Blockchain Papers

Yang Lu

The prosperity of Bitcoin has given rise to widespread attention and in-depth research on blockchains. The blockchain provides the fundamental technology for the decentralization, openness, security, independence, anonymity, integrity, and authenticity of diversified applications. The literature selected are mainly from IEEE papers and conference proceedings. This paper deeply analyzes the basic features and categories of blockchain and delineates the practical applications. The aim is to find the development prospects of blockchains through analysis of existing applications and technologies.

Juan Guarnizo, Paweł Szałachowski

Smart contracts are a new paradigm that emerged with the rise of the blockchain technology. They allow untrusting parties to arrange agreements. These agreements are encoded as a programming language code and deployed on a blockchain platform, where all participants execute them and maintain their state. Smart contracts are promising since they are automated and decentralized, thus limiting the involvement of third trusted parties, and can contain monetary transfers. Due to these features, many people believe that smart contracts will revolutionize the way we think of distributed applications, information sharing, financial services, and infrastructures. To release the potential of smart contracts, it is necessary to connect the contracts with the outside world, such that they can understand and use information from other infrastructures. For instance, smart contracts would greatly benefit when they have access to web content. However, there are many challenges associated with realizing such a system, and despite the existence of many proposals, no solution is secure, provides easily-parsable data, introduces small overheads, and is easy to deploy. In this paper we propose PDFS, a practical system for data feeds that combines the advantages of the previous schemes and introduces new functionalities. PDFS extends content providers by including new features for data transparency and consistency validations. This combination provides multiple benefits like content which is easy to parse and efficient authenticity verification without breaking natural trust chains. PDFS keeps content providers auditable, mitigates their malicious activities (like data modification or censorship), and allows them to create a new business model. We show how PDFS is integrated with existing web services, report on a PDFS implementation and present results from conducted case studies and experiments.

Mengting Liu, F. Richard Yu, Yinglei Teng, Victor C. M. Leung · 5 authors

Blockchain technology has been applied in a variety of fields due to its capability of establishing trust in a decentralized fashion. However, the application of blockchain in wireless mobile networks is hindered by a major challenge brought by the proof-of-work puzzle during the mining process, which sets a high demand for the computational capability and storage availability in mobile devices. To address this problem, we propose a novel mobile edge computing (MEC) enabled wireless blockchain framework where the computation-intensive mining tasks can be offloaded to nearby edge computing nodes and the cryptographic hashes of blocks can be cached in the MEC server. Particularly, two offloading modes are considered, i.e., offloaded to the nearby access point or a group of nearby users. First, we conduct the performance analysis of each mode with stochastic geometry methods. Then, the joint offloading decision and caching strategy is formulated as an optimization problem. Furthermore, an alternating direction method of multipliers based algorithm is utilized to solve the problem in a distributed manner. Finally, simulation results demonstrate the effectiveness of our proposed scheme.

Han Liu, Chao Liu, Wenqi Zhao, Yu Jiang · 5 authors

Smart contracts, as a promising and powerful application on the Ethereum blockchain, have been growing rapidly in the past few years. Since they are highly vulnerable to different forms of attacks, their security becomes a top priority. However, existing security auditing techniques are either limited in fnding vulnerabilities (rely on pre-defned bug paterns) or very expensive (rely on program analysis), thus are insufcient for Ethereum.

Xuanwu Yue, Xinhuan Shu, Xinyu Zhu, Xinnan Du · 7 authors

The emerging prosperity of cryptocurrencies, such as Bitcoin, has come into the spotlight during the past few years. Cryptocurrency exchanges, which act as the gateway to this world, now play a dominant role in the circulation of Bitcoin. Thus, delving into the analysis of the transaction patterns of exchanges can shed light on the evolution and trends in the Bitcoin market, and participants can gain hints for identifying credible exchanges as well. Not only Bitcoin practitioners but also researchers in the financial domains are interested in the business intelligence behind the curtain. However, the task of multiple exchanges exploration and comparisons has been limited owing to the lack of efficient tools. Previous methods of visualizing Bitcoin data have mainly concentrated on tracking suspicious transaction logs, but it is cumbersome to analyze exchanges and their relationships with existing tools and methods. In this paper, we present BitExTract, an interactive visual analytics system, which, to the best of our knowledge, is the first attempt to explore the evolutionary transaction patterns of Bitcoin exchanges from two perspectives, namely, exchange versus exchange and exchange versus client. In particular, BitExTract summarizes the evolution of the Bitcoin market by observing the transactions between exchanges over time via a massive sequence view. A node-link diagram with ego-centered views depicts the trading network of exchanges and their temporal transaction distribution. Moreover, BitExTract embeds multiple parallel bars on a timeline to examine and compare the evolution patterns of transactions between different exchanges. Three case studies with novel insights demonstrate the effectiveness and usability of our system.

Maria Apostolaki, Gian Marti, Jan Müller, Laurent Vanbever

Routing attacks remain practically effective in the Internet today as existing countermeasures either fail to provide protection guarantees or are not easily deployable. Blockchain systems are particularly vulnerable to such attacks as they rely on Internet-wide communication to reach consensus. In particular, Bitcoin -the most widely-used cryptocurrency- can be split in half by any AS-level adversary using BGP hijacking. In this paper, we present SABRE, a secure and scalable Bitcoin relay network which relays blocks worldwide through a set of connections that are resilient to routing attacks. SABRE runs alongside the existing peer-to-peer network and is easily deployable. As a critical system, SABRE design is highly resilient and can efficiently handle high bandwidth loads, including Denial of Service attacks. We built SABRE around two key technical insights. First, we leverage fundamental properties of inter-domain routing (BGP) policies to host relay nodes: (i) in locations that are inherently protected against routing attacks; and (ii) on paths that are economically preferred by the majority of Bitcoin clients. These properties are generic and can be used to protect other Blockchain-based systems. Second, we leverage the fact that relaying blocks is communication-heavy, not computation-heavy. This enables us to offload most of the relay operations to programmable network hardware (using the P4 programming language). Thanks to this hardware/software co-design, SABRE nodes operate seamlessly under high load while mitigating the effects of malicious clients. We present a complete implementation of SABRE together with an extensive evaluation. Our results demonstrate that SABRE is effective at securing Bitcoin against routing attacks, even with deployments as small as 6 nodes.

Pietro Tedeschi, Giuseppe Piro, Jose Antonio Sanchez Murillo, Nemanja Ignjatov · 7 authors

Blockchain is emerging as a promising technology that is able to support transparent, secure, and immutable transactions traceability in decentralized networks. Its usage in many application domains, including the Internet of Things, is gaining the attention of even more researchers and industries worldwide. In line with current research interests, the work presented in this letter has been carried out in the context of the European H2020 symbIoTe project. Among its main features, the symbIoTe framework offers bartering functionalities across a federation of Internet of Things platforms. This letter extends the baseline implementation of bartering functionalities and formulates a novel methodology that properly integrates and takes advantages from the Blockchain technology. Even if the proposed approach is general, the main facets characterizing the conceived approach are illustrated through a fictional use case envisaging the provisioning of Intelligent Transportation System and air pollution services in a Smart City.

Christian Kaiser, Marco Steger, Ali Dorri, Andreas Festl · 7 authors

No abstract is available for this record.

Obryan Poyser

No abstract is available for this record.

Reney Henderson, Michael Mazzeffi, Kenichi A. Tanaka

Uncertainty is a common theme in economics and clinical medicine. Federal currency and most recently cryptocurrency have gone up and down due to regional and global speculation in the market. Medication can also gain momentum for clinical use after a single successful clinical trial, but its true efficacy or safety gets refuted in later trials. Such examples were recently observed with aprotinin (Aprotinin; Bayer, West Haven, CT) and activated protein C (Xigris; Eli Lilly, Indianapolis, IN), leading both to market withdrawal in 2007 and 2011, respectively.1,2 Human plasma-derived fibrinogen concentrate (hFC) has certainly gone through a volatile history since it was originally approved by the US Food and Drug Administration (FDA) in 1947.3 Clinical use of hFC quickly spread,4 but it ended up with a license withdrawal by the FDA in 1977 due to widespread viral infections, particularly hepatitis C around the globe.3,5 Pathogen-reduced hFC for intravenous use has been available in certain countries since 1985,4 but a resurgence of hFC took place in the United States as a topical fibrin sealant in 1998.6 The hFC (RiaStap; CSL Behring, Marburg, Germany) was finally approved by the FDA in 2009 for the indications in hereditary afibrinogenemia or hypofibrinogenemia.4 In this month’s Anesthesia & Analgesia, Li et al7 performed a meta-analysis of 8 randomized controlled trials (RCTs) of hFC. The authors aimed to analyze the overall impact(s) of its prophylactic use on morbidity and/or mortality after cardiac surgery using cardiopulmonary bypass (CPB). Hemostasis management often poses a challenge to anesthesiologists and intensivists, and thus a meta-analysis such as this can provide a summary of existing literature and point to a direction for future clinical trials. However, clinician readers too often accept meta-analyses as definitive without fully appreciating their limitations, particularly heterogeneity among the studies.8 Clinical heterogeneity may be particularly important in the valuation of meta-analysis output as discussed below. The title of this analysis states “prophylactic fibrinogen concentrate use,” but only 3 studies adopted “prophylactic” dosing before CPB,9–11 and 1 used it prophylactically without bleeding according to thromboelastometry (TEM) criteria after CPB (Table).14 In the other 4 studies,12,13,15,16 hFC was given for clinically observed bleeding. Prolonged CPB lasting >2 hours increases heterogeneity of coagulopathy,18 and hFC pre-CPB may be insufficient to treat multifactorial coagulation defects. Indeed, only 2 RCTs utilized TEM to evaluate reduced thrombin generation,9,14 and others used TEM only for research purposes11,15 or for hFC dosing.13,16 The randomized evaluation of fibrinogen versus placebo in complex cardiovascular surgery (REPLACE) study by Rahe-Meyer et al13 is the largest and only multicenter hFC trial focused on high-risk thoracic aortic replacement to date, which warrants further discussion (Table). The authors utilized 60–250 g increase in surgical sponge weight over 5 minutes as an inclusion criterion, assuming that >250 g indicated macrovascular bleeding. In the REPLACE study, 322 of 519 randomized patients (62.0%) were excluded after CPB based on the 5-minute bleeding assessment. Only 18.8% (15 of 80) were excluded in the original single-center hFC trial by Rahe-Meyer et al.16 The exclusion of large numbers of patients after randomization might have biased the study results, and it clearly indicates high heterogeneity of patients and coagulopathy after prolonged CPB.12,13,15Table.: Characteristics of the Fibrinogen Treatment Group From 8 Randomized Clinical TrialsThus, do we have to remain uncertain about the use of hFC in complex cardiac surgical cases based on the finding of Li et al?7 The answer may not lie in a global multicenter trial but may be found in the regional practice. First, if alternative fibrinogen replacement (cryoprecipitate) is unavailable or if a viral endemic again becomes rampant, hFC with virucidal treatment can be a safer alternative to multiunit allogeneic plasma transfusion.4,19 Second, RCTs that tested multimodal coagulation therapies, including hFC guided by TEM, have demonstrated more rapid reversal of coagulopathy and lower incidence of massive transfusion compared to the conventional therapy using plasma transfusion in cardiac surgery19 and acute trauma resuscitation.20 Third, frozen plasma and cryoprecipitate needs to be thawed and used in a timely fashion (otherwise wasted). The hFC can be stored for ≤30 months at temperatures of 2°C–25°C and reconstituted on demand, which might lead to better resource utilization. Clinicians need to understand such heterogeneity of clinical practice around the globe and make the best of available resources. There are collaborative efforts to standardize reported end points in perioperative RCTs and to foster data sharing.21 Future meta-analysis can benefit from such efforts as they delineate more information on methodological and clinical heterogeneity. In conclusion, hFC may not yet be the global currency of perioperative bleeding management, but it is certainly an attractive option when used in the right clinical context. DISCLOSURES Name: Reney A. Henderson, MD. Contribution: This author helped write the editorial and approved the final manuscript. Name: Michael A. Mazzeffi, MD, MPH. Contribution: This author helped write the editorial and approved the final manuscript. Name: Kenichi A. Tanaka, MD, MSc. Contribution: This author helped write the editorial and approved the final manuscript. This manuscript was handled by: Honorio T. Benzon, MD.

Miguel‐Ángel Sicilia, Anna Visvizi

Purpose The purpose of this paper is to employ the case of Organization for Economic Cooperation and Development (OECD) data repositories to examine the potential of blockchain technology in the context of addressing basic contemporary societal concerns, such as transparency, accountability and trust in the policymaking process. Current approaches to sharing data employ standardized metadata, in which the provider of the service is assumed to be a trusted party. However, derived data, analytic processes or links from policies, are in many cases not shared in the same form, thus breaking the provenance trace and making the repetition of analysis conducted in the past difficult. Similarly, it becomes tricky to test whether certain conditions justifying policies implemented still apply. A higher level of reuse would require a decentralized approach to sharing both data and analytic scripts and software. This could be supported by a combination of blockchain and decentralized file system technology. Design/methodology/approach The findings presented in this paper have been derived from an analysis of a case study, i.e., analytics using data made available by the OECD. The set of data the OECD provides is vast and is used broadly. The argument is structured as follows. First, current issues and topics shaping the debate on blockchain are outlined. Then, a redefinition of the main artifacts on which some simple or convoluted analytic results are based is revised for some concrete purposes. The requirements on provenance, trust and repeatability are discussed with regards to the architecture proposed, and a proof of concept using smart contracts is used for reasoning on relevant scenarios. Findings A combination of decentralized file systems and an open blockchain such as Ethereum supporting smart contracts can ascertain that the set of artifacts used for the analytics is shared. This enables the sequence underlying the successive stages of research and/or policymaking to be preserved. This suggests that, in turn, and ex post , it becomes possible to test whether evidence supporting certain findings and/or policy decisions still hold. Moreover, unlike traditional databases, blockchain technology makes it possible that immutable records can be stored. This means that the artifacts can be used for further exploitation or repetition of results. In practical terms, the use of blockchain technology creates the opportunity to enhance the evidence-based approach to policy design and policy recommendations that the OECD fosters. That is, it might enable the stakeholders not only to use the data available in the OECD repositories but also to assess corrections to a given policy strategy or modify its scope. Research limitations/implications Blockchains and related technologies are still maturing, and several questions related to their use and potential remain underexplored. Several issues require particular consideration in future research, including anonymity, scalability and stability of the data repository. This research took as example OECD data repositories, precisely to make the point that more research and more dialogue between the research and policymaking community is needed to embrace the challenges and opportunities blockchain technology generates. Several questions that this research prompts have not been addressed. For instance, the question of how the sharing economy concept for the specifics of the case could be employed in the context of blockchain has not been dealt with. Practical implications The practical implications of the research presented here can be summarized in two ways. On the one hand, by suggesting how a combination of decentralized file systems and an open blockchain, such as Ethereum supporting smart contracts, can ascertain that artifacts are shared, this paper paves the way toward a discussion on how to make this approach and solution reality. The approach and architecture proposed in this paper would provide a way to increase the scope of the reuse of statistical data and results and thus would improve the effectiveness of decision making as well as the transparency of the evidence supporting policy. Social implications Decentralizing analytic artifacts will add to existing open data practices an additional layer of benefits for different actors, including but not limited to policymakers, journalists, analysts and/or researchers without the need to establish centrally managed institutions. Moreover, due to the degree of decentralization and absence of a single-entry point, the vulnerability of data repositories to cyberthreats might be reduced. Simultaneously, by ensuring that artifacts derived from data based in those distributed depositories are made immutable therein, full reproducibility of conclusions concerning the data is possible. In the field of data-driven policymaking processes, it might allow policymakers to devise more accurate ways of addressing pressing issues and challenges. Originality/value This paper offers the first blueprint of a form of sharing that complements open data practices with the decentralized approach of blockchain and decentralized file systems. The case of OECD data repositories is used to highlight that while data storing is important, the real added value of blockchain technology rests in the possible change on how we use the data and data sets in the repositories. It would eventually enable a more transparent and actionable approach to linking policy up with the supporting evidence. From a different angle, throughout the paper the case is made that rather than simply data, artifacts from conducted analyses should be made persistent in a blockchain. What is at stake is the full reproducibility of conclusions based on a given set of data, coupled with the possibility of ex post testing the validity of the assumptions and evidence underlying those conclusions.

Jiaqi Liang, Linjing Li, Daniel Zeng

Cryptocurrency is a well-developed blockchain technology application that is currently a heated topic throughout the world. The public availability of transaction histories offers an opportunity to analyze and compare different cryptocurrencies. In this paper, we present a dynamic network analysis of three representative blockchain-based cryptocurrencies: Bitcoin, Ethereum, and Namecoin. By analyzing the accumulated network growth, we find that, unlike most other networks, these cryptocurrency networks do not always densify over time, and they are changing all the time with relatively low node and edge repetition ratios. Therefore, we then construct separate networks on a monthly basis, trace the changes of typical network characteristics (including degree distribution, degree assortativity, clustering coefficient, and the largest connected component) over time, and compare the three. We find that the degree distribution of these monthly transaction networks cannot be well fitted by the famous power-law distribution, at the same time, different currency still has different network properties, e.g., both Bitcoin and Ethereum networks are heavy-tailed with disassortative mixing, however, only the former can be treated as a small world. These network properties reflect the evolutionary characteristics and competitive power of these three cryptocurrencies and provide a foundation for future research.

Kathy Ning Shen, Valerie Lindsay, Yunjie Xu

The rapid proliferation of digital technologies with new functionalities has profoundly changed competitive environments, reshaping traditional business strategies and processes (Bharadwaj, Sawy, Pavlou, & Venkatraman, 2013). Such technologies also give rise to new ways of collaboration, leveraging resources, product/service design, development, and deployment over open standards and shared technologies (Markus & Loebecke, 2013). At the microlevel, digital technologies also reshaped the mentality of entrepreneurs (Domenico, Daniel, & Nunan, 2014) and hence affect their decision-making processes (Shepherd, Williams, & Patzelt, 2014). Digital entrepreneurship includes ventures and transformation of existing businesses by creating novel digital technologies and/or novel usage of such technologies. Currently, many countries consider digital entrepreneurship as a critical pillar for digital economic development. It is imperative to develop a fine-grained understanding of digital entrepreneurship. Traditionally, research on entrepreneurship seeks to understand “how, by whom, and with what effects opportunities to create future goods and services are discovered, evaluated, and exploited” (Shane & Venkataraman, 2000) and how entrepreneurial activities, processes, and outcomes are influenced by certain contexts (Zahra, Wright, & Abdelgawad, 2014). Despite the increasing numbers of entrepreneurs and businesses that are currently using digital technologies to pursue opportunities, research has lagged far behind practice and paid limited attention to the phenomenon (Grégoire & Shepherd, 2012). Particularly, the understanding about the role that digital technologies play in entrepreneurship and the role that users and agents play in digital entrepreneurship remains limited (Nambisan, 2016). Several review articles on entrepreneurship also clearly point out the gaps in understanding the novel usage of digital technologies by entrepreneurs (Kiss, Danis, & Cavusgil, 2012; Mainela, Puhakka, & Servais, 2014; Shepherd et al., 2014). Research in the IS field has a relatively long tradition of investigating entrepreneurial actions enabled by digital technologies within an organizational context (Bharadwaj et al., 2013; Sambamurthy, Bharadwaj, & Grover, 2003). However, only a few recent studies have shed light on the characteristics and design of digital platforms for entrepreneurial activities, such as crowdfunding (Burtch, 2013; Burtch, 2014; Zheng, Li, Wu, & Xu, 2014). The objective of this special issue is to provide a forum for IS and other business scholars to engage in this important dialogue on digital entrepreneurship and to contribute to the development of cumulative knowledge in this pivotal area. The selected articles address digital entrepreneurship from quite diversified perspectives with different methodologies and shed light on the roles of technologies. In particular, these studies reveal some interesting interactions among platforms, players, institutions, and agency and offer rich insights to guide future research on digital entrepreneurship. The study on “Digital Transformation by SME Entrepreneurs: A Capability Perspective” by Li, Su, Zhang, and Mao (2018) offers a special perspective to understand the transformation of SMEs in a digital ecosystem. This paper presents case studies that describe how seven SMEs have transformed from local, incapable small firms to active and successful cross-border e-commerce (CBEC) players on the Alibaba platform. From the authors' view, these Chinese firms were “least likely to embrace IT and complex digital platforms for foreign trade.” The miracle happened through dynamic managerial capability building, organization capability building for CBEC, and strategic changes. A key perspective to appreciate the paper is its exposition on how SMEs acquire capabilities through the Alibaba digital platform. While the authors rightfully focus on SMEs' acquisition of capabilities necessary for CBEC and beyond, a reader may as well appreciate how a digital platform plays a nurturing role in this process. Almost at every step, the platform goes the extra mile in motivating SMEs, providing hands-on training on the use of the platform, providing social networking and mutual learning among SMEs, building CBEC tools to overcome trading barriers, and motivating SMEs for strategic transformation. Therefore, the moral of the story is really not only about how individual SMEs became heroically successful but also about what a platform should do to build a digital ecosystem, with CBEC being an example. The authors call it the “management-oriented service” of the platform, which could be interpreted as the “nurturing,” “coaching,” and “scaffolding” roles of the platform. The intricate relationship between the platform and SMEs is what makes this case study different. A plausible explanation of this phenomenon is the Chinese business culture on relationships or “guanxi.” If so, this study offers an interesting contrast to the typical arms-length business relationship that exists between firms and a platform in the West. The paper, “From a Marketplace of Electronics to a Digital Entrepreneurial Ecosystem (DEE): The Emergence of a Meta-Organization in Zhongguancun, China,” by Du, Pan, Zhou, and Ouyang (2018), focuses on the digital entrepreneurial ecosystem (DEE) and, particularly, the role of the external environment, using a case-based approach. The paper reports on the findings from a single case study of an emerging DEE in China, often referred to as “China's Silicon Valley.” Meta-organizational theory is used to show that the emergence of the DEE involves the development of a meta-organization or “community.” The meta-organization comprises elements of labour (institutional supporters, coworking space operators, and niche players) and integration effort, which is concerned with the construction of a common infrastructure and the cultivation of an entrepreneurial culture. The study adds to the literature by providing a rich account of the emergence of a DEE and showing the importance of taking a community perspective in examining how the actors involved organize to exploit the entrepreneurial opportunities available through digital technologies. Given that much of the research on digital entrepreneurship is at the single firm level, this study makes an important contribution by examining the ecosystem and the meta-organization formation process. This provides a richly grounded basis for guiding entrepreneurs on the dynamics of a DEE and the roles and processes involved. Sometimes, digital platforms may pose negative challenges to heterogeneous entrepreneurship. The stigma of a digital platform is one of such challenges that might affect entrepreneurs and their ventures on the platform. The study by Ingram Bogusz and Morisse (2018), entitled “How Infrastructures Anchor Open Entrepreneurship: The Case of Bitcoin and Stigma,” brings a fresh perspective to understand the relational aspects of digital platforms by using an ideological lens to examine how a digital platform (in this case bitcoin infrastructure) is described and interpreted by open entrepreneurs and how such ideologically heterogeneous entrepreneurship responds to stigma towards bitcoin communities. The authors used a case study of the bitcoin community and entrepreneurs to reveal the possible ideologies held by entrepreneurs over bitcoin communities, ranging from mainstream, pragmatist, technologist to libertarian. Entrepreneurs with different ideologies develop different interpretations of the stigma towards bitcoin communities and hence respond in different ways. Financing is a critical issue for entrepreneurship, and crowdfunding offers a novel approach. Two papers in this special issue provide interesting and supplementary insight. The paper entitled “Sponsor's Cocreation and Psychological Ownership in Reward-based Crowdfunding” by Zheng, Xu, Zhang, and Wang (2018) addresses the topic of online reward-based crowdfunding. The study draws on data from a sample of individual crowdfunding investors in China. It focuses on how the sponsor's psychological ownership of the entrepreneurial project is promoted by their value cocreation process and leads to an improvement of the sponsor-entrepreneur relationship and commitment. Sponsor's cocreation positively influences psychological ownership by generating perceptions of control and intimate knowing about the project, which the authors showed as important mediators of the relationship. The study found that the relationship between sponsor cocreation and psychological ownership was moderated by the entrepreneur's activeness, as well as by social connections, implying that active involvement of the entrepreneur and sharing of information were important factors in enhancing the relationship. The paper makes an important contribution to a so-far neglected area of reward-based crowdfunding research by focusing on the postinvestment behaviours and relationships of sponsors and entrepreneur. By considering the role of sponsor cocreation on the relationship and the sponsor's ongoing commitment to the project, the paper provides useful insights into the psychological and behavioural dimensions associated with reward-based crowdfunding. The study by Thies, Wessel, and Benlian (2018), entitled “Network Effects on Crowdfunding Platforms: Exploring the Implications of Relaxing Input Control,” sheds light on the mechanisms that drive the evolution and growth of a crowdfunding platform. Using 8-year data from one of the most popular reward-based crowdfunding platforms, Kickstarter, the authors seek to answer whether, in such digital platforms, the platform growth is mainly driven by funders, entrepreneurial projects, or their reciprocal relationship. The findings suggest asymmetric network effects, in that increasing the number of entrepreneurial projects, as compared with the number of funders, contributes more to network effects and is more critical for platform growth. Hence, should losing input control, one of the mechanisms to increase the number of entrepreneurial projects, be a reasonable choice? The results show that both same-side and cross-side network effects would be compromised. The value in this research is to offer a useful way to understand the dynamics in digital platforms resulting from network structures. The selected articles investigate quite a diversified yet related set of phenomena in digital entrepreneurship and reveal the rich interaction among digital platforms, entrepreneurs, institutions, and investors. We believe these studies add great value to enrich our understanding of digital entrepreneurship and hope the exploration effort made by the authors in this special issue will inspire future research developments. Dr Kathy Ning Shen is an Associate Professor in the Faculty of Business and Management at the University of Wollongong in Dubai. She received her Doctoral degree in Information Systems from the City University of Hong Kong and was the Chairperson of the Management Information System Department at Abu Dhabi University. Her main research areas include human-computer interaction, applications of information systems in organizations, e-marketing, virtual communities, and knowledge management. She has published more than 60 refereed journal and conference articles. Her work has appeared in top refereed journals such as Journal of the American Society for Information Science and Technology, Information & Management, Journal of Business Research, Communications of the ACM, Behaviour and Information Technology, Journal of Computer Information Systems, and Internet Research and top conferences in the field. Professor Valerie Lindsay is Professor of Entrepreneurship and Management, and Director of Graduate Programs (SBA) at the American University of Sharjah (AUS) in the UAE. She has a PhD from the University of Warwick in the UK. Prior to joining AUS, she was the Dean of the Faculty of Business at the University of Wollongong in Dubai, held academic positions at the Victoria University of Wellington, New Zealand, the University of Auckland, New Zealand, and at the University of Warwick, UK, specializing in international business and strategy. Professor Lindsay's research interests lie in the area of international strategy, specifically, internationalization and market entry, SMEs, services internationalization, and business in Asia. Her work has been published in leading journals, including Management International Review, Organizational Dynamics, Industrial Marketing Management, and International Journal of Services Industry Marketing, and she coauthored the book Knowledge at Work. Before joining academia, Valerie was the New Zealand Marketing Manager for ICI Pharmaceuticals and also worked in two New Zealand government departments in the areas of trade and tertiary education. She has consulted widely in strategy and marketing in industry and in government over many years. Professor Yunjie (Calvin) Xu is a Professor at the School of Management, Fudan University, Shanghai, China. He received his PhD in Management Information Systems from Syracuse University, New York, USA. His research interests include electronic commerce, knowledge management, and social media. His research publications appeared in various information systems journals, including Journal of Management Information Systems, Journal of Association for Information Systems, Journal of the American Society for Information Science and Technology, IEEE Transactions on Professional Communication, Communication of the ACM, International Journal of Electronic Commerce, Journal of Retailing, and Decision Support Systems.

Tobias Riasanow, Fiona Burckhardt, David Soto Setzke, Markus Böhm · 5 authors

The emergence of blockchain technology, most known due to the hype around Bitcoin, has the potential to transform entire industries, such as banking, insurance, or the Internet of Things (IoT). Yet, parallel ecosystems like cryptocurrencies that substitute products and services of traditional financial institutions emerged. However, literature does not provide a structured overview of the blockchain ecosystem. By analyzing 479 blockchain companies reported in the Crunchbase database, this paper visualizes the current blockchain ecosystem using the e3-value method consisting of eleven generic roles. Moreover, we identify three strategic implications where blockchain is fundamentally different from prior approaches: governance, trust, and openness. Scholars can apply the generic ecosystem for future research, while practitioners can use the model to identify possible disruptive actors or potential business opportunities.

Nallapaneni Manoj Kumar

This paper reports on how the technology behind cryptocurrency (Bitcoin) i.e. Blockchain could offer its services in distributed energy system (DES), noting on the issues related to operating conditions, energy generation monitoring, energy sharing and trading, financial flows, emission inventory, carbon emission trading and many more. Information on blockchain implication in DES is reported.

Michael L. Gagnon, Grant Stephen

Associating the health-related records and transactions of patients with their numerous “identities” as they interact with different healthcare providers, payers, pharmacy benefit managers and other entities is an expensive and complex problem. With many years of experience addressing this issue in different healthcare systems and Health Information Exchanges (HIEs), it is apparent that there is now a compelling and relatively straightforward technical solution for this problem. Presented here is a broadly feasible and technically compelling argument for a blockchain-based approach to addressing these issues. At the same time, challenges ahead and potential strategies to address them are discussed. Keywords: Blockchain; Master Patient Index; MPI; Distributed Ledger; Patient Identity; HIE; HealthInformation Exchange

Viktor Halász

The author provides an overview of how cryptocurrencies are used by criminals, and how seizing and storing can be managed in criminal investigations.

David M. Maslove, Jacob Klein, M. Kathryn Brohman, Patrick Martin

<sec> <title>BACKGROUND</title> Blockchain technology is emerging as an innovative tool in data and software security. </sec> <sec> <title>OBJECTIVE</title> This study aims to explore the role of blockchain in supporting clinical trials data management and develop a proof-of-concept implementation of a patient-facing and researcher-facing system. </sec> <sec> <title>METHODS</title> Blockchain-based Smart Contracts were built using the Ethereum platform. </sec> <sec> <title>RESULTS</title> We described BlockTrial, a system that uses a Web-based interface to allow users to run trials-related Smart Contracts on an Ethereum network. Functions allow patients to grant researchers access to their data and allow researchers to submit queries for data that are stored off chain. As a type of distributed ledger, the system generates a durable and transparent log of these and other transactions. BlockTrial could be used to increase the trustworthiness of data collected during clinical research with benefits to researchers, regulators, and drug companies alike. In addition, the system could empower patients to become more active and fully informed partners in research. </sec> <sec> <title>CONCLUSIONS</title> Blockchain technology presents an opportunity to address some of the common threats to the integrity of data collected in clinical trials and ensure that the analysis of these data comply with prespecified plans. Further technical work is needed to add additional functions. Policies must be developed to determine the optimal models for participation in the system by its various stakeholders. </sec>

Evangelos Georgiadis, Doron Zeilberger

In 2008, Satoshi Nakamoto famously invented bitcoin, and in his (or her, or their, or its) white paper sketched an approximate formula for the probability of a successful double spending attack by a dishonest party. This was corrected by Meni Rosenfeld, who, under more realistic assumptions, gave the exact probability (missing a foundational proof); and another formula (along with foundational proof), in terms of the Incomplete Beta function, was given later by Cyril Grunspan and Ricardo Pérez-Marco, that enabled them to derive an asymptotic formula for that quantity. Using Wilf-Zeilberger algorithmic proof theory, we continue in this vein and present a recurrence equation for the above-mentioned probability of success, that enables a very fast compilation of these probabilities. We next use this recurrence to derive (in algorithmic fashion) higher-order asymptotic formulas, extending the formula of Grunspan and Pérez-Marco who did the leading term. We then study the statistical properties (expectation, variance, etc.) of the duration of a successful attack.

Muhammad Muzammal, Qiang Qu, Bulat Nasrulin, Anders Skovsgaard

A blockchain is a decentralised linked data structure that is characterised by its inherent resistance to data modification, but it is deficient in search queries, primarily due to its inferior data formatting. A distributed database is also a decentralised data structure which features quick query processing and well-designed data formatting but suffers from data reliability. In this demonstration, we showcase a blockchain database application platform developed by integrating the blockchain with the database, i.e. we demonstrate a system that has the decentralised, distributed and audibility features of the blockchain and quick query processing and well-designed data structure of the distributed databases. The system features a tamper-resistant, consistent and cost-effective multi-active database and an effective and reliable data-level disaster recovery backup. The system is demonstrated in practice as a multi-active database along with the data-level disaster recovery backup feature.

Yecheng Yao, Jungho Yi, Shengjun Zhai, Yu‐Wen Lin · 7 authors

The decentralization of cryptocurrencies has greatly reduced the level of central control over them, impacting international relations and trade. Further, wide fluctuations in cryptocurrency price indicate an urgent need for an accurate way to forecast this price. This paper proposes a novel method to predict cryptocurrency price by considering various factors such as market cap, volume, circulating supply, and maximum supply based on deep learning techniques such as the recurrent neural network (RNN) and the long short-term memory (LSTM),which are effective learning models for training data, with the LSTM being better at recognizing longer-term associations. The proposed approach is implemented in Python and validated for benchmark datasets. The results verify the applicability of the proposed approach for the accurate prediction of cryptocurrency price.

Gilary Dayan Pérez Silva

Cryptocurrencies have slowly managed to take their place in the panorama of global economic transfers, thanks to the advantages offered by traditional financial systems. By focusing on Bitcoin we can see that this cryptocurrency is global, without political, economic or social barriers. since it is based on a "person to person" system, allowing the exchange of value through the Internet without the need for a central institution or human interaction for its operation, it also has almost imperceptible transaction costs, depends on the internal movements of the platform of supply and demand, then seen in this way Bitcoin could change the current way of doing business in the world.

Paul Rimba, An Binh Tran, Ingo Weber, Mark Staples · 6 authors

No abstract is available for this record.

Tetsuya Takaishi, Takanori Adachi

No abstract is available for this record.