health data management applications (HDMAs). However, no comprehensive guideline exists to guide the multiple and interdependent design decisions to develop such systems. This paper aims to support the HDMA system design processes by introducing a novel decision model. The model considers all relevant requirements, from regulatory context to user needs and trust considerations. To generate the decision model, we define a taxonomy that organizes previously published approaches by their technical design features and combines it with the trust assumptions of the participating actors according to the STRIDE method. The model aims to support a cohesive overall system design by addressing Blockchain type, off-chain storage, identity and access management, security decisions, and the specific use case of data donation. A group of experts evaluated the decision tree and its utility is demonstrated in three representative use cases. Special attention is paid to the use case of data donation via a data trustee, which is examined in detail. Full article

The rapid expansion of transactive energy has transformed traditional electricity consumers into producers, engaging in local energy trading. In the context of distributed energy transactions, blockchain technology has been increasingly applied to facilitate transaction transparency and reliability. However, due to the challenges in collecting accurate energy transmission data from power lines, most existing studies on the blockchain-based transactive energy market are still vulnerable to security attacks, such as malicious users misreporting energy prices, refusing to pay or refusing to transmit energy. Therefore, based on the co-simulation platform PEMT-CoSim and a blockchain, we establish a blockchain-based, reputation-aware secure transactive energy market (STEM) by introducing a reputation scheme to evaluate the trustworthiness of all prosumers and designing reputation-aware, multi-round double auction and energy transmission algorithms to detect and penalize malicious attacks. Furthermore, we run comprehensive experiments for different use cases. The results show that even with malicious participants, the proposed system can guarantee the interests of the honest participants and improve the robustness and effectiveness of the energy market. Full article

Federated learning (FL) has garnered significant attention as a novel machine learning technique that enables collaborative training among multiple parties without exposing raw local data. In comparison to traditional neural networks or linear models, decision tree models offer higher simplicity and interpretability. The integration of FL technology with decision tree models holds immense potential for performance enhancement and privacy improvement. One current challenge is to identify methods for training and prediction of decision tree models in the FL environment. This survey addresses this issue and examines recent efforts to integrate federated learning and decision tree technologies. We review research outcomes achieved in federated decision trees and emphasize that data security and communication efficiency are crucial focal points for FL. The survey discusses key findings related to data privacy and security issues, as well as communication efficiency problems in federated decision tree models. The primary research outcomes of this paper aim to provide theoretical support for the engineering of federated learning with decision trees as the underlying training model. Full article

Payment channels serve as an effective solution to the scalability problem of cryptocurrencies, which significantly increase transaction rates by allowing users to conduct large-scale offline transactions off-chain without posting everything to the blockchain. However, the existing payment channels lack privacy protection for the transaction amount and the linking relationship between the two parties to the transaction. Therefore, in order to address the scalability and privacy issues of cryptocurrencies such as Bitcoin, this paper proposes a zk-SNARKs-based anonymous payment channel (zk-APC), which supports an unlimited number of off-chain payments between the payer and the payee and protects the privacy of the participants. Specifically, the proposed scheme achieves relational anonymity and amount privacy for both on-chain and off-chain transactions in the payment channel through utilizing zero-knowledge proof (zk-SNARKs) and commitment schemes. This paper proves that the proposed method is more effective than similar schemes through a performance evaluation. Full article

Proof-of-Stake (PoS) protocols are widely accepted as a viable substitute for the Proof-of-Work-based consensus, which is why recent blockchain-based cryptocurrencies and applications, most notably Ethereum 2.0, are using some variant of PoS as the basis for the consensus protocol. However, the implementation of PoS protocols in Ethereum 2.0 are not without its share of problems and vulnerabilities, especially with respect to the malicious behavior of validator nodes. In this paper, we first review the basic tenets of PoS protocols. We then discuss some of the recently described attacks on the Ethereum 2.0 consensus, and we also show that some of the design rationales adopted in PoS implementation—the decentralization of the voting process in particular—have, in actuality, enabled attacks that can be launched at a very low cost to the attacker. We also propose simple remedies that can reduce or eliminate the impact of those attacks and can evaluate the performance of the Ethereum 2.0 consensus when these remedies are applied. Full article