Blockchain Papers

Hans Schaffers

No abstract is available for this record.

Adam J. Sulkowski

No abstract is available for this record.

Thibault Schrepel

No abstract is available for this record.

Maria Michailidis

Blockchain, artificial intelligence (AI) and other technological innovations are affecting all aspects of our societies and causing some profound changes in human resource (HR) practices in business and non-profit organizations. Critical to these high tech advances is how they will affect employment patterns and the way companies will hire their workforce, influencing HR practices and the way they will manage their employees. This paper, after a short introduction, consists of three parts. The first discusses how blockchain and AI are affecting HR practices. The second looks at hiring practices at firms, while the third discusses employment patterns in the emerging age of high-tech super-automation. There is also a concluding section, discussing the implications of the forthcoming AI on employment (or unemployment) and the inevitable income inequality that is bound to develop and affect our societies.

Jasmine Chang, Michael N. Katehakis, Benjamin Melamed, Jim Shi

No abstract is available for this record.

Chao Lin, Debiao He, Xinyi Huang, Muhammad Khurram Khan · 5 authors

Blockchain can potentially be deployed in a wide range of applications due to its capability to ensure decentralization, transparency, and immutability. In this paper, we design a cryptographic membership authentication scheme (i.e., authenticating graph data) to support blockchain-based identity management systems (BIMS). Such a system is designed to bind a digital identity object to its real-world entity. Specifically, we introduce a new transitively closed undirected graph authentication (TCUGA) scheme, which only needs to use node signatures (e.g., certificates for identifying nodes). The trapdoor hash function used in our scheme allows the signer to efficiently update the certificates without the need to re-sign the nodes. In other words, our scheme is efficient even though the graph dynamically adds or deletes vertices and edges. Moreover, our proposal can efficiently provide a proof when the edge between two vertices does not exist, thus solving the existing intractability issue in transitive signature (the main tool for authenticating graph data). Finally, we prove the security of our proposed TCUGA in the standard model and evaluate its performance to show its feasibility for BIMS.

Michel Avital

The scientific enterprise relies on a peer-review process to maintain the quality of academic discourse and to ensure researchers develop a valid and consistent cumulative body of knowledge. In recent years, it appears that the review capacity in the IS field has decreased, which indicates that the community’s hunger for publication accompanies only a modest appetite for providing the necessary support to sustain the consequent increase in peer-review load. The advent of blockchain technologies and the proliferation of cryptocurrencies presents an opportunity to develop a token-based peer-review payment system that can clear the congested review pipelines while also controlling for quality and spreading the equity that peer review generates in a fair fashion through market-regulation mechanisms. Despite the digital transformation of the publishing industry, little has been done thus far to address the chronic inefficiency of the review process. The typical review cycles, which are measured in years, suggest that something needs to change. Developing a token-based peer-review payment system may be an opportunity not only to address the apparent challenge in the peer-review process but also to assert our proclaimed role as stewards of the digital revolution.

Dominique A. Tobbell

Reviewed by: Therapeutic Revolutions: Pharmaceuticals and Social Change in the Twentieth Century ed. by Jeremy A. Greene, Flurin Condrau, Elizabeth Siegel Watkins Dominique Tobbell Jeremy A. Greene, Flurin Condrau, and Elizabeth Siegel Watkins, eds. Therapeutic Revolutions: Pharmaceuticals and Social Change in the Twentieth Century. Chicago: University of Chicago Press, 2016. 320 pp. $110.00 (978-0-226-39073-4). “The practice of medicine in 1980 looked quite a bit different than it had in 1930,” write Jeremy Greene, Elizabeth Watkins, and Flurin Condrau, in the introduction to Therapeutic Revolutions (p. 8). A major component of the transformation of medicine in these decades was the massive expansion of pharmaceutical research and development that led to the introduction of scores of new prescription drugs, including antibiotics, corticosteroids, minor and major tranquilizers, oral contraceptives, and the first drugs to treat hypertension. This period of transformation has been termed by physicians, the pharmaceutical industry, policy makers, patients, and some medical historians alike as a therapeutic revolution. But as [End Page 224] Charles Rosenberg noted forty years ago in his seminal essay, “The Therapeutic Revolution,” claims of therapeutic efficacy—and thus the basis of therapeutic revolution—are both historically contingent and locally specific.1 This impressive collection of essays by leading scholars in the history and anthropology of pharmaceuticals builds on Rosenberg’s earlier analysis to problematize the concept of a twentieth-century pharmacotherapeutic revolution. By examining the intersections of pharmaceutical innovation and social transformation in North America, Western Europe, and Africa, the essays underscore the historical contingency and geographic specificity of any such revolution, and reveal what was at stake politically, economically, and culturally for the various historical actors that have mobilized the language of therapeutic revolution. The volume can be broken into four sections. The first section, with chapters by Scott Podolsky and Anne Kveim Lie, Elizabeth Watkins, and Nicolas Henckes, considers three classes of drugs held as emblematic of the mid-twentieth-century therapeutic revolution—antibiotics, oral contraceptives, and antipsychotics, respectively—and examines the degree to which these drugs were revolutionary and the political, economic, and social gains made by those who mobilized the rhetoric of revolution. The second section interrogates the measures by which pharmaceuticals introduced in the mid-twentieth century were considered revolutionary: pharmaceutical consumption and statistical measurements of therapeutic efficacy. Using pharmaceutical sales data from IMS Health, Nils Kessel and Christian Bonah show that it was older drug products like analgesics, hypnotics, and sedatives, rather than “revolutionary medicines” like antibiotics and cardiovascular drugs, that dominated the West German pharmaceutical market in the 1960s and 1970s. In their history and ethnography of tuberculosis treatment, Janina Kehr and Flurin Condrau show the ways in which clinical trials data documenting the efficacy of streptomycin to treat tuberculosis in the 1950s was mobilized as “proof of the universal effectiveness of antibiotics regardless of social situation,” even as antibiotic resistance undermined treatment efforts and tuberculosis persisted as a global health concern (p. 135). This “statistical modeling of success” (p. 135), Kehr and Condrau argue, “transformed tuberculosis from a subject of cutting-edge biomedical research into a disease that physicians considered ‘boring’ . . . until it reemerged in the late twentieth century as multidrug resistant tuberculosis and extremely drug-resistant tuberculosis, and thus a subject of renewed biomedical excitement” (p. 12). The third section shifts focus from the United States and Western Europe to the Global South and examines the intersections of pharmaceutical innovation, international development, and global public health, highlighting the spatial-temporal character and political economy of the therapeutic revolution. Jeremy Greene analyzes the ways in which American lawmakers, physicians, patients, regulators, and pharmaceutical companies mobilized arguments about the [End Page 225] cause of and potential solutions to geographic disparities in pharmaceutical access during the 1960s and 1970s in an attempt to shape both domestic health policy and international development agendas. Paul Farmer, Matthew Basilico, and Luke Messac revisit the debate, ignited by Thomas McKeown in the 1960s, over the role of medicine in public health. Their analysis of recent economic, ethnographic, and epidemiological data makes clear that despite the persistent problem of uneven access, pharmaceuticals have contributed to a significant population-level mortality decline in the Global South. Julie Livingston’s history and ethnography...

Felix Heieck, Tatiana Ermakova, Benjamin Fabian, Stefan Lessmann

No abstract is available for this record.

Armando Nova González, Galia Figueroa Alfonso

The Cuban government has implemented a series of agricultural transformations since 2007 to increase the country’s agricultural self-sufficiency and reduce its dependence on food imports. These include the transfer in usufruct, i.e. use rights only, of State-owned land to non-State producers (i.e. cooperatives and private farmers), moderate price reforms, the decentralization of decision making, and the gradual relaxation of existing forms of agricultural commercialization. As a result of these measures, the area planted, as well as physical output and agricultural yields (in selected non-sugar crop categories) have shown mixed results, and still remain below desired levels. There are three fundamental unresolved issues that have prevented Cuba’s agricultural sector from achieving desired levels: (1) the need to achieve the “realization of property”; (2) recognition and acceptance of the market as a complementary economy in coordination with a planning mechanism; and (3) absence of a systemic focus to achieve the successful completion of the agricultural production cycle (i.e. the value chain). These unresolved issues should be addressed through: (1) consolidating markets for inputs, where producers can obtain essential inputs at prices that correspond to the prices they can obtain for their output; (2) granting greater autonomy to agricultural producers to allow them to decide when, where, and to whom they can sell their output, after social contracts have been fulfilled; (3) diversifying types of agricultural commercialization to permit greater participation by non-State economic actors; (4) allowing agricultural producers to freely hire the labor necessary to sustain and increase production; and (5) providing agricultural producers with needed financing and technical assistance. Please refer to Supplementary Materials, Full text Spanish version of this article, for a full text Spanish version of this article.

Chengrong Chen

Although the smart contract as the new product in the era of block chain contract shall not be only limited to the property-related agreements stipulated by the Contract Law of People's Republic of China, the Chinese contract provisions shall be perfected accordingly due to its contract attribute. In order to promote the formation and validity of the smart contract, the full capacity requirements for civil conduct of the parties to the property-related contract as well as the formulation of "Withdrawal Provisions" and the connotation of social public interests shall attract legislators' attention. But in view of two major features of smart contract, on the one hand, the legislators shall consider distinguishing the remedies of continuous contract and instant contract; on the other hand, the legislators shall perfect the remedy system for the "Alteration" of smart contracts in the process of waiting for verification.

Dimitrios Linardatos

No abstract is available for this record.

Anatoly Yakovlevich Zaporozhan

The article is devoted to the causes of the origin, the consequences of the functioning of the crypto currency and the prospect of restructuring the modern financial system on the basis of blocking technology. The article shows that the crypto currency emerged as an evolutionary stage in the development of the world payment system, that the modern financial system is developing in a dead-end direction, that the use of crypto currency and its derivatives in practice can destroy the world payment system and world financial market from within. It is suggested that, based on the technology of the block, a modern financial system can be restructured.

Оxana Ananova

The article is devoted to new directions of development of the digital economy. The analysis of technology development and cryptocurrency blokcheyn. Analyzed the problems and prospects of transition to digital economy technology.

Aleksandr Berdyshev

The history of creating bitcoin cryptocurrencies has been considered, the main features of cryptocurrencies and cryptocurrency market have been identified. Based on the identification of features of the blockchain technology, the possibilities of making settlements outside the traditional financial system have been determined. Special attention has been paid to the issue of legal regulation of cryptocurrency in various countries. According to the results of a study of current trends in the cryptocurrency market, in the conditions of a significant decline in the market value of bitcoin in 2018, as the flagship of the cryptocurrency market, prospects for its development have been determined

Melanie L. Fein

No abstract is available for this record.

Julia Reynolds, Leopold SSgner, Martin Wagner, Dominik Wied

This paper applies recently developed procedures to monitor and date so-called "financial marketdislocations", defined as periods in which substantial deviations from arbitrage parities take place. In particular, we focus on deviations from the triangular arbitrage parity for exchange rate triplets from a cointegration perspective. Due to increasing attention on and importance of mispricing in the market for cryptocurrencies, we include the cryptocurrency Bitcoin in addition to fiat currencies. We do not find evidence for substantial deviations from the triangular arbitrage parity when only traditional fiat currencies are concerned, but document significant deviations from triangular arbitrage parities in the newer markets for Bitcoin. We confirm the importance of our results for portfolio strategies by showing that a currency portfolio that trades based on our detected break-points outperforms a simple buy-and-hold strategy.

М. А. Магомедов, A.M. Alikberova

No abstract is available for this record.

Yanfeng Wang, Feng Li, Jinya Hu, Dong Zhuang

This paper addresses recognizing fraud users on a Bitcoin exchange website-bitcoin-otc. According to online rating records provided by the website, some users behave significantly different from others. Seeing that, the classical K-means clustering algorithm is proposed to identify these abnormal users. K-means algorithm is an unsupervised clustering algorithm that clusters users based on feature similarity. Therefore, performance of K-means algorithm relies on the features. This paper explored and found the best collection of features based on real record data, e.g., mean of total ratings sent. Since the selected features are not observed for record set, the website should offer these features for potential traders.

Enrico Tedeschi, Håvard D. Johansen, Dag Johansen

This thesis describes a longitudinal study of Bitcoin,\nthe perhaps most popular blockchain based system today.\nPublic blockchains have emerged as a plausible messaging substrate\nfor applications that require highly reliable communication.\nHowever, sending messages over existing blockchains can be cumbersome\nand costly as miners require payment to establish consensus on the\nsequence of messages, since the electricity consumption\nneeded to run miners is not negligible.\nThe blockchain protocol requires an always\ngrowing size of the information stored in it so its scalability is\nthe biggest problem. For that reason we decided to\ncollect and store data locally in our own data structure,\nnecessary for the analysis,\nallowing us to save up to 10 times the amount of disk space.\nToday, systems using the blockchain protocol are emerging,\nand cryptocurrencies are a glaring example\nof its implementation. Bitcoin\nrepresents the largest cryptocurrency on market,\nand it has to face a massive scale due to its popularity,\nhaving in 2012 about fifty thousands\ntransaction per day and reaching now,\nin 2017, more than three hundred fifty\nthousands of transactions\napproved every day.\n\nThis massive scale in the system leads to a saturation\nof the messaging substrate, hence performance issues.\nIn this thesis we will focus also on the Bitcoin network\nperformance, in particular, transaction throughput and\nlatency.\nFrom 2009 to 2017 a lot of analyses on\nthe blockchain have been performed,\nenhancing the considerable change in\nthe block size limit,\nfrom 256 bytes to 1MB,\nas an attempt to overcome scalability problems.\nDifferent papers were published, discussing\nwhether changing or not the block size limit.\nIn addition, the Bitcoin price increased\nfrom ~0.7$ to more than 7.000$,\nmaking the system even more desirable for\nminers, but causing several complications\nin the fee and reward mechanism.\nWe evaluate and discuss possible ways to improve this fee\nmechanism in order to guarantee more revenue for miners along\nwith an user fee optimization.\n\nWe finally present our own system for\nlongitudinal analysis on the Bitcoin blockchain,\nBAS. It generates a dataset\nwhich contains a significant portion of\nthe whole blockchain, updated on September 2017.\nWe discuss our results and compare them with\nother evaluations from past years, considering\nthree main key points: scalability,\nperformance and fees/costs.\nWe discuss how scalability affects performance,\nand how the costs and fees are dependent\nfrom them both.\nWe want also to take into consideration\nthe environmental impact of Bitcoin\nand how it affects the coming\nof new cryptocurrencies.\nWe evaluate and\npropose, using machine learning techniques,\ntwo different cost prediction models that aim to\npredict bandwidth for upcoming transactions\naccording the fee they are willing to pay, and\nthe expected revenue for miners according to\nthe time spent mining.\nThese models can\nbe used by application to throttle network traffic to optimize\nmessage delivery. We also discuss\nwhether the block size limit should be increased for a higher\nthroughput or not.

Hans-Peter Deutsch

No abstract is available for this record.

Muhammad Arifin Nasution, Rudy Salam Sinaga

The decentralized system of the Indonesian government to give jobs to the region to carry out development in the area in response to the various regional development policy. Offend public policy perspective the role of government and stakeholders. The focus of the stakeholders in this research is student organizations. This study aims to investigate the model student political movement in advocating for policies in the autonomous region in the province of North Sumatera. The method of investigation used to answer research questions using a mixed methods design sequential exploratory through collaboration grounded theory approach and surveys. Data gathering using depth interview and survey techniques used to test the hypothesis that emerged from the research results at the earliest. The study population is groups of student movement organizations in the province of North Sumatra with a set of samples of the four groups of organizations active student movement at the University of Sumatera Utara. The findings of this study describe a group of student movement organizations in conducting policy advocacy stages tend stalled at the stage of political socialization in advocating policies and limitations in order to maximize the level of policy advocacy in the parliament lobby.

Yupeng Zhang

We study the problem of argument systems, where a computationally weak verifier outsources the execution of a computation to a powerful but untrusted prover, while being able to validate that the result was computed correctly through a proof generated by the prover. In addition, the zero-knowledge property guarantees that proof leaks no information about the potential secret input from the prover. Existing efficient zero-knowledge arguments with sublinear verification time require an expensive preprocessing phase that depends on a particular computation, and incur big overhead on the prover time and prover memory consumption. This thesis proposes new constructions for zero-knowledge arguments that overcome the above problems. The new constructions require only a one time preprocessing and can be used to validate any computations later. They also reduce the overhead on the prover time and memory by orders of magnitude. We apply our new constructions to build a verifiable database system and verifiable RAM programs, leading to significant improvements over prior work.

Franca-Alexandra Rupprecht

Collaboration aims to increase the efficiency of problem solving and decision making by bringing diverse areas of expertise together, i.e., teams of experts from various disciplines, all necessary to come up with acceptable concepts. This dissertation is concerned with the design of highly efficient computer-supported collaborative work involving active participation of user groups with diverse expertise. Three main contributions can be highlighted: (1) the definition and design of a framework facilitating collaborative decision making; (2) the deployment and evaluation of more natural and intuitive interaction and visualization techniques in order to support multiple decision makers in virtual reality environments; and (3) the integration of novel techniques into a single proof-of-concept system. Decision making processes are time-consuming, typically involving several iterations of different options before a generally acceptable solution is obtained. Although, collaboration is an often-applied method, the execution of collaborative sessions is often inefficient, does not involve all participants, and decisions are often finalized with- out the agreement of all participants. An increasing number of computer-supported cooperative work systems (CSCW) facilitate collaborative work by providing shared viewpoints and tools to solve joint tasks. However, most of these software systems are designed from a feature-oriented perspective, rather than a human-centered perspective and without the consideration of user groups with diverse experience and joint goals instead of joint tasks. The aim of this dissertation is to bring insights to the following research question: How can computer-supported cooperative work be designed to be more efficient? This question opens up more specific questions like: How can collaborative work be designed to be more efficient? How can all participants be involved in the collaboration process? And how can interaction interfaces that support collaborative work be designed to be more efficient? As such, this dissertation makes contributions in: 1. Definition and design of a framework facilitating decision making and collaborative work. Based on examinations of collaborative work and decision making processes requirements of a collaboration framework are assorted and formulated. Following, an approach to define and rate software/frameworks is introduced. This approach is used to translate the assorted requirements into a software’s architecture design. Next, an approach to evaluate alternatives based on Multi Criteria Decision Making (MCDM) and Multi Attribute Utility Theory (MAUT) is presented. Two case studies demonstrate the usability of this approach for (1) benchmarking between systems and evaluates the value of the desired collaboration framework, and (2) ranking a set of alternatives resulting from a decision-making process incorporating the points of view of multiple stake- holders. 2. Deployment and evaluation of natural and intuitive interaction and visualization techniques in order to support multiple diverse decision makers. A user taxonomy of industrial corporations serves to create a petri network of users in order to identify dependencies and information flows between each other. An explicit characterization and design of task models was developed to define interfaces and further components of the collaboration framework. In order to involve and support user groups with diverse experiences, smart de- vices and virtual reality are used within the presented collaboration framework. Natural and intuitive interaction techniques as well as advanced visualizations of user centered views of the collaboratively processed data are developed in order to support and increase the efficiency of decision making processes. The smartwatch as one of the latest technologies of smart devices, offers new possibilities of interaction techniques. A multi-modal interaction interface is provided, realized with smartwatch and smartphone in full immersive environments, including touch-input, in-air gestures, and speech. 3. Integration of novel techniques into a single proof-of-concept system. Finally, all findings and designed components are combined into the new collaboration framework called IN2CO, for distributed or co-located participants to efficiently collaborate using diverse mobile devices. In a prototypical implementation, all described components are integrated and evaluated. Examples where next-generation network-enabled collaborative environments, connected by visual and mobile interaction devices, can have significant impact are: design and simulation of automobiles and aircrafts; urban planning and simulation of urban infrastructure; or the design of complex and large buildings, including efficiency- and cost-optimized manufacturing buildings as task in factory planning. To demonstrate the functionality and usability of the framework, case studies referring to factory planning are demonstrated. Considering that factory planning is a process that involves the interaction of multiple aspects as well as the participation of experts from different domains (i.e., mechanical engineering, electrical engineering, computer engineering, ergonomics, material science, and even more), this application is suitable to demonstrate the utilization and usability of the collaboration framework. The various software modules and the integrated system resulting from the research will all be subjected to evaluations. Thus, collaborative decision making for co-located and distributed participants is enhanced by the use of natural and intuitive multi-modal interaction interfaces and techniques.