Blockchain-based Smart Contracts Research Articles

Blockchain based secure energy marketplace scheme to motivate P2P microgrids

<span lang="EN-GB">In the past years trend of microgrids is increasing very fast to reduce peak-hour costs. However, in these systems, third parties are still involved in selling surplus energy. This results in increased cost of energy and there are many operational and security barriers in such systems. These issues can be solved by the decentralized distributed system of microgrids where a consumer can locally sell their surplus energy to another consumer. To deploy such a system, one must consider security barriers for the transaction of energy. This paper proposes a solution to these problems by devising a scheme as a marketplace where users interact with each other to buy and sell energy at better rates and get energy-generating resources on lease so that users do not have to worry about capital investment. Agreement between owner of resources and consumer is recorded on blockchain based smart contracts. In this paper, a survey is performed for existing well known, decentralized energy solutions. This paper also proposes an extra layer of security to leverage a shielded execution environment so that information of energy generated, utilized, and shared cannot be changed by consumers and third parties even if the system is compromised.</span>

DIM-DS: Dynamic Incentive Model for Data Sharing in Federated Learning Based on Smart Contracts and Evolutionary Game Theory

With the development of big data, data sharing has become a hot topic. According to the previous research on data sharing, there is a problem with regard to how to design an effective incentive mechanism to make users willing to share data. First, we integrate the incentives based on reputation and payment and introduce “credibility coins” as a cryptocurrency for data-sharing transactions, to encourage users to participate honestly in the data-sharing process based on federated learning. Second, we propose a dynamic incentive model based on the evolutionary game theory to model the game process of users in data sharing and analyze the stability of their strategies. Finally, based on the results of this analysis, we use the blockchain-based smart contract technology to dynamically adjust the participation benefits of users under different conditions in order to promote users to join consortium blockchains more often and steadily to participate in model training for federated learning and obtain better model accuracy. Our work is the first to apply the evolutionary game theory to the study of incentives in federated learning, and plays a leading role in the study of incentives in federated learning. Experimental simulation validation shows that our DIM-DS model can adequately motivate users to participate in the collaborative task of data sharing and maintain stability. The model can maximize the effectiveness of the federated learning model.

A Mixed Review of Cash Flow Modeling: Potential of Blockchain for Modular Construction

Cash is considered the most critical resource in construction projects. However, many contractors fail to obtain adequate liquidity due to a lack of proper cash flow management. Therefore, numerous research studies have been conducted to address cash flow-related issues in the construction industry. However, the literature still lacks a comprehensive review of cash flow management, methods and topics, in the construction industry. This study contributes by providing a holistic, up-to-date, and thorough review of 172 journal articles on construction cash flow. To achieve this primary objective, the study applies a mixed review methodology using scientometric and systematic reviews. The scientometric analysis provides the most contributing scholars, the timeline of cash flow research attention, and keywords clustering. On the other hand, the systematic analysis categorizes the cash flow themes, identifies current literature gaps, and highlights future research areas in the cash flow domain. The results show that cash flow analysis gained more research attention in the last two decades, cash flow-based schedule is the most frequent topic in the literature, and optimization techniques are predominant in the literature. Consequently, the study highlights five potential research frontiers. Further, an automated payment framework for modular construction projects using Blockchain-based smart contracts is developed to address some of the literature limitations. This study provides a guideline for future research efforts and raises researchers’ awareness of the latest trends and methods of construction cash flow analysis.

Toward Vulnerability Detection for Ethereum Smart Contracts Using Graph-Matching Network

With the blooming of blockchain-based smart contracts in decentralized applications, the security problem of smart contracts has become a critical issue, as vulnerable contracts have resulted in severe financial losses. Existing research works have explored vulnerability detection methods based on fuzzing, symbolic execution, formal verification, and static analysis. In this paper, we propose two static analysis approaches called ASGVulDetector and BASGVulDetector for detecting vulnerabilities in Ethereum smart contacts from source-code and bytecode perspectives, respectively. First, we design a novel intermediate representation called abstract semantic graph (ASG) to capture both syntactic and semantic features from the program. ASG is based on syntax information but enriched by code structures, such as control flow and data flow. Then, we apply two different training models, i.e., graph neural network (GNN) and graph matching network (GMN), to learn the embedding of ASG and measure the similarity of the contract pairs. In this way, vulnerable smart contracts can be identified by calculating the similarity to labeled ones. We conduct extensive experiments to evaluate the superiority of our approaches to state-of-the-art competitors. Specifically, ASGVulDetector improves the best of three source-code-only static analysis tools (i.e., SmartCheck, Slither, and DR-GCN) regarding the F1 score by 12.6% on average, while BASGVulDetector improves that of the three detection tools supporting bytecode (i.e., ContractFuzzer, Oyente, and Securify) regarding the F1 score by 25.6% on average. We also investigate the effectiveness and advantages of the GMN model for detecting vulnerabilities in smart contracts.

Privacy and Trust in pHealth - Past, Present and Future.

From beginning to today, pHealth has been a data driven service that collects and uses personal health information (PHI) for personal health services and personalized healthcare. As a result, pHealth services use intensively ICT technology, sensors, computers and mathematical algorithms. In past, pHealth applications were focused to certain health or sickness related problem, but in today they use mobile devices, wireless networks, Web-technology and Cloud platforms. In future, pHealth uses information systems that are highly distributed, dynamic, increasingly autonomous, multi-stakeholder data driven eco-system having ability to monitor anywhere person's regular life, movements and health related behaviours. Because privacy and trust are pre-requirements for successful pHealth, this development raises huge privacy and trust challenges to be solved. Researchers have shown that current privacy approaches and solutions used in pHealth do not offer acceptable level of privacy, and trust is only an illusion. This indicates, that today's privacy models and technology shall not be moved to the future pHealth. The authors have analysed interesting new privacy and trust ideas published in journals, and found that they seem to be effective but offer only a partial solution. To solve this weakness, the authors used a holistic system view to aspects impacting privacy and trust in pHealth, and created a template that can be used in planning and development future pHealth services. The authors also propose a tentative solution for future trustworthy pHealth. It combines privacy as personal property and trust as legal binding fiducial duty approaches, and uses a Blockchain-based smart contract solution to store person's privacy and trust requirements and service providers' promises.

Visualization of blockchain-based smart contracts for delivery, acceptance, and payment process using BIM

Building Information Modeling (BIM) provides an excellent opportunity to digitally document and visually display construction projects’ information throughout their whole lifecycle. Another recent technology that fosters the digital transformation of the construction sector is blockchain-based smart contract. In combination with BIM models, such smart contract can be used for delivery, acceptance, and payment (DAP) process automation in the construction industry. The DAP process can be modelled by using smart contracts and securely stored via a blockchain. Since smart contracts are programming codes, for stakeholders it is difficult to understand what is exactly written in them. Therefore, it is necessary to visualize the state and executed transactions of the deployed smart contracts. In this paper, a framework is highlighted to record and visualize the status of the DAP processes by combining BIM with smart contracts using the Business Process Model and Notation (BPMN) to develop a smart contract system. With the help of suitable visualization concepts, the individual transactions of the blockchain can be displayed in a comprehensible way. The feasibility of the framework is presented through an illustrative implementation of the smart contract system. The proposed framework can help project participants better understand the current state of a smart contract.

A Privacy-Preserving Authentic Healthcare Monitoring System Using Blockchain

Integrating the internet of things (IoT) and healthcare monitoring systems is one of the most dynamic innovations in the research area. Since the tremendous number of IoT devices in smart healthcare systems is increasing exponentially, privacy and security issues related to the patient's data are significant concerns. The authors propose an access control for a healthcare monitoring system using blockchain-based smart contracts. They created four smart contract forms for user registration, authentication, access control including misbehavior detection and access revocation. The sensor automatically measures the patient's health data and filters the data before determining whether to write the data into the blockchain or not. The sensor detects abnormal data and alerts doctors and hospitals for immediate treatment. The efficiency of the proposed framework is verified by performance evaluation based on the Ethereum test environment. The proposed system outperforms existing approaches by reducing deployment and execution latency and average response latency in the real-time smart healthcare system.

A Conceptual Model of Continuous Government Auditing Using Blockchain-Based Smart Contracts

This study examines how blockchain-based smart contracts for government financial and nonfinancial events can enable the real-time, continuous auditing of integrated data and provide government auditors with a higher level of transparency. The proposed model uses a combination of blockchain technology and a continuous auditing methodology that may improve the auditing effectiveness and efficiency of governmental agencies. This study’s approach comprises three steps. First, we describe the current governmental auditing practices and the core concepts and features of the blockchain. Second, we discuss the payment process used by government agencies. Third, we examine the implementation of a blockchain-based smart-contracts framework for government auditing using the government procurement process.

Challenges Smart Grid in Blockchain Applications

Globally, interest in renewable energy has grown recently. The microgrid integrates traditional dispersed energy resources utilizing technological tools and information technology, making it more effective and flexible to enhance the economic and environmental situations (IT). One of these technologies that has drawn interest in microgrid applications to create a sustainable society is blockchain. The blockchain idea can offer immutability for microgrid transactions such as recording power generation levels and confirming transactions between generators and end consumers. By eliminating the need to connect with third parties, blockchain-based smart contracts can be utilized for auditing or resolving a transaction dispute between the producers and the users. In this paper, we highlight many recent research projects on blockchain applications in microgrids and the use of smart contracts to enhance the transactive resilience in microgrids.

Application of blockchain and smart contracts in autonomous vehicle supply chains: An experimental design

With the rise of digital sustainable business models in the Autonomous Vehicles (AV) industry, the traditional automakers are undergoing a major restructuring in their key performance areas and associated supply chains processes. Focusing on an innovative AV design (AD) concept, this paper investigates how Artificial Intelligence (AI) and Blockchain-based Smart Contracts can enhance sustainable supply chain operations. A novel design element, Margin Indicator (MI), is developed to obtain reliable predictive analytics results from the mainstream machine learning algorithms. The proposed approach supports a robust control of costs and energy, while maintaining a high level of transparency in managing decentralized AV supply chain processes, monetary impacts, and environmental sustainability. Testing the developed concept through a preliminary case study, we observed a reduction in energy wastage and hidden financial transactions by 12.48% and 11.58%, respectively. Supported by the rapid advancement in the blockchain and AI technologies, the developed framework is expected to improve product traceability, transaction transparency, and sustainable economic growth for the AV supply chains.

Blockchain-based Smart Contract for Decentralized Marketplace

The advance of information technology has a growing influence on one of the most popular social trends: online shopping. The rising popularity of online shopping among the general public, as indicated by the growth in the number of online purchasers each year, has prompted business owners to pursue online ventures. The marketplace is intrinsically tied to online buying activity that connects merchants and customers, allowing customers to search for various goods and services from various providers. However, service failures are vulnerable to centralized market systems that emerge frequently. When the company's services to customers fail to satisfy consumer expectations. A breakdown in purchasing and selling essential services, including product delivery and customer support, is referred to as service failure. As a result, not only does this harm confidence, but it may also cause clients to migrate to an alternative marketplace. The marketplace's competitiveness is based on consumer confidence. The decentralized marketplace can address this security concern. A decentralized marketplace is meant to build a system that does not require the confidence of a third party using blockchain technology and smart contracts that can record all transactions clearly and consistently, allowing them to serve as a single point of truth between distrusting entities. The findings largely support the feasibility of Ethereum Smart Contracts to construct a decentralized marketplace. However, there are some places where further study and development are needed.

Blockchain-Based Smart Contract for P2P Energy Trading in a Microgrid Environment

The purpose of this study is to propose a method of peer-to-peer (P2P) energy trading that allow prosumers with energy deficiency to buy energy from prosumers with excess energy in a microgrid system. The proposed method solves the problems associated with lack of trust in P2P energy trading and utilized the blockchain technology that made it impossible to tamper with data. The data is referred as transaction generated by using blockchain. A blockchain based smart contract execute the trading and payment rules without the intermediaries. Thus, the security and fairness of energy trading are significantly enhanced compared to conventional database technology. Without the third-party intervention, a miner that is selected among the participants in the microgrid environment process all the transaction generated from buying and selling energy. The smart contract consists of two main components; bidding and settlement module, payment module. The smart contract deployed in blockchain test network to test the interaction of smart contract. From the simulation, the proposed method is validated using realistic data with the Ethereum Virtual Machine (EVM). The method will be expected to be useful to designers who need to integrate renewable energy in a microgrid system.

SoK: TEE-Assisted Confidential Smart Contract

The blockchain-based smart contract lacks privacy, since the contract state and instruction code are exposed to the public. Combining smart-contract execution with Trusted Execution Environments provides an efficient solution, called TEE-assisted smart contracts (TCSC), for protecting the confidentiality of contract states. However, the combination approaches are varied, and a systematic study is absent. Newly released systems may fail to draw upon the experience learned from existing protocols, such as repeating known design mistakes or applying TEE technology in insecure ways. In this paper, we first investigate and categorize existing systems into two types: the layer-one solution and the layer-two solution. Then, we establish an analysis framework to capture their common aspects, covering desired properties (for contract services), threat models, and security considerations (for underlying systems). Based on our taxonomy, we identify their ideal functionalities, and uncover fundamental flaws and challenges in each specification’s design. We believe that this work would provide a guide for the development of TEE-assisted smart contracts, as well as a framework to evaluate future TCSC systems.

Empirical Analysis of Vulnerabilities in Blockchain-based Smart Contracts

With the evolution of technology, blockchain a swiftly impending phenomenon i.e., "decentralized computing” is observed. The emergence of Smart Contracts (SC) has resulted in advancements in the application of blockchain technology. The Ethereum network’s computing capabilities and functionalities are founded on the basis of SC. A smart contract is a self-executing agreement between buyer and seller with the terms of the settlement between them, written directly as lines of code, existing across a distributed decentralized blockchain network. It is a decentralized software that runs on a blockchain autonomously, consistently, and publicly. Conversely, due to the complex semantics of fundamental domain-specific languages and their testability, constructing reliable and secure SC can be extremely difficult. SC might contain some vulnerabilities. Security vulnerabilities can originate from financial tribulations; there are a number of notorious events that specify blockchain SC could comprise numerous code-security vulnerabilities. Security and privacy of blockchain-based SC are very important, we must first identify their vulnerabilities before implementing them widely. Therefore, the purpose of this paper is to conduct a comprehensive experimental evaluation of two current security testing tools: Remix solidity static analysis plugin and Solium which are used for static analysis of SC. We have conducted an empirical analysis of SC for finding tangible and factual evidence, controlled by the scientific approach. The methodology’s first step is to gather all of the Ethereum SC and store them in a repository. The next step is to use the Remix solidity static analysis plugin and Solium to perform vulnerability assessments. The last step is to analyze the result of both tools and evaluate them on the basis of accuracy and effectiveness. The goal of this empirical analysis is to evaluate the two FOSS tools: Remix solidity static analysis plugin and Solium on the basis of accuracy and effectiveness. Some research questions were considered to reach the stated goal: What automated tools and frameworks are proposed in supporting the state-of-the-art empirical approach to SC vulnerability detection? How accurate are security analysis tools? And which tool has more accuracy rate? How effectively security analysis tools are detecting vulnerabilities in SC? And which is the most effective security analysis tool? We investigated the effectiveness and accuracy of security code analysis tools on Ethereum by testing them on a random sample of vulnerable contracts. The results indicate that the tools have significant discrepancies when it comes to certain security characteristics. In terms of effectiveness and accuracy, the Remix plugin outperformed and beat the other tool.

Towards Blockchain-Based Energy Trading: A Smart Contract Implementation of Energy Double Auction and Spinning Reserve Trading

The decentralization of power generation driven by the rise in the adoption of distributed energy resources paves the way for a new paradigm in grid operations. P2P energy trading is beneficial to the grid as well as the connected peers. A blockchain-based smart contract is well suited to transparently facilitate trades between energy consumers and producers without the services of intermediaries. In this paper, Ethereum-based smart contracts that facilitate double energy auction and spinning reserve trading are developed with Solidity, compiled, and deployed within the Remix IDE. Willing energy sellers/buyers submit offers/bids to a contract that implements the double auction procedure. In order to fulfil energy supply obligations, sellers are also able to purchase spinning reserves via another smart contract. The smart contracts’ effectiveness in performing the auction procedure and making payments is confirmed using an energy/reserve market scenario. The proposed scheme encourages further adoption of distributed energy resources and participation in local P2P energy trading.

Technology-driven solutions to banks’ de-risking practices in Hong Kong: FinTech and blockchain-based smart contracts for financial inclusion

This article examines banks’ de-risking practices inside Hong Kong's Anti-Money Laundering/Countering the Financing of Terrorism (AML/CFT) regime, a problem that has created considerable tension between the demands of AML/CFT prevention and those of financial inclusion. It unravels the public policy tensions stemming from a multitude of financial reform causes, namely the facilitation of AML/CFT regulatory compliance, the promotion of financial technology (FinTech) innovation and an ultimate expansion in financial inclusion. The article argues that tiered account services are an important first step towards financial inclusion, culminating in the introduction of simple bank accounts by some banks to mitigate the effect of de-risking. While proposed solutions such as the know-your-client utility system and central data repository may contribute to a digital financial inclusion framework, they are not tailored to solve a specific problem (de-risking). The article therefore proposes and evaluates whether FinTech and blockchain-based smart contracts qualify as alternative solutions to de-risking. The article aims to address those policy tensions and contribute to the regulatory policy formulation and the rule-making for financial law and regulation intended to facilitate financial inclusion.

Blockchain technology: a troubleshooter for blood cold chains

PurposeBlood cold chain (BCC) represents a system for preserving the blood during its journey from the donor to the ultimate transfusion site. Existing BCCs have many drawbacks related to information transparency and information security. Secured and real-time information sharing in BCC can bring several benefits. The purpose of this paper is to summarise the issues in typical BCCs and to explore the scope of blockchain in the management of BCCs.Design/methodology/approachIssues in the existing BCCs are identified through a narrative review. To explain the potential of blockchain in mitigating these issues, a blockchain-based traceability solution is demonstrated with respect to a particular BCC scenario. The BCC management system discussed in this study makes use of the Ethereum blockchain’s smart contract feature and internet of things (IoT) technology. The smart contract is written in the solidity programming language and tested and validated using the Remix integrated development environment.FindingsBCCs are concerned with several issues both from technical and non-technical perspectives. Blockchain technology is capable of troubleshooting the issues in the existing BCCs. Combining blockchain and IoT technology enables real-time information sharing among the entities. The demonstration presented in this work depicts how the blockchain-based smart contract can support operations in a typical BCC.Research limitations/implicationsThis paper explores the scope of blockchain in BCCs through a demonstration. To get insights into its technical and economical feasibilities, further investigations are needed.Originality/valueBlockchain-based traceability system presented in this work can be adopted in BCCs to ensure the quality of blood or blood products. Blockchain-based smart contracts can aid the BCCs to achieve a proper balance between blood shortage and outdating.

Blockchain Technology in the Chemical Industry.

This article presents a review of the application of blockchain and blockchain-based smart contracts in the chemical and related industries. We introduce the basic concepts of blockchain and smart contracts and explain how some of their features are enabled. We review several typical or novel applications of blockchain and smart contract technologies and their enabling concepts and underlying technologies. We classify the selected literature into five categories and discuss their motivations and technical designs. We recognize that the trend of decentralization creates a need to use blockchain and smart contracts to implement trust and distributed control mechanisms. We also speculate on future applications of blockchain and smart contracts. We believe that, in the future, blockchains with different consensus mechanisms will be studied and applied to achieve more efficient and practical decentralized systems. Also, blockchain-based smart contracts will be more widely applied to enhance autonomous distributed controls in decentralized systems.

Improving Diagnosis Through Digital Pathology: Proof-of-Concept Implementation Using Smart Contracts and Decentralized File Storage.

BackgroundRecent advancements in digital pathology resulting from advances in imaging and digitization have increased the convenience and usability of pathology for disease diagnosis, especially in oncology, urology, and gastroenteric diagnosis. However, despite the possibilities to include low-cost diagnosis and viable telemedicine, digital pathology is not yet accessible owing to expensive storage, data security requirements, and network bandwidth limitations to transfer high-resolution images and associated data. The increase in storage, transmission, and security complexity concerning data collection and diagnosis makes it even more challenging to use artificial intelligence algorithms for machine-assisted disease diagnosis. We designed and prototyped a digital pathology system that uses blockchain-based smart contracts using the nonfungible token (NFT) standard and the Interplanetary File System for data storage. Our design remediates shortcomings in the existing digital pathology systems infrastructure, which is centralized. The proposed design is extendable to other fields of medicine that require high-fidelity image and data storage. Our solution is implemented in data systems that can improve access quality of care and reduce the cost of access to specialized pathological diagnosis, reducing cycle times for diagnosis.ObjectiveThe main objectives of this study are to highlight the issues in digital pathology and suggest that a software architecture–based blockchain and the Interplanetary File System create a low-cost data storage and transmission technology.MethodsWe used the design science research method consisting of 6 stages to inform our design overall. We innovated over existing public-private designs for blockchains but using a 2-layered approach that separates actual file storage from metadata and data persistence.ResultsHere, we identified key challenges to adopting digital pathology, including challenges concerning long-term storage and the transmission of information. Next, using accepted frameworks in NFT-based intelligent contracts and recent innovations in distributed secure storage, we proposed a decentralized, secure, and privacy-preserving digital pathology system. Our design and prototype implementation using Solidity, web3.js, Ethereum, and node.js helped us address several challenges facing digital pathology. We demonstrated how our solution, which combines NFT smart contract standard with persistent decentralized file storage, solves most of the challenges of digital pathology and sets the stage for reducing costs and improving patient care and speed of diagnosis.ConclusionsWe identified technical limitations that increase costs and reduce the mass adoption of digital pathology. We presented several design innovations using NFT decentralized storage standards to prototype a system. We also presented the implementation details of a unique security architecture for a digital pathology system. We illustrated how this design can overcome privacy, security, network-based storage, and data transmission limitations. We illustrated how improving these factors sets the stage for improving data quality and standardized application of machine learning and artificial intelligence to such data.

Blockchain technologies for museum management. The case of the loan of cultural objects

ABSTRACT The paper investigates the application of blockchain technologies to cultural heritage organizations, with a focus on museums, and outlines the advantages and limits of such technologies applied to the loan of cultural objects. To this aim, the paper employs the qualitative methodology of case study and presents two cases concerning the development of blockchain-based tracking systems and blockchain-based smart contracts, and their application to museums for the management of the loan of cultural objects. The application of blockchain technologies facilitates the circulation of cultural items, with benefits for the overall cultural offer, the attractiveness of museums, and, possibly, the consequent tourist flows. Moreover, it is argued that the use of blockchain-based tracking systems and smart contracts for the management of loans of cultural objects between organizations allows to overcome some organizational issues and to reduce transaction costs. Limits of the blockchain technologies for museums and managerial implications are also discussed.