Hyeong Joon Kim, Hye Hyeon Kim, Hosuk Ku, Kyung Don Yoo · 11 authors
BACKGROUND The Health Avatar Platform provides a mobile health environment with interconnected patient Avatars, physician apps, and intelligent agents (termed IoA 3 ) for data privacy and participatory medicine; however, its fully decentralized architecture has come at the expense of decentralized data management and data provenance. OBJECTIVE The introduction of blockchain and smart contract technologies to the legacy Health Avatar Platform with a clinical metadata registry remarkably strengthens decentralized health data integrity and immutable transaction traceability at the corresponding data-element level in a privacy-preserving fashion. A crypto-economy ecosystem was built to facilitate secure and traceable exchanges of sensitive health data. METHODS The Health Avatar Platform decentralizes patient data in appropriate locations (ie, on patients’ smartphones and on physicians’ smart devices). We implemented an Ethereum-based hash chain for all transactions and smart contract–based processes to guarantee decentralized data integrity and to generate block data containing transaction metadata on-chain. Parameters of all types of data communications were enumerated and incorporated into 3 smart contracts, in this case, a health data transaction manager, a transaction status manager, and an application programming interface transaction manager. The actual decentralized health data are managed in an off-chain manner on appropriate smart devices and authenticated by hashed metadata on-chain. RESULTS Metadata of each data transaction are captured in a Health Avatar Platform blockchain node by the smart contracts. We provide workflow diagrams each of the 3 use cases of data push (from a physician app or an intelligent agents to a patient Avatar), data pull (request to a patient Avatar by other entities), and data backup transactions. Each transaction can be finely managed at the corresponding data-element level rather than at the resource or document levels. Hash-chained metadata support data element–level verification of data integrity in subsequent transactions. Smart contracts can incentivize transactions for data sharing and intelligent digital health care services. CONCLUSIONS Health Avatar Platform and interconnected patient Avatars, physician apps, and intelligent agents provide a decentralized blockchain ecosystem for health data that enables trusted and finely tuned data sharing and facilitates health value-creating transactions with smart contracts.
Existing studies on blockchain within land administration have focused mainly on replacing or complementing the technology for land registration and titling. This study explores the potential of using blockchain technology to enhance the transparency of all land administration processes using an integrative review methodology coupled with a framework analysis. This study draws on the Ghanaian land administration perspective to make this insightful. It appears possible to apply a permissionless public blockchain across all land administration processes. This integrates all departments, processes, and stakeholders of land administration to enhance openness, improve availability and accessibility to information, and foster participation for transparency simultaneously. This can change the transparency variation in land administration to be more equal and homogenous regardless of land type. This, however, depends on the standardization of processes across the divisions, as well as negotiation and consensus amongst all stakeholders, especially with chiefs. Limitations include: limited storage and scalability, as well as huge electricity consumption for operation. This study’s policy implications are a review of all paper-based land transactions, a comprehensive digitization of land administration processes, public–private partnership on blockchain-based land administration, and professionals and stakeholder education on the technology.
Ludwig Trotter, Mike Harding, Peter Shaw, Nigel Davies · 9 authors
Recent work has questioned the largely unconditional nature of charitable donations and explored the value of conditional giving with contemporary donors. In this paper, we extend this work by exploring how to operationalise features of conditionality in charitable giving, situated in the context of large international non-governmental organisations (NGOs). Building on prior engagements with international aid organisations, we present design considerations and a conceptual architecture supporting real-time, conditional giving for individual and institutional donations. Our architecture leverages properties of distributed-ledger technologies (DLT) to empower donors to (i) attach conditions to their donation, (ii) store funds in a secure, decentralised escrow and (iii) automatically release funds once conditions are met. Unlike prior work that envisions radical disintermediation and the removal of intermediate NGOs using DLT, our work recognises the expertise of NGOs in tackling complex global problems and instead investigates compelling new way for charities to increase transparency and accountability by introducing dynamic pledge controls.
As the most popular blockchain that supports smart contracts, there are already more than 296 thousand kinds of cryptocurrencies built on Ethereum. However, not all cryptocurrencies can be controlled by users. For example, some money is permanently locked in wallets' accounts due to attacks. In this paper, we conduct the first systematic investigation on locked cryptocurrencies in Ethereum. In particular, we define three categories of accounts with locked cryptocurrencies and develop a novel tool named CLUE to discover them. Results show that there are more than 216 million dollars value of cryptocurrencies locked in Ethereum. We also analyze the reasons (i.e., attacks/behaviors) why cryptocurrencies are locked. Because the locked cryptocurrencies can never be controlled by users, avoid interacting with the accounts discovered by CLUE and repeating the same mistakes again can help users to save money.
In this commentary, we argue that studies similar to Cennamo, Marchesi, and Meyer (2020) should distinguish four dimensions of control in blockchain governance, all of which could be more or less decentralized. For some of these dimensions, decentralization is likely beneficial, while for others centralization may be preferable. Cennamo et al. (2020) provide evidence that the initial design stages of blockchain systems benefit from centralization. Future research is needed to provide empirical insights for other dimensions of control in blockchain governance.
Zusammenfassung Blockchain verspricht, Intermediäre wie Banken überflüssig zu machen und durch dezentrale Peer-to-Peer-Netzwerke zu ersetzen. Dieser Beitrag stellt die Frage nach der Realisierbarkeit dieser Ankündigung sowie danach, welche gesellschaftlichen Implikationen damit verbunden sind. Eine historisch informierte theoretische Analyse zeigt, dass die Erzeugung von Kreditgeld durch Banken ein für kapitalistische Gesellschaften existenzieller Vorgang ist. Die Fiktion des Geldwerts bedarf ihrerseits glaubwürdiger Intermediäre, die dauerhaft in der Lage sind, die zeitliche und räumliche Stabilität des Geldes zu inszenieren. Explorative Interviews mit Akteuren im Finanzsektor in Kombination mit einer inhaltsanalytischen Auswertung von einschlägigen Blogs, White Papers und Artikeln der Wirtschaftspresse lassen vermuten, dass Blockchain Intermediäre keineswegs ausschaltet, sondern diejenigen mächtiger werden lässt, die in der Lage sind, die Technologie ihren Bedürfnissen entsprechend umzugestalten.
Healthcare data can be created, copied and modified faster than ever before. Data is the fuel behind more efficient care. Unfortunately, healthcare today suffers from compartmentalized and fragmented data, delayed communications, and disparate workflow tools caused by the lack of interoperability. Blockchain technology maybe the vehicle to solve these problems, as besides it possesses key properties, such as immutability, decentralization, and transparency, which potentially address pressing issues in healthcare, such as incomplete records at point of care and difficult access to patients' own health information. An efficient and effective healthcare system should be interoperable, allowing software apps and technology platforms to communicate securely and seamlessly, exchange data, and use the exchanged data across health organizations and app vendors. In this paper, we address the aspect of storage of Electronic Medical Records using smart contracts. The implementation is done using Ethereum's blockchain network to solve problems faced by centralized platforms. The results were encouraging, and the implementation was also successful in reducing storage costs by storing large files off-chain (IPFS).
Blockchain brings opportunities and challenges for financial data sharing services. The essential properties in a distributed multi-parties system are data access control and privacy control. This paper proposes a hierarchical data access model for financial services, which contains consent management and dynamic credits management. We implement fine-grained data access control through rating accredited data recipients (ADRs). By accessing corresponding blockchain service logs, ADRs' credits will dynamically be updated. The credits evaluation algorithm is responsible for calculating ADRs' credits based on their completion rate, business ethics rate, and feedback positive rate. Moreover, through applying smart contracts, the efficiency of consent management can be improved, and privacy policies can be managed elastically. Finally, we deploy smart contracts on the Ethereum Rinkeby testnet to evaluate the model feasibility. Furthermore, the theoretical analysis and experimental results indicate that the prototype is secure and efficient.
Xuan Son Ha, Hai Trieu Le, Nadia Metoui, Nghia Duong‐Trung
The cash on delivery (CoD) is currently one of the significant payment mechanism in many developing countries' E-commerce systems. A transaction between a seller and a purchaser is completed when the seller has agreed to exchange packaged goods for a payment from the purchaser. Building highly trustworthy, accountable, credible, and decentralized CoD systems to trace and track physical items is a very challenging task. Several technologies and models for deploying CoD-based applications have been proposed in the literature. In most scenarios, these models have been created with the aim of accommodating collaborative processes involving multiple participants, e.g. seller, purchasers, and shippers, that belong to independent organizations. However, these approaches face several limitations and require appropriate improvement to sustain CoD-based systems' adoption further. First of all, there are no incentives for participants to act honestly. Secondly, the shippers are often kept out of the delivery chain and are affected by or not involved in any incentives or logs. Last but not least, users' privacy can be easily compromised and sensitive data collected and generated during the transactions can be easily accessed and abused. Building upon these critical insights, we propose a novel decentralized marketplace mechanism using the smart contract via blockchain technology. Our approach operates by incentivizing all the participants to act honestly and fulfill their obligations without resorting to a trusted third party. It also integrates adapted access control protocols to protect user privacy. The model's architecture shows that our approach guarantees integrity and robustness. It contributes to effectively addressing the issues listed above. A complete code solution is publicized on the authors' GitHub repository to engage further reproducibility and improvement.
Jaydeep Deshpande, M.M. Shankare Gowda, Manish Dixit, M S Khubbar · 6 authors
Hundreds of public procurement projects are undertaken every day all over the country. The tenders for these projects are given to the winning contractor in an auction-like setting which have massive security issues. After a contractor wins a tender, the specifics of the progress of the work done are rarely properly monitored. The details of the finances spent on the project can be easily manipulated. To enable integrity, non-repudiation and immutability to the data requires the desirable technology to support the above requirements. Hence, the proposed system uses blockchain technology to provide transparency and trust to all parties involved in the network. The entire system consists of two modules such as the Tender Bidding system and Tender Monitoring system using a multi-organization blockchain network in the Hyperledger Fabric. The whole bidding process is improved by creating a decentralized descending auction system that will carry it out fairly and transparently. The Tender Monitoring system employs a custom endorsement policy to attain 100% consensus for attesting every transaction made regarding the progress of the project so that vital steps are ratified and recorded with evidence supporting their integrity. The main aspects of the system, its many components, deployment and drawbacks are viewed.
Sin Yee Teh, Angeline Kiew Heong Yap, Siew Chin Wong
Cryptocurrencies have become the buzzword among society, especially after some prominent companies such as Wikipedia, Microsoft and Amazon accept the use of cryptocurrencies. Nonetheless, accounting treatment of cryptocurrencies appears to be a challenging area for standard setters, financial statement preparers, and also users. This is mainly because elements of cryptocurrency do not explicitly fall under any existing accounting standards. The fact that cryptocurrencies are held for different business models and intentions may affect how it should be treated under accounting standards. Hence, this research aimed to examine factors that affect the accounting treatment of cryptocurrencies in Malaysia. Different factors were examined including the function of cryptocurrencies, conceptual framework of financial reporting and the legal status of cryptocurrencies. Targeted respondents involved in this research were accountants in Malaysia. Data collected were analysed using SPSS and SmartPLS 3. SPSS was mainly used to analyse the demographics of respondents whereas SmartPLS 3 was used to carry out reflective measurement model and structural model evaluation. The results concluded that all the independent variables which are the functions of cryptocurrencies, conceptual framework of financial reporting, and the legal status of cryptocurrencies have a significant relationship with the accounting treatment of cryptocurrencies. The results of this study provide an insight about factors that standards setters and financial standards should consider when accounting for cryptocurrencies’ transactions in order to provide faithful representation and relevant information. Some limitations and suggestions are included in this research to provide ideas for future researchers to carry out further research.
Cryptocurrencies and its underlying distributed ledger technology (DLT) introduces innovations to digital property and methods of information storage. Although capable of many uses, its most famous implementation is creating a new digital asset that underpins a system of direct 'peer-to-peer' online payments. This emerging technology disrupts the existing centralised digital payments system; itself underpinned by a model of 'trust' derived from state-franchised institutions. In this emerging world of cryptocurrencies, 'trust' does not derive from state-franchised institutions or intermediaries, but the technology and its network. Cryptocurrencies pose a range of conceptual and regulatory challenges. For instance, it challenges orthodox theoretical explanations of money. Furthermore, it re-enacts tensions between state control of monetary operations and private involvement in payments. Significantly, cryptocurrencies raise concerns regarding the adaptability of law in responding to emerging problems of financial crime, privacy protection and socio-economic participation. \n \n \nThis thesis assesses the extent to which existing legal frameworks for digital payments can respond to the cryptocurrency phenomenon. It focuses on the Electronic Money and Payment Service Regulations of 2011 and 2017, respectively. The thesis also analyses Common Law rules governing bank payments to ascertain the extent of applicability and suitability. The thesis argues that the underpinning private nature of cryptocurrencies make current legal frameworks incompatible. It also argues that, by mostly pursuing economic goals of efficiency, existing regulatory tools are inadequately prepared to respond to peculiar concerns thrown up by cryptocurrencies. As such, in its current framework, orthodox regulatory responses seem incapable of resolving the myriad of issues associated with the complex relationships between asset holders and crypto institutions. Ultimately, by prioritising efficiency over other values like privacy and inclusion, existing legal and regulatory rules implicitly protect the positional power of incumbents and preserve the hierarchical structure of the financial system. In this regard, the law has become an instrument deployed in curtailing cryptocurrencies from widespread adoption, for the benefit of the state and its franchise institutions. \n \n \nLegal reform is necessary. However, the thesis argues that such reform must not solely focus on economic goals which underpin market-focused legal interventions. Instead, an intervention must aim to promote innovation, protect consumers, widen participation and preserve personal liberties. The policymaker must first objectively assess the benefits that cryptocurrencies introduce into the payments system. By conducting such an objective assessment, this thesis ultimately concludes that, given the growing decline in cash use, cryptocurrencies are a viable alternative online payment instrument inbuilt with more robust protections and encouraging participation.
The large-scale integration of distributed energy resources has resulted in surgical changes in energy trading systems. Traditional centralized trading systems suffer from high management cost and low efficiency. The recent advance of blockchain technology has enabled the invention of distributed energy trading systems, which can overcome the limitations of centralized trading systems. However, the distributed energy trading systems also bring new security and privacy challenges. For instance, transactions on blockchain are publicly visible which can lead to privacy leakage of trading information. Moreover, user privacy can also be leaked during verification of the aggregated energy trading result. In this paper, we propose a privacy-preserving energy trading scheme based on blockchain to meet the security requirements for distributed energy trading. We adopt a stealth transmission approach based on blockchain to ensure data privacy and break the linkage between consumers and providers in the energy trading process. We also use the non-interactive zero-knowledge proof technology to achieve privacy-preserving and trustworthy trading result verification. Security analysis and evaluation results have demonstrated that the proposed scheme can effectively protect the data privacy for distributed energy trading systems.
Transactions (TX) sent and executed by a public Blockchain (BC) need to pay a TX fee. The fee is relative to the resources consumed when including the TX into a block. The sender of the TX pays for the fee in the native currency of the BC used. Such a fee protects the network from Denial-of-Service (DoS) attacks and provides incentives for TXs inclusion. BCs that support Smart Contracts (SC), thus, TXs can execute user-provided code, require a mechanism for fee calculation depending on the resources consumed by the code executed. Ethereum uses an elaborated mechanism compared to Bitcoin, leading to an increase in the attack surface of their SCs. The mechanism that makes the Bitcoin script - a limited version of SCs - more secure is the ability to compute, independent of the BC's state, an upperbound on resources needed to execute this TX. Thus, this work proposes a new approach enabling security benefits by defining an upper-bound on resource usage for general SCs. Furthermore, the approach allows for the payment of fees in any currency and not just the native currency of the BC.
Like most programs, smart contracts offer their functionality via entry points that constitute the interface. Interface standards, e.g. for tokens contracts, foster interoperability. Ethereum is the most prominent platform for smart contracts. The number of contract deployments approaches 30 million, corresponding to roughly 300 000 distinct contract codes. In view of these numbers, it is necessary to develop automated methods for classifying contracts regarding their purpose, if one aims at a qualitative and quantitative understanding of what blockchain applications are used for at large. We approach the task by considering contracts as similar if their interfaces are. We encode interfaces and their interrelationships as graphs and explore several algorithms regarding their ability to find clusters of functionally similar contracts. Our evaluation of the quality of clustering relies on a ground truth of token and wallet contracts identified in earlier work. Our analysis is based on the bytecodes deployed on the main chain of Ethereum up to block 10.5 million, mined on July 21, 2020.
This perspective proposes that, by virtue of its sophisticated trust and consensus finding mechanisms, blockchain has the clear potential to substantially upgrade the processes and organization traditionally underpinning academic science and commercial technology development comprising funding, project delivery, generation of intellectual property, documentation and publication. For supporting this hypothesis, striking analogies between the concepts underlying blockchain technology with research are identified, and applied to the generation of verified knowledge in science and technology development. It is then elaborated how a blockchain-enabled token economy can efficiently and transparently incentivize and coordinate an integrative and community-inclusive participatory approach to fuel crowdsourcing of collective intelligence for contributing ideas, work, infrastructure, funding, data, validation, management, assessment, governance, arbitration and exploitation of projects. Quality, credibility and direction of projects are optimized by demanding collateral “skin-in-the-game” from contributors based on blockchain-enabled staking, reputation systems and prediction markets. This way research progress emerges as a chain of community generated and independently vetted blocks of scientific knowledge; these new blocks are concatenated with the state-of-the-art according to transparent consensus mechanisms.
The combination of smart contracts with blockchain technology enables the authentication of the contract and limits the risks of non-compliance. In principle, smart contracts can be processed more efficiently compared to traditional paper-based contracts. However, current smart contracts have very limited capabilities with respect to normative representations, making them too distant from actual contracts. In order to reduce this gap, the paper presents an architectural analysis to see the role of computational artifacts in terms of various ex-ante and ex-post enforcement mechanisms. The proposed framework is assessed using scenarios concerning data-sharing operations bound by legal requirements from the General Data Protection Regulation (GDPR) and data-sharing agreements.
Based on the Bitcoin exchange data, COVID-19 data, and Twitter data from January 2020 to July 2020, this paper compares the performance of four different machine learning models on predicting the Bitcoin return rate and price trend. Data are formulated to four input feature sets, including: (1) Historical Bitcoin exchange data; (2) Historical Bitcoin exchange data + COVID-19 data (recovery, confirmed, death); (3) Historical Bitcoin exchange data + Twitter data; (4) Historical Bitcoin exchange data + COVID-19 data (recovery, confirmed, death) + Twitter data. The four machine learning models implemented are: (1) Random forest; (2) Decision tree; (3) AdaBoost; (4) Support vector machine. We found that: (1) Twitter data can improve the performance of models; (2) People consider information within 5 days when they make decisions on investments; (3) Support vector machine does not perform well in predicting Bitcoin return rate or price trend; (4) COVID-19 data does not help improve the prediction. However, we have very limited COVID-19 data, so future research with more COVID-19 data may help confirm if the last statement is correct or not.
Bitcoin is an emerging digital asset and is getting more attention in the media as of writing. Though, despite the regulatory matters, this paper is more concerned with the factors that influence the behavioral intention to use Bitcoin by the Malaysian. Although there are some recent studies on the intention and acceptance of Bitcoin, yet there is limited evidence from Malaysia. Therefore, this study intends on shedding some light on the current stance of the Malaysians on Bitcoin by examining the factors that affect the behavioral intention to use Bitcoin in Malaysia grounded on the Unified Theory of Acceptance and Use of Technology (UTAUT) model. The data was collected using an online self-administered questionnaire through the relevant local Malaysian forums and local cryptocurrency groups. The result shows that performance expectancy has the greatest influence on the users’ behavioral intention to use Bitcoin, followed by other factors such as social influence and facilitating conditions. Additional analysis of variance and moderation analyses show no significant difference in the mean of the behavioral intention between different demographic characteristics, and the interactions of the demographic characteristics and the UTAUT factors also demonstrate an insignificant effect on the behavioral intention to use Bitcoin. The result suggests that the behavioral intention to use Bitcoin by the Malaysian may increase if the use of Bitcoin can provide convenience to the public and businesses, but it is also influenced by the social and facilitating conditions. The result well reflects the main function of Bitcoin, that is as a currency and also as an investment tool. The finding echoes the effort and policies of the government of Malaysia to find an equilibrium between the use and the abuse of digital currencies as a currency, as well as the risks and returns of digital currencies as an investment tool.
스마트 컨트랙트는 분산 원장 환경에서 데이터를 기록하여 데이터의 무결성과 유효성이 검증된다는 점과 작성된 코드에 의하여 설정된 조건이 충족되면 자동으로 이행되는 특성 때문에 신뢰성을 요구하는 다양한 자동화 시스템에 적용되고 있다. 스마트 컨트랙트가 활발하게 사용되고 있는 분야 중 하나는 계약 체결과 관련된 분야이다. 하지만 블록체인이 가진 분산 원장 환경의 특성상 거래되는 데이터가 모든 네트워크 참여자들에게 공유되기 때문에 기밀성이 요구되는 데이터는 저장하지 못한다는 문제가 있다. 본 논문은 스마트 컨트랙트 기반의 계약 플랫폼에 비밀공유 기법을 이용한 계약 내용을 별도의 데이터베이스에 저장하는 방식을 적용하여 기밀성과 무결성을 보장함으로써 비대면으로 계약서를 작성하는 과정에서 신뢰성 있는 계약 체결이 가능하도록 하는 것에 궁극적 목표를 둔다.