Naveen Arali, D. G. Narayan, Altaf Husain M., P. S. Hiremath
Blockchain technology is a decentralized ledger system that finds applications in various domains such as banking, e-governance, and supply chain management. The consensus algorithm plays a crucial role in any blockchain network as it directly impacts the network's performance and security. There have been several proposed consensus mechanisms in the literature, including Proof of Work (PoW), Proof of Stake (PoS), Robust Proof of Stake (RPoS), and Delegated Proof of Stake (DPoS). Both Ethereum and Bitcoin utilize the PoW consensus mechanism, where nodes compete to solve puzzles in order to generate blocks, consuming significant processing power. On the other hand, the PoS consensus mechanism selects miners based on the stakes they hold, making it more energy efficient. However, PoS has drawbacks such as vulnerability to coin age accumulation attacks and the potential for partial centralization. In this work, we present a consensus mechanism known as Delegated Proof of Stake with Downgrading Mechanism using Game Theory (DDPoS (GT)). This mechanism employs a two-step game strategy to divide nodes into strong and weak nodes, as well as attack and non-attack nodes. Later, the results of the two games are combined to enhance protocol efficiency and security. Experimental results using a private Ethereum-based network demonstrate that DDPoS (GT) performs better than PoS and DPoS in terms of transaction latency, average block waiting time, and fairness.
Cryptocurrency, despite the upsurge as a speculative investment, is still a long way from being people’s money. The extreme technicality poses a significant barrier for the general public to adopt it as a medium of exchange. Therefore, simplifying the payment process is a predominant necessity; for example, facilitation in adopting conventional payment instruments can bring convenience to both merchants and consumers. This article proposes a novel cryptocurrency card payment protocol leveraging the Payment Channel Network (PCN) concept, facilitating high throughput and affordable transactions. Our design is based on the Bitcoin-backed Lightning Network (LN) with adjustments to make it executable by a smart card. It also preserves the decentralized nature of cryptocurrencies, reduces operational costs in several ways, and allows instant settlement for the recipients as compared to both conventional and cryptocurrency card payment systems. Our game theoretical analysis, where we model the engagement between the cardholder and the card agent as a long-run extensive form game, attests that they accord with the protocol without experiencing any honest loss under pragmatic conditions. We also discuss the privacy features compared to conventional card payments and LN. The protocol can function independently, without the need for trust, and can also be regulated for those seeking government mediation. This approach can potentially revolutionize the payment landscape by allowing the public to use cryptocurrency for everyday transactions conveniently and allowing existing cryptocurrency holders to conduct affordable micropayments.
This chapter involves numerous examples, using management cases and technology use cases, to understand the practical uses of Web 3 technologies. A discussion is had on Web 3 foundational concepts such as smart contracts, decentralized applications, decentralized identity and authentication, data privacy and control, and supply chain traceability. Then, cases related to DeFi, content monetization, decentralized exchanges, P2P lending, anonymized payments, lending platforms, stablecoins, financial inclusion and democratization, and autonomous funding are discussed. Tokenization led to the evolution of a new digital economy, and along with NFTs, the way digital art, real estate, and memorabilia are managed has changed. DAO is changing the way organizations work and are governed. Web 3 has several social applications and privacy-preserving technologies. Finally, interoperability options of Web 3 are discussed.
The rise of Bitcoin, a decentralized digital currency built on blockchain technology, marks the onset of a novel era in financial transactions and has generated substantial interest among academics and industry professionals. The fundamental notion of trust lies at the core of Bitcoin's success and broad acceptance. It is imperative to understand better the factors influencing trust in Bitcoin for the progression of scholarly advancement and practical implementations. Against this background, this paper explored the fundamental research question of what factors influence trust in Bitcoin. Firstly, we conducted a literature review and examined 22 empirical articles investigating determinants of trust in Bitcoin. Secondly, we conducted a quantitative survey with 372 participants to investigate the top 20 determinants of trust in Bitcoin. We leveraged our literature review results, considering that most examined articles used qualitative methods and often had a broader focus on blockchain technology rather than Bitcoin itself. Our survey results uncovered the perceived nature and strength of the relationship between the 20 determinants of trust in Bitcoin, particularly emphasizing how Bitcoin ownership status influenced these findings. In summary, our results contribute to an enhanced understanding of the elements shaping trust in Bitcoin, which is vital both from an academic standpoint and for its practical significance, considering the widespread public interest in Bitcoin.
Khushi Garg, Mahee Jattu, S. Hariharasitaraman, R. Raja Subramanian
The emergence of Web 3.0 has paved the way for a new generation of the internet that enables users to view, publish, and own content independently. This innovation is being driven by a combination of blockchain, semantic communication, edge computing, and artificial intelligence, which together create value networks that facilitate participatory decision-making. Blockchain, in particular, offers security services by recording content in a decentralized and transparent manner. Additionally, it is compatible with decentralized wireless edge computing designs that can accurately express the intended meanings of contents without requiring a lot of resources. Building on this foundation, this research proposes a paradigm for unified blockchain-semantic ecosystems for Web 3.0 with wireless edge intelligence. Specifically, we present a semantic proof technique built on Oracle that enables Web 3.0's off-chain and on-chain interactions. To improve interaction efficiency and support Web 3.0, Oracle has developed an adaptable Deep Reinforcement Learning-based sharding technique. Our work also introduces a blockchain-based semantic exchange architecture that tokenizes semantic data into non-fungible tokens (NFT) for semantic exchange in this system. We employ Zero-Knowledge Proof to trade real semantic information without publicly posting it before accepting payment, in contrast to traditional NFT marketplaces. This makes it possible to trade fairly and privately. Overall, our proposed framework can precisely perform decentralized semantic sharing and information transfer, further achieving the advantages of semantic extraction and communication in Web 3.0.
C. K. Shinzeer, Ajay Shriram Kushwaha, Avinash Bhagat
Blockchain technology is a distributed, accessible, open, and decentralized digital ledger used in healthcare to record transactions between devices. It addresses issues like data integrity, privacy, and confidentiality. The COVID-19 pandemic has accelerated the deployment of digital technologies, such as Distributed Ledger Technology, which enables a decentralized consensus between operational data states. This technology can enhance data access, integrity, and patients’ control over their credentials. A survey was conducted with the help of the World Health Organization, Kaggle, and the Ministry of Health Government of India and Kerala with the aim to identify potential uses for blockchain technology in immunization and the collection of patient data.
With the development of agricultural information technology, the Internet of Things and blockchain have become important in the traceability of agricultural products. Sensors collect real-time data in agricultural production and a blockchain provides a secure and transparent storage medium for these data, which improves the transparency and credibility of agricultural product traceability. However, existing agricultural product traceability solutions are limited by the immutability of the blockchain, making it difficult to delete erroneous data and modify the scope of data sharing. This damages the credibility of traceability data and is not conducive to the exchange and sharing of information among enterprises. In this article, we propose an agricultural product traceability data management scheme based on a redactable blockchain. This scheme allows agricultural enterprises to encrypt data to protect privacy. In order to facilitate the maintenance and sharing of data, we introduce a chameleon hash function to provide data modification capabilities. Enterprises can fix erroneous data and update the access permissions of the data. To improve the efficiency of block editing, our scheme adopts a distributed block editing method. This method supports threshold editing operations, avoiding single-point-of-failure issues. We save records of data modifications on the blockchain and establish accountability mechanisms to identify malicious entities. Finally, in this paper we provide a security analysis of our proposed solution and verify its effectiveness through experiments. Compared with the existing scheme, the block generating speed is improved by 42% and the block editing speed is improved by 29.3% at 125 nodes.
Tieliang Gao, Li Duan, Lufeng Feng, Wei Ni · 5 authors
Service composition platforms play a crucial role in creating personalized service processes. Challenges, including the risk of tampering with service data during service invocation and the potential single point of failure in centralized service registration centers, hinder the efficient and responsible creation of service processes. This paper presents a novel framework called Context-Aware Responsible Service Process Creation and Recommendation (SPCR-CA), which incorporates blockchain, Recurrent Neural Networks (RNNs), and a Skip-Gram model holistically to enhance the security, efficiency, and quality of service process creation and recommendation. Specifically, the blockchain establishes a trusted service provision environment, ensuring transparent and secure transactions between services and mitigating the risk of tampering. The RNN trains responsible service processes, contextualizing service components and producing coherent recommendations of linkage components. The Skip-Gram model trains responsible user-service process records, generating semantic vectors that facilitate the recommendation of similar service processes to users. Experiments using the Programmable-Web dataset demonstrate the superiority of the SPCR-CA framework to existing benchmarks in precision and recall. The proposed framework enhances the reliability, efficiency, and quality of service process creation and recommendation, enabling users to create responsible and tailored service processes. The SPCR-CA framework offers promising potential to provide users with secure and user-centric service creation and recommendation capabilities.
Oleksandr Kuznetsov, Dzianis Kanonik, Alex Rusnak, Anton Yezhov · 6 authors
The scalability of blockchain technology remains a pivotal challenge, impeding its widespread adoption across various sectors. This study introduces an innovative approach to address this challenge by proposing the adaptive restructuring of Merkle and Verkle trees, fundamental components of blockchain architecture responsible for ensuring data integrity and facilitating efficient verification processes. Unlike traditional static tree structures, our adaptive model dynamically adjusts the configuration of these trees based on usage patterns, significantly reducing the average path length required for verification and, consequently, the computational overhead associated with these processes. Through a comprehensive conceptual framework, we delineate the methodology for adaptive restructuring, encompassing both binary and non-binary tree configurations. This framework is validated through a series of detailed examples, demonstrating the practical feasibility and the efficiency gains achievable with our approach. Moreover, we present a comparative analysis with existing scalability solutions, highlighting the unique advantages of adaptive restructuring in terms of simplicity, security, and efficiency enhancement without introducing additional complexities or dependencies. This study's implications extend beyond theoretical advancements, offering a scalable, secure, and efficient method for blockchain data verification that could facilitate broader adoption of blockchain technology in finance, supply chain management, and beyond. As the blockchain ecosystem continues to evolve, the principles and methodologies outlined herein are poised to contribute significantly to its growth and maturity.
Sharding technologies allow the Internet of Things (IoT) to deploy blockchains in large-scale applications with good scalability. However, conventional sharding strategies in IoT blockchain are highly restricted because most IoT devices are dynamic and heterogeneous. They fail to partition and reconfigure shards with a fine-balanced tradeoff between throughput and security. Therefore, we propose SmartChain, which is a dynamic and self-adaptive sharding framework devised for making sharding decisions on the IoT blockchain featured with dynamics and heterogeneity. Specifically, we elaborate on how SmartChain performs reconfiguration and provide a quantitative analysis of shard performance. We then formulate the long-term tradeoff of throughput and security as a Markov decision process. Considering the nature of time-varying devices (e.g., amount of computing power, location), we develop a Transferable Proximal Policy Optimization (PPO) with Demonstrations algorithm, namely TPPOD, to help quickly reconfigure shards when the environment changes. Thus, based on current state, SmartChain can adaptively and dynamically select shard number, partition structure, and primary selection mode. Evaluations show that SmartChain enables high throughput and low risk of security, and reduces 70% of the training time averaged over baselines. Our implementation of TPPOD is 8.3 times of average system reward compared with the PPO-based sharding strategy with uniform sampling.
Hugo Schnoering, Pierre Porthaux, Michalis Vazirgiannis
Exploring transactions within the Bitcoin blockchain entails examining the transfer of bitcoins among several hundred million entities. However, it is often impractical and resource-consuming to study such a vast number of entities. Consequently, entity clustering serves as an initial step in most analytical studies. This process often employs heuristics grounded in the practices and behaviors of these entities. In this research, we delve into the examination of two widely used heuristics, alongside the introduction of four novel ones. Our contribution includes the introduction of the \textit{clustering ratio}, a metric designed to quantify the reduction in the number of entities achieved by a given heuristic. The assessment of this reduction ratio plays an important role in justifying the selection of a specific heuristic for analytical purposes. Given the dynamic nature of the Bitcoin system, characterized by a continuous increase in the number of entities on the blockchain, and the evolving behaviors of these entities, we extend our study to explore the temporal evolution of the clustering ratio for each heuristic. This temporal analysis enhances our understanding of the effectiveness of these heuristics over time.
Bitcoin’s success as a global cryptocurrency has paved the way for the emergence of blockchain, a revolutionary category of distributed systems. However, the growing popularity of blockchain has led to a significant divergence from its core principles in many systems labeled as “blockchain.” This divergence has introduced complexity into the blockchain ecosystem, exacerbated by a lack of comprehensive reviews on blockchain and its variants. Consequently, gaining a clear and updated understanding of the diverse spectrum of current blockchain and blockchain-like systems has become challenging. This situation underscores the necessity for an extensive literature review and the development of thematic taxonomies. This survey seeks to offer a comprehensive and current assessment of existing blockchains and their variations while delineating the boundaries between blockchain and blockchain-like systems. To achieve this objective, we propose a holistic reference model for conceptualizing and analyzing these systems. Our layer-wise framework envisions all distributed ledger technologies (DLTs) as composed of four principal layers: data, consensus, execution, and application (DCEA). In addition, we introduce a new taxonomy that enhances the classification of blockchain and blockchain-like systems, offering a more useful perspective than existing works. Furthermore, we conduct a state-of-the-art review from a layered perspective, employing 23 evaluative criteria predefined by our framework. We perform a qualitative and quantitative comparative analysis of 44 DLT solutions and 26 consensus mechanisms while discussing differences and boundaries between blockchain and blockchain-like systems. We emphasize the significant challenges and tradeoffs encountered by distributed ledger designers, decision-makers, and project managers during the design or adoption of a DLT solution. Finally, we outline crucial research challenges and directions in the field of DLTs.
블록체인에 대한 관심이 많아지고, 이더리움의 사용량이 증가함에 따라 블록체인 상태 데이터는 폭발적으로 증가하였는데, 이는 사용자의 네트워크 참여를 어렵게 만들었다. 본 논문에서는 상태 데이터의 상당수를 차지하는 스토리지 트라이를 과거 트랜잭션 데이터를 기반으로 최적화하는 방법을 제안하고자 한다. 본 연구에서는 1,400만 블록의 거대한 스토리지 트라이 중에서 100만 블록동안 한 번도 등장하지 않은 스토리지 트라이를 삭제하여 19.6%인 10.8GB의 저장공간을 줄였다. 본 논문의 연구 결과인 데이터 기반 스토리지 트라이 최적화를 기반으로 더욱 효과적인 스토리지 트라이 최적화를 제안할 수 있을 것으로 기대한다.
Ahsan Waseem, Mohd Bilal, Abhishek Bhardwaj, M. Saad Bin Arif · 5 authors
This article explores energy trading in grid-connected microgrids powered by renewable sources, utilizing cryptocurrency and blockchain technology. Through net metering, it emphasizes the proactive roles of prosumers and consumers in managing excess energy. The study investigates peer-to-peer energy transfers with blockchain-based cryptocurrencies, high-lighting their advantages in affordability, trade efficiency, and openness. Real-world case like LO3 Energy and Power Ledger are examined to address regulation, scalability, and cybersecurity concerns. The paper explores blockchain-enabled energy trade revolutionizing the industry, enhancing community resilience, accelerating renewable energy adoption, and reducing reliance on outdated technologies.
S Sarumathi, Apoorv Raj Saxena, Yash Raj Saxena, Mehreen S Md Sana · 6 authors
Decentralized Finance (DeFi) represents an alternative paradigm in financial infrastructure, operating a top the Ethereum Blockchain. DeFi leverages Automated Market Makers (AMMs) to facilitate the exchange of coins/tokens within Liquidity Pools (LPs). However, the current framework limits transactions to a single chain, resulting in prolonged processing times for cross-chain transactions. The principal drawbacks of existing AMMs include protracted transaction confirmation periods and constraints in single-chain functionality. This paper introduces Mixta, a web-based multi-chain interoperable AMM, aiming to address these limitations. Mixta empowers users to seamlessly exchange assets across different chains, ultimately reducing transaction confirmation times.
Wireless community networks (WCNs) represent bottom-up network infrastructures facing the following challenges: (1) Managing diverse devices, (2) Establishing effective real-time incentives, (3) Addressing anomalies, attacks, and faults, and (4) Ensuring data integrity verification. Inspired by [2], we introduce the decentralized wireless community network (DeWCN) concept, enabling community members to contribute resources to a common resource pool in a verifiable and incentivized manner. Consensus participants, selected from conflict-free network areas, maintain a distributed ledger with partial Byzantine fault tolerance for transparency and protocol automation. By leasing out storage, computing, and bandwidth resources with globally agreed-upon contributions, individuals can receive real-time cost compensation.
Cryptocurrency is rapidly emerging as a prominent player in the global financial system, characterized by its decentralized nature and the absence of centralized government oversight. However, this autonomy raises significant environmental concerns primarily stemming from the energy-intensive mining process. Crypto mining, central to the creation of new coins and transaction validation, results in substantial carbon emissions and energy consumption. This study employs bibliometric analysis using RStudio to scrutinize the data sourced from the Scopus database. Data selection adhered to specific inclusion criteria, focusing on research articles and documents in the English language. Exclusion criteria targeted the elimination of review papers, conference reviews, short surveys, notes, and articles in languages other than English. China emerges as the foremost contributor with a frequency of 348 and a total citation count of 1259, followed by the USA with 594 citations. Notably, the keywords "blockchain" and "bitcoin" surface most frequently, occurring 293 and 148 times, respectively. The study posits that China's decision to ban cryptocurrency due to economic concerns has likely contributed to heightened global awareness of cryptocurrencies. In contrast, the USA has actively embraced cryptocurrencies, fostering their widespread circulation. Consequently, these two countries have emerged as leading contributors to energy consumption in the cryptocurrency sector. Blockchain, originally a broad concept, has found applications in diverse domains such as marketing, finance, healthcare, supply chain, and the Internet of Things (IoT). This widespread adoption has expanded the scope of energy consumption considerations from cryptocurrencies to encompass blockchain technology as a whole. Future research should focus on mining regulation, alternative mechanisms, renewable energy sources, technological advancements, and carbon offsetting solutions. The article also addresses its limitations and the future scope of the study in detail.
In recent years, advancements in rooftop solar panel technology have sparked a revolution in the electricity markets. This has given rise to a new concept of energy exchange—the ability for consumers and producers to trade localized energy. This concept has been made possible by the emergence of blockchain technology, which has gained significant traction in the energy markets. Its unique ability to facilitate peer-to-peer (P2P) energy transactions has made it a promising solution for the trilemma of scalability, security, and decentralization. However, while blockchain technology has shown great potential, it is still in its early stages of development and has yet to reach its full potential. To fully understand the potential of blockchain technology in P2P energy trading, it is important to explore the trilemma in depth. This study proposes a blockchain-based scalability solution with a focus on P2P energy trading. This strategy is supported by empirical modeling, utilizing data gathered from a trial case study. The results of this study demonstrate that the suggested technique outperforms base-layer models in terms of scalability while still maintaining the essential elements of security and decentralization. This proposed solution not only has the potential to revolutionize the energy markets but also has broader implications. By providing a more secure and decentralized platform for P2P energy trading, it has the potential to address issues of energy distribution inequality and promote the adoption of renewable energy. With blockchain technology, individuals and communities have the opportunity to take control of their energy usage and production, reducing their reliance on traditional centralized energy systems. This not only has the potential to lower energy costs for consumers but also contributes to the overall goal of reducing carbon emissions and mitigating the effects of climate change. The combination of rooftop solar panel technology and blockchain applications has the potential to create a significant shift toward decentralized and sustainable energy systems. This will not only benefit individuals and communities but also have a positive impact on the environment and the global energy market. However, for this transition to occur, it is crucial that governments and energy companies continue to support and invest in these advancements.
Mikel Cortes-Goicoechea, Csaba Király, Dmitriy Ryajov, José L. Muñoz · 5 authors
Scalability in blockchain remains a significant challenge, especially when prioritizing decentralization and security. The Ethereum community has proposed comprehensive data-sharding techniques to overcome storage, computational, and network processing limitations. In this context, the propagation and availability of large blocks become the subject of research to achieve scalable data-sharding. This paper provides insights after exploring the usage of a Kademlia-based Distributed Hash Table (DHT) to enable Data Availability Sampling (DAS) in Ethereum. It presents a DAS-DHT simulator to study this problem and validates the results of the simulator with experiments in a real DHT network, InterPlanetary File System (IPFS). Our results help us understand what parts of DAS can be achieved based on existing Kademlia DHT solutions and which ones cannot. We discuss the limitations of DHT solutions and discuss other alternatives.
Sharding is a promising solution to enhance the scalability of blockchain. However, previous sharding systems adopt the lock-based cross-shard protocol to exclusively handle one-shot cross-shard transactions, leading to low-efficiency executions and unavailable calls when handling complex cross-shard contracts that introduce multi-shot cross-shard transactions to invoke multiple contracts managed by different shards.In this paper, we aim to enable efficient execution of arbitrarily complex cross-shard contracts in blockchain sharding systems. First, we perform a calling-flow analysis on Ethereum contracts with more than 180 million real-world transactions and find that about 30% transactions invoke complex contracts. Then, motivated by the properties of these complex contracts, we propose an off-chain execution model, called ShardCon, to achieve efficient executions for complex cross-shard contracts by decoupling the contract execution from the cross-shard consensus. Next, we introduce a cross-shard contract execution engine and a contract-driven deployment rule to the overheads introduced by off-chain executions. Moreover, to adapt to the multi-chain property of a sharding system, we introduce an off-chain state atomic commit protocol. Finally, we implement a prototype and evaluate it with concrete cross-shard contracts, showing that ShardCon can achieve more than 10x increase in throughput and 2x decrease in confirmation latency than the state-of-the-art sharding systems.
Xiaokang Wang, Laurence T. Yang, Dongdong Huo, Lei Ren · 5 authors
Internet-of-Things (IoT), is the comprehensive interconnection systems of computational, networking and physical devices with the important goal of providing proactive and personalized services efficiently. The foundation of such services is big data integration and processing among various devices, which brings important challenges including data fusion, transferring and sharing of computational results. On the other hand, decentralized blockchain platforms provide novel technologies for reliable IoT data integration and processing. In addition, to facilitate decentralization and distribution of IoT big data, tensor-train (TT), as a tensor decomposition method, can play a vital role. Therefore, in this paper, a tensor-train-based permissioned-private (P2) blockchain is proposed to realize the organization, integration, sharing and applications of IoT data for intelligent IoT services. To demonstrate the performance of the proposed method, case studies with IoT data are carried out on permissioned-private chain platform to measure its performance.
Pengfei Huang, Xiaojun Ren, Teng Huang, Arthur Sandor Voundi Koe · 6 authors
Node synchronization is essential for the stability of the Bitcoin network. Critics have raised doubts about the ability of a new node to quickly and efficiently synchronize with the Bitcoin network and alleviate the storage pressure from existing full nodes to stockpile new data. Basic pruning and other techniques have been explored to address these concerns but have been insufficient to reduce node synchronization delay and effectively suppress the growth of synchronized data. In this study, we propose SnapshotPrune, a novel pruning and synchronization protocol that achieves fast node bootstrapping in the Bitcoin blockchain. Real Bitcoin historical data are leveraged to measure the synchronization time and monitor the network traffic during node bootstrapping. The protocol requires data downloads that are 99.70% less than Bitcoin Core, 81% less than CoinPrune, and 60% less than SnapshotSave, thereby saving 97.23% of download time. Findings show that the proposed design enhances the storage efficiency and reduces the node synchronization delay compared with existing techniques. We hypothesize that the efficiency of this protocol increases with the block height.