Blockchain Papers

Henry Syahputra, Hans Weigand

No abstract is available for this record.

Hongru Yu, Haiyang Sun, Danyi Wu, Tsung-Ting Kuo

Blockchain and smart contracts (i.e., computer code that can be run on blockchain) are increasingly popular for healthcare applications. However, only very few implementations exist because of the complexity of the technologies. Although there are tutorials and reviews to introduce blockchain and smart contracts, a pragmatic comparison of such platforms is needed. In this study, we addressed practical considerations while building a healthcare blockchain and smart contract system, by (1) comparing technical features of platforms, (2) selecting three platforms, (3) constructing blockchain networks, (4) testing the blockchains, and (5) summarizing the experience and time used for implementation by students. We evaluated Ethereum, Hyperledger Fabric, and MultiChain, and confirmed that the selection of a proper platform depends on the requirements of the application. The findings of our study can accelerate the process and reduce the risk of adopting blockchain technology in biomedical and healthcare domain.

Yeray Mezquita, Diego Valdeolmillos, Alfonso González‐Briones, Javier Prieto · 5 authors

No abstract is available for this record.

Wei-Meng Lee

In Chapter 4 , you learned how to create your own private test Ethereum network using the Ethereum client – Geth. While Geth is not that difficult to use to set up an Ethereum blockchain, it still takes considerable effort to set one up. In addition, you also need to create accounts and perform mining in order to obtain Ethers so that you can use them to deploy Smart Contracts and for performing transactions.

Dianhui Mao, Fan Wang, Yalei Wang, Zhihao Hao

Smart contract applications based on Ethereum blockchain have been widely used in many fields. They are developed by professional developers using specialized programming languages like solidity. It requires high requirements on knowledge of the specialized field and the proficiency in contract programming. Thus, it is hard for normal users to design a usable smart contract based on their own demands. Most current studies about smart contracts focus on the security of coding while lack of friendly tools for users to design the specialized templates of contracts coding. This paper provides a visual and user-defined smart contract designing systems. It makes the development of domain-specific smart contracts simpler and visualization for contract users. The system implements the domain-specific features extraction about the crawled data sets of smart contract programs by TF-IDF and K-means++ clustering algorithm. Then, it achieves the automatic generation of unified basic function codes by Char-RNN (improved by LSTM) based on the domain-specific features. The system adopts Google Blockly and links the generated codes with UI controls. Finally, it provides a set of specialized templates of basic functions for users to design smart contracts by the friendly interface. It reduces the difficulty and costs of contract programming. The paper offers a case study to design contracts by users. The designed contracts were validated on the existing system to implement the food trading and traders' credit evaluation. The experimental results show that the designed smart contracts achieve good integration with the existing system and they can be deployed and compiled successfully.

Norafni Farlina Rahim, Mohammed Hariri Bakri, Siti Norbaya Yahaya

FinTech, or financial technology, is an emerging technology in financial transaction. It is disruptive technology which is changing the banking behavior for stakeholders. The thriving emergence of FinTech not only affects the conventional finance industry but also Islamic finance industry, as Islamic finance sector is also embracing FinTech as part of financial revolution. Thus, the Islamic FinTech emerges as faith-based FinTech. This is because Islamic FinTech claimed to comply with Shariah principle in their mechanism and smart contract. There is limited discussion on smart contract and Islamic FinTech and its Shariah principles. Hence, the Shariah principle in smart contract of Islamic FinTech need to be addressed. This chapter tries to delve into the smart contract concept in Islamic FinTech and Shariah principles in the mechanism. The review found that smart contract is currently in the early stage and so is Islamic FinTech. The scholars agreed that FinTech is a Maslahah (interest) to mankind's benefit. However, the smart contract is still in discussion and review.

Claire Wilson

Since 2009, more than 1600 cryptocurrencies have entered into circulation. The rapid development of the cryptocurrency market has raised questions about whether cryptocurrencies will challenge the existing order of traditional financial institutions. Opinion remains divided. Some commentators predict that they will cause massive disruptions to the current financial system. Others claim that they are unlikely to represent the “future of money”. Opponents have expressed concern over the association between cryptocurrencies and serious crimes, resemblance to Ponzi-schemes and the increasing incidence of crypto-scams. Supporters advocate that they offer a revolutionary system of payment, an alternative investment method or an alternative means of raising funds. The legal treatment of cryptocurrencies is, however, one of the most decisive factors that will determine their future. Currently, there is no governmental consensus on how, or if, cryptocurrencies should be regulated. Some governments are issuing outright bans on specific cryptocurrency activity; others are taking positive steps by introducing legislation to legitimize their use; the remainder are undecided whether to act or not. The methodology adopted in this research is a simple SWOT analysis to assess the durability and competitive positioning of cryptocurrencies. This chapter concludes that cryptocurrencies will cause disruptions to the future of money. It is expected that they will become a permanent new institution; however, they will be far more advanced than the current generation, be heavily governed by regulation and are likely to be state-issued.

Klaus Grobys, Niranjan Sapkota

We examine all available 146 Proof-of-Work-based cryptocurrencies that started trading prior to the end of 2014 and track their performance until December 2018. We find that about 60% of those cryptocurrencies were eventually in default. The substantial sums of money involved mean those bankruptcies will have an enormous societal impact. Employing cryptocurrency-specific data, we estimate a model based on linear discriminant analysis to predict such defaults. Our model is capable of explaining 87% of cryptocurrency bankruptcies after only one month of trading and could serve as a screening tool for investors keen to boost overall portfolio performance and avoid investing in unreliable cryptocurrencies.

Usman W. Chohan

No abstract is available for this record.

Thomas Conlon, Richard McGee

No abstract is available for this record.

Denis Kirillov, Oleg Iakushkin, Vladimir Korkhov, Vadim Petrunin

No abstract is available for this record.

Yingli Wang, Catherine Huirong Chen, Ahmed Zghari-Sales

While blockchain technologies are gaining momentum within supply chains, academic understanding of concrete, real-life design and implementation is still lagging, hence offering very limited insights into the true implications of blockchain technology on supply chains. This paper reports a two-year design science research (DSR) study of a smart contract initiative piloted by a consortium in the UK’s construction sector. We seek answers to the research question, ‘How should a blockchain enabled supply chain be designed?’ Guided by the theory of business model, we explore how a group of supply chain actors collectively designs and pilots a blockchain solution that addresses the supply chain transparency and provenance problem. Our research is one of the very few longitudinal empirical studies to offer in-depth evidence about how blockchain is deployed in complex multi-tier supply chain networks. In compliance with DSR research paradigm, we make contributions at three levels: designing and instantiating the blockchain architect and proving its utility in addressing the target problem; developing a set of design principles as a mid-range theory that can be applied and tested in different blockchain supply chain contexts; and refining and extending the kernel theory of business value at supply chain network level.

Wei-Meng Lee

In the previous chapters, you have learned the basics of Smart Contracts and how to deploy them onto the blockchain. So far, all interactions with the Smart Contracts have been through the Remix IDE. While the Remix IDE provides an easy way for developers to test their Smart Contracts, it is not suitable for use by end users. To allow end users to interact with your Smart Contracts, you need to build front end that hides the complexity of interacting with the Smart Contracts in the back end. For this purpose, you need an API.

Gregor Dorfleitner, Diana Braun

No abstract is available for this record.

Jiri Chod, Nikolaos Trichakis, S. Alex Yang

No abstract is available for this record.

Cameron Harwick, James Caton

Despite the past decade’s rapid innovation in adapting blockchain technology to new uses, financial intermediation remains elusive except in basic and highly collateralized forms. We introduce the concept of the technical frontier to delimit the kinds of interactions that can feasibly be structured algorithmically among pseudonymous agents, as on a blockchain, and show that lending and financial intermediation – unlike monetary exchange – lie outside it, even in simple forms. The path forward for truly blockchain-native financial applications, therefore, must involve the integration of real-world identity information in order to disincentivize defection. We discuss several potential technologies for doing so, and conclude that such integration is possible without compromising pseudonymity, provided real-world identity is available in the breach.

Yan Chen

No abstract is available for this record.

Daniel Hellwig, Goran Karlic, Arnd Huchzermeier

Decentralized finance has evolved as a major contender for traditional banking systems over the last few years. Evolution in blockchain and cryptography technologies are the driving forces for decentralized finance’s growth. The emergence of Bitcoin in the finance system was a major driving force toward the tremendous growth of decentralized finance. However, with various platforms merging every day, the decentralized finance sector is still in its early, unorganized stages. The current decentralized finance market is chaotic. With a new “coin” being introduced almost every month, standardization is highly lacking in the system. DeFi already has several different applications available. For instance, one can purchase stable coins, or assets pegged to a national currency, on decentralized exchanges, move the assets to a lending platform that is also decentralized to earn interest, and then add the interest-earning instruments to a decentralized liquidity pool or an on-chain investment fund. DeFi enterprises frequently aim at decentralized decision-making, or governance, in everything from the user fees to the products they provide. A decentralized program may be started by one person or a small number of individuals, but as the project gathers traction, its leaders frequently try to step down and cede control to the user base. A decentralized autonomous organization that has its rules and regulations written into computer code and that may issue governance tokens, which allow its holders a voice in decisions rather than allowing the decision-making to a centralized government authority as in case of traditional finance, could represent this transition. While on one side, world governments are still trying to grasp and regulate the sector, on the other side, the technology’s reach has been very limited. Undoubtedly, the emergence of blockchain-based decentralized finance is massively influencing our current finance technology industry. In this chapter, we discuss the current growth in the FinTech industry and the blockchain-based decentralized finance sector. Furthermore, we discuss how decentralized finance can be used in the current FinTech industry.

Shuai Wang, Chenchen Huang, Juanjuan Li, Yong Yuan · 5 authors

Since first coined by Google in 2012, knowledge graph has received extensive attention from both industry and academia, and has been widely used in many scenarios with success, e.g. information retrieval, online recommendation, question-answering, and so on. However, traditional centralized construction of knowledge graph faces many challenges, such as laborious and time-consuming, vulnerable to manipulation or tampering, lacking scrutiny, among others. Therefore, in this paper, we propose a novel decentralized knowledge graph construction method by means of crowdsourcing, and the business logic of crowdsourcing is implemented by blockchain-powered smart contracts to guarantee the transparency, integrity, and auditability. On this basis, the decentralized knowledge graph is used for a deep recommender system, and case studies validate the effectiveness of the system. This paper is aimed at providing a novel decentralized approach for constructing knowledge graph and serving as reference and guidance for future research and practical applications of knowledge graph.

Jan Ladleif, Mathias Weske

No abstract is available for this record.

Wolfgang Ahrendt, Richard Bubel, Joshua Ellul, Gordon J. Pace · 7 authors

No abstract is available for this record.

Joshua S. Gans

One of the purported benefits of blockchain technologies is the ability to house what have been termed ‘smart’ contracts. Such contracts are potentially self-executing depending on the state of information recorded on a blockchain ledger. This paper examines the capabilities of smart contracts from an economic perspective. It is demonstrated that by improving observability and reducing the costs of verification of contract obligation performance, the space of feasible contracts can be enlarged. Moreover, by providing commitments to various monetary payments, a blockchain can potentially create a foundation to house certain mechanisms that have been shown to overcome difficulties of contractual incompleteness. This is demonstrated using a simple international trade environment. Thus, even though smart contracts must respect the incentives of decision-makers in their obligations, they have the potential to use easily verifiable elements to create incentives to reduce hold-up and other contractual difficulties.

Jens Frankenreiter

This essay investigates the potential of smart contracts to replace the legal system as an infrastructure for transactions. It argues that (contract) law remains relevant for most transactions even if they are entirely structured by way of smart contract. The reason for this is that the power of smart contracts to create and enforce obligations against attempts by the legal system to thwart their execution is limited. These limitations are most relevant for obligations to perform certain actions outside the blockchain, but also apply to other obligations contingent on facts outside the records stored on the blockchain.

Ngoc Tien Thanh Le, Quoc Nghiep, Nguyen Ngoc, Nghia Duong‐Trung · 7 authors

The adoption of decentralized cryptocurrency plat-forms is growing fast, thanks to the implementation of Blockchain technology and smart contracts. It encourages the novel frame-works in a wide range of applications including finance and payment methods such as cash on delivery. However, a large number of smart contracts developed for cash on delivery suffer from fraudulent transactions which enable malicious participants to break the signed contracts without sufficient penalties. A shipper will involve in the system and place a mortgage to ensure reliability. A buyer also pledges an amount of money when making the order. Our process not only ensures the interests of a seller but also prevents a fraud shipper. The penalties will be made in two scenarios: (i) the buyer refuses to receive the commodities without any reliable reasons; and (ii) the shipper attempts to make any modification on the delivered goods during transportation. To help developers create more secure and reliable cash on delivery system, we introduce double smart contracts, a framework rooted in Blockchain technology and Ethereum, to tackle those mentioned problems. We also contribute our solution as an open source software that developers can easily add to their implementation to enhance functionality.