Blockchain Papers

Garrick Hileman, Michel Rauchs

No abstract is available for this record.

Jun Wang, Peng Wu, Xiangyu Wang, Wenchi Shou

Current construction engineering management suffers numerous challenges in terms of the trust, information sharing, and process automation. Blockchain which is a decentralised transaction and data management technology, has attracted increasing interests from both academic and industrial aspects since 2008. However, most of the existing research and practices are focused on the blockchain itself (i.e. technical challenges and limitations) or its applications in the finance service sector (i.e. Bitcoin). This paper aims to investigate the potential of applying blockchain technology in the construction sector. Three types of blockchain-enabled applications are proposed to improve the current processes of contract management, supply chain management, and equipment leasing, respectively. Challenges of blockchain implementation are also discussed in this paper.

Damiano Di Francesco Maesa, Paolo Mori, Laura Ricci

No abstract is available for this record.

Žiga Turk, Robert Klinc

Blockchain technology enables distributed, encrypted and secure logging of digital transactions. It is the underlying technology of Bitcoin and other cryptocurrencies. Blockchain is expected to revolutionize computing in several areas, particularly where centralization was unnatural and privacy was important. In the paper, we present research on where and how this technology could be useful in the construction industry. The work is based on the study of literature on open issues that exist in construction process management. These are than matched to the capabilities of blockchain. We are motivated by the fact that construction projects involve a dynamic grouping of several companies. We study the degree to which the relationships among them are hierarchical or peer-to-peer and note that particularly in information intensive phases, centralization of information management was necessary because of technology. When using un-constraining technology, communication patterns among participants show a peer-to-peer nature of the relationships. In such environment, blockchain can provide a trustworthy infrastructure for information management during all building life-cycle stages. Even if building information modelling (BIM) is used, which assumes a centralized building information model, there is a role for blockchain to manage information on who did what and when and thus provide a basis for any legal arguments that might occur. On the construction site blockchain can improve the reliability and trustworthiness of construction logbooks, works performed and material quantities recorded. In the facility maintenance phase, blockchain's main potential is the secure storage of sensor data which are sensitive to privacy. We conclude that blockchain provides solutions to many current problems in construction information management. However, it is more likely that it will be built into generic IT infrastructure on top of which construction applications are built, rather than used directly by authors of construction related software. It has a potential to make construction processes less centralized which opens needs for research in that direction.

Tomaso Aste, Paolo Tasca, Tiziana Di Matteo

The authors describe blockchain's fundamental concepts, provide perspectives on its challenges and opportunities, and trace its origins from the Bitcoin digital cash system to recent applications.

Qi Xia, Emmanuel Boateng Sifah, Kwame Omono Asamoah, Jianbin Gao · 6 authors

The dissemination of patients' medical records results in diverse risks to patients' privacy as malicious activities on these records cause severe damage to the reputation, finances, and so on of all parties related directly or indirectly to the data. Current methods to effectively manage and protect medical records have been proved to be insufficient. In this paper, we propose MeDShare, a system that addresses the issue of medical data sharing among medical big data custodians in a trust-less environment. The system is blockchain-based and provides data provenance, auditing, and control for shared medical data in cloud repositories among big data entities. MeDShare monitors entities that access data for malicious use from a data custodian system. In MeDShare, data transitions and sharing from one entity to the other, along with all actions performed on the MeDShare system, are recorded in a tamper-proof manner. The design employs smart contracts and an access control mechanism to effectively track the behavior of the data and revoke access to offending entities on detection of violation of permissions on data. The performance of MeDShare is comparable to current cutting edge solutions to data sharing among cloud service providers. By implementing MeDShare, cloud service providers and other data guardians will be able to achieve data provenance and auditing while sharing medical data with entities such as research and medical institutions with minimal risk to data privacy.

Kari Korpela, Jukka Hallikas, Tomi Dahlberg

Digital supply chain integration is becoming \ increasingly dynamic. Access to customer demand \ needs to be shared effectively, and product and service \ deliveries must be tracked to provide visibility in the \ supply chain. Business process integration is based on \ standards and reference architectures, which should \ offer end-to-end integration of product data. \ Companies operating in supply chains establish \ process and data integration through the specialized \ intermediate companies, whose role is to establish \ interoperability by mapping and integrating companyspecific \ data for various organizations and systems. \ This has typically caused high integration costs, and \ diffusion is slow. This paper investigates the \ requirements and functionalities of supply chain \ integration. Cloud integration can be expected to offer \ a cost-effective business model for interoperable \ digital supply chains. We explain how supply chain \ integration through the blockchain technology can \ achieve disruptive transformation in digital supply \ chains and networks.

Sinclair Davidson, Primavera De Filippi, Jason Potts

Abstract Blockchains are a new digital technology that combines peer-to-peer network computing and cryptography to create an immutable decentralised public ledger. Where the ledger records money, a blockchain is a cryptocurrency, such as Bitcoin; but ledger entries can record any data structure, including property titles, identity and certification, contracts, and so on. We argue that the economics of blockchains extend beyond analysis of a new general purpose technology and its disruptive Schumpeterian consequences to the broader idea that blockchains are an institutional technology. We consider several examples of blockchain-based economic coordination and governance. We claim that blockchains are an instance of institutional evolution.

Zhetao Li, Jiawen Kang, Rong Yu, Dongdong Ye · 6 authors

In industrial Internet of things (IIoT), peer-to-peer (P2P) energy trading ubiquitously takes place in various scenarios, e.g., microgrids, energy harvesting networks, and vehicle-to-grid networks. However, there are common security and privacy challenges caused by untrusted and nontransparent energy markets in these scenarios. To address the security challenges, we exploit the consortium blockchain technology to propose a secure energy trading system named energy blockchain. This energy blockchain can be widely used in general scenarios of P2P energy trading getting rid of a trusted intermediary. Besides, to reduce the transaction limitation resulted from transaction confirmation delays on the energy blockchain, we propose a credit-based payment scheme to support fast and frequent energy trading. An optimal pricing strategy using Stackelberg game for credit-based loans is also proposed. Security analysis and numerical results based on a real dataset illustrate that the proposed energy blockchain and credit-based payment scheme are secure and efficient in IIoT.

Nir Kshetri

This column evaluates blockchain's roles in strengthening security in the Internet of Things (IoT). Key underlying mechanisms related to the blockchain-IoT security nexus are covered. From a security standpoint, the article highlights how blockchain-based solutions could be, in many aspects, superior to the current IoT ecosystem, which relies mainly on centralized cloud servers. Using practical applications and real-world examples, the article argues that blockchain's decentralized nature is likely to result in a low susceptibility to manipulation and forgery by malicious participants. Special consideration is given to how blockchain-based identity and access management systems can address some of the key challenges associated with IoT security. The column provides a detailed analysis and description of blockchain's roles in tracking the sources of insecurity in supply chains related to IoT devices. Using blockchain, it is also possible to contain an IoT security breach in a targeted way after it is discovered. The column also discusses and evaluates initiatives of organizations, interorganizational networks, and industries on the frontlines of blockchain.

Lin William Cong, Zhiguo He, Jingtao Zheng

Blockchain technology provides decentralized consensus and potentially enlarges the contracting space through smart contracts. Meanwhile, generating decentralized consensus entails distributing information that necessarily alters the informational environment. We analyze how decentralization relates to consensus quality and how the quintessential features of blockchain remold the landscape of competition. Smart contracts can mitigate informational asymmetry and improve welfare and consumer surplus through enhanced entry and competition, yet distributing information during consensus generation may encourage greater collusion. In general, blockchains sustain market equilibria with a wider range of economic outcomes. We further discuss the implications for antitrust policies targeted at blockchain applications. Received May 31, 2017; editorial decision May 29, 2018 by Editor Itay Goldstein.

Majid Amjad Hussain, Sadia Khalil, Shahzad Saleem

With the increase in the use of virtual currencies across the globe, the security of Bitcoin wallets has become a serious concern for the Bitcoin community. The developers are trying to implement concrete security solutions in Bitcoin wallets to ensure that no vulnerability gets exploited. However, a large number of known, as well as zero-day attacks, are launched on the Bitcoin wallets on a daily basis, resulting in a loss of bitcoins. In this regard, this paper presents a security analysis of existing Android wallets. We demonstrate how the implemented security practices can be bypassed by malicious entities, causing financial loss to Bitcoin users. As a countermeasure, we present a smart card based authentication scheme which will protect the users from all of the identified attacks.

Julius Tamawiwy, Jullie J. Sondakh, Jessy D.L Warongan

The main objective of regional autonomy is to improve public services and promote the local economy in Indonesia. Capital expenditures for public services is used to finance expenditure in investing activities (add assets) aimed at improving public infrastructure that results can be used directly by the public. Developed regions tend to maintain the structure of expenditure into maintenance expenditure. The shift in spending patterns in the local government often triggered concerns about the extent to which the amount of local revenue affects the pattern of local government spending, especially capital expenditure for public services. This study purposes to analyze growth of revenue (PAD), the ​​fiscal decentralization, financial effectiveness and efficiency of the Local Government Financial Management to the capital expenditure for public services. The method used is quantitative method with a sampling technique using judgment sampling which took samples with consideration of the availability of data in the Local Government Financial Statements Reports in the Province of North Sulawesi by 10 districts/cities of Local Government in North Sulawesi since 2010 to 2015. The analytical method used is a multiple regression using SPSS 20 application assistance. The results show that PAD growth is effect as positive and significant capital expenditures for public services, fiscal decentralization is negative effect and not significant toward capital expenditures for public services, effectiveness and efficiency of local financial is effect as positive but not significant toward capital expenditures for public services..

Koteswara Rao Ballamudi

Distributed ledger technology (DLT) that stores data (usually immutable and sequenced transaction records) in a decentralized way through cryptography and consensus algorithms. The first widely recognized implementation of the blockchain took place in 2009 on the Bitcoin public blockchain. Since then, other types of blockchain have been developed for a wide range of applications and features built on common principles such as decentralization, encryption, consensus, and immutability. In particular, blockchain technology is most widely used in transaction settlement and digital currency banks and the financial sector, as well as in supply chain applications that help participants solve problems quickly and efficiently. Other use cases continue to be developed. As a form of information management, blockchain and related DLTs offer advantages over traditional databases and may help develop certain new technologies such as the Internet of Things. Blockchain regulation is currently restricted at the international and federal levels, but state-level legislation provides support and awareness of aspects of blockchain technology. Most of the current regulations are in the form of self-regulation by blockchain developers and related communities, but many challenges and risks such as data privacy and security need to be addressed in the near future.

Sai Srujan Gutlapalli

Blockchains are distributed ledgers. Distributed ledgers replace centralized ledgers. Distributed ledgers use nodes—computers—to record, share, and synchronize transactions in their electronic ledgers. The paper examines how blockchain data is arranged into blocks and how an append-only mode chain links them. Distributed ledger technology (DLT) encrypts and consensuses immutable and sequential transaction records. Bitcoin pioneered blockchain. Since then, many blockchains with decentralization, encryption, consensus, and immutability have been developed for diverse uses. Blockchain technology is most typically used in transaction settlement, digital currency banks, and supply chain applications to solve problems quickly. The study examines how blockchain and DLTs might improve information management and build new technologies like the Internet of Things. The study shows how legal issues encourage blockchain technology despite limited international and federal restrictions. However, data privacy and security must be addressed immediately.

Ermira Korra, Eliona Gremi, Faik Gjolena

In the terms of decentralization and local autonomy, increase of financial capacity, is the result of more use of fiscal and financial instruments, as well as increasing the effectiveness work of the local government. They are facing a series of complex issues related to the functions they have to carry and their financial capacities against these needs. Local Government Units in Albania have few funds to fill the needs for financing great projects mainly infrastructure, so in this paper we aim to analyze the financing instruments of local government. Borrowing from financial institutions and second level banks is the main financial instrument for Local Government to financing their great investment for the community. This is a new financing instrument for LGUs in Albania that is considered as a strong financial lever to enable the financing of their budgets and great projects capital investment. Another instrument are guidelines constructed in similar models and experiences of countries in political and economic tradition with that of Albania, the issue of bonds of LG / municipal bonds which are regulated by laws. Programs of international agencies to support lending to the local government is also another a significant financing instrument for LGUs in Albania to fulfilled their needs. DOI: 10.5901/ajis.2016.v5n3s1p387

Pratyush Dikshit, Kunwar Singh

Bitcoin was introduced in a self-published paper by Satoshi Nakamoto in October, 2008[1, 2]. Bitcoin is a decentralized system which requires no central authority. In recent years, bitcoin has become increasingly accepted and used in many fields in place of physical cash. Bitcoin is a peer-to-peer network of nodes that distribute and record transactions [3]. Bitcoin transaction is a statement that Player 1 (address 1) would like to transfer some bitcoin values to Player 2 (address 2), signed by Player 1 by his private key. Transactions are verified by network nodes and confirmed in a public distributed ledger called the block chain. The block chain consists of a series of blocks in which each block contains the hashed value of subsequent block. Every bitcoin block contains a set of verified transactions that are collected from the bitcoin broadcast network. It is assumed that the majority of nodes in the bitcoin network are honest. This makes the verification done by the nodes is correct with high probability. More technically, bitcoin is an electronic-cash system based on cryptographic algorithms.

Christopher Natoli, Vincent Gramoli

In this paper, we identify a new form of attack, called the Balance attack, against proof-of-work blockchain systems. The novelty of this attack consists of delaying network communications between multiple subgroups of nodes with balanced mining power. Our theoretical analysis captures the precise tradeoff between the network delay and the mining power of the attacker needed to double spend in Ethereum with high probability. We quantify our probabilistic analysis with statistics taken from the R3 consortium, and show that a single machine needs 20 minutes to attack the consortium. Finally, we run an Ethereum private chain in a distributed system with similar settings as R3 to demonstrate the feasibility of the approach, and discuss the application of the Balance attack to Bitcoin. Our results clearly confirm that main proof-of-work blockchain protocols can be badly suited for consortium blockchains.

Shilpa Sindhu, Sahil Khatkar, Anupama Panghal

Objectives: This study is aimed at analyzing various facets of Fiscal Federalism and its impact on the growth of states in India. Methods/Analysis: The Study proposes a model to test the impact of autonomy and hard budget constraints, two important features of decentralization, on the economies of the states. The model has been analyzed using the Fixed Effects Least Squares method for panel data using EViews. Findings: The results point out quite a few aspects of the impact of fiscal federalism on Indian states. The paper concludes by giving possible reasons for the negative relation between autonomy with growth and the positive relation between central grants with growth. The fact that the OwnTax ratio is negatively related to the GSDP growth rate shows that the level of autonomy of a state is negatively related to the growth of the state. The study also revealed a high dependence of the states on the grants and tax sharing mechanisms for growth. It was found that the central intervention in the states’ economy was positively related to their growth, which points to soft budget constraints on the states which depend highly on the central government to finance their spending. The overall level of decentralization was also found to be quite poor, though the relationship is not very economically significant. Applications/Improvement: The Study highlights that trade-off between the autonomy and budget constraint aspects of fiscal federalism needs to be a major concern and work area for policy makers in India.Keywords: Economic Growth, Fiscal Federalism, Tax

Beata Szetela, Grzegorz Mentel, Stanisław Gędek

In this research we have tried to identify the relationship between the exchange rate for bitcoin to the leading currencies such as Dollar, Euro, British Pound and Chinese Yuan and Polish zloty as well. We have applied ARMA and GARCH models to model and to analyze the conditional mean and variance. The appliance of GARCH models have identified some dependency in explanation conditional variance between bitcoin and US Dollar, Euro and Yuan, while ARMA analysis have shown no relations between bitcoin and other dependent variables.

Lan Huong Nguyen

Vietnam is among the most climate change vulnerable and disaster-prone nations, and water is the first sector to be affected by climate change.Being one of the developing countries launching climate policies, the country has recently announced to strive for a low-carbon economy.Nevertheless, there is a mismatch in the development strategy for the power sector and the climate-related policies which might lead to the ambiguous in the further implementation of climate change mitigation strategies.To achieve sustainable development and green growth, the government goal is to increase renewable energy share to 9.4 % and wastewater treatment to 80 % in the year 2030.However, there are no specific guidelines to accomplish the multiple targets.The research goal is to propose the integrated mechanism of renewable energy supply (run-off-river hydropower) and decentralized wastewater treatment system.The proposed mechanism is expected to reduce greenhouse gas emission from power generation and alleviate environment pollution from domestic wastewater.The objective of this study has been three-fold.First, to estimate the potential of small hydropower (in the form of run-off-river hydropower) and its contribution to greenhouse gas emission reductions in the representative river basin of Vietnam.Second, to estimate the potential for greenhouse gas emission reductions by providing adequate domestic wastewater treatment facilities.Third, to demonstrate the co-benefits of the integrated mechanism through scenario analysis, considering social, financial feasibility and carbon crediting scheme.The result of our study highlighted that run-off-river hydropower potential has potential to fulfill the electricity demand for the rural villages in the Vu Gia-Thu Bon River basin, especially remote communities without access to the grid with the total capacity 277 MW with a capacity factor of 40.2 %.Also, off grid hydropower can serve as alternative electricity source to ensure the reliability of the grid by reducing grid load, prevent from blackout and brownout.Besides, renewable electricity generation from ROR hydropower scheme will provide power for decentralized wastewater treatment facilities within the watersheds.This study proposes scenario four is the most applicable for the region with the GHG reduction amount of 0.45 mil.tCO2eq.In this scenario, the Japanese Johkasou system could serve 30 % of the total rural household especially in the mountainous areas in the up and middle stream of the Vu Gia-Thu Bon River basin, where the population density is relatively lower than the downstream.In populated areas downstream, centralized or semi-centralized wastewater treatment system is favored and more efficient.Full implementation of ROR hydropower generation and wastewater treatment system would reduce the total amount of 0.38 million tCO2eq per year (on-grid) and 0.60 million tCO2eq per year (off-grid).Regarding financial aspect of investment in wastewater treatment facilities, the main budget comes from external assistant Official Development Assistance (ODA) in the form of grants, technical assistance and loans; and the priority is to invest in urban wastewater treatment.Therefore, the obstacle for installation of Johkasou and wastewater treatment system in the rural and less developed area remains as one of the biggest challenges.Nevertheless, this treatment scheme, besides environmental conservation, a substantial amount of GHG emissions can be reduced.With existing Carbon trading schemes, this system has potential to attract carbon finance from Clean Development Mechanism (CDM) or Joint Crediting Mechanism (JCM) projects.Emissions reduction from wastewater treatment can be credited to existing carbon-trading scheme, to minimize the initial cost of system construction including installation of Johkasou.On the other hand, GHG emissions can also be reduced utilizing renewable energy for wastewater treatment eliminates grid emissions.The high uncertainty of emission calculation can be minimized by the accessibility of local data or existing empirical data.The research finding indicates government's GHG emissions reduction target in the waste sector can be set up to 16 %.Moreover, a method to develop emission inventory for wastewater treatment in rural areas of developing countries from the watershed approach is proposed.Also, this study raises the potential of utilizing existing carbon emission trading schemes for an initial investment of the wastewater treatment facilities through carbon credit.Also, the small hydropower system has a lower cost compared with conventional diesel generator based system, and even lower than the retail electricity tariff from the government.The economic advantage can interest private entities to invest in rural electrification even without government subsidies.Therefore, creates advantages for implementing on/off-grid hydropower than other renewable energy such as the wind or solar PV.The negative abatement cost for small hydropower over conventional diesel generator which is -195.51USD/tCO2 (off grid) or -48.18USD/ tCO2 indicates that cost for CO2 mitigation can be saved.Although this result is vary depending on the fuel price projection as well as plant capacity and discounted value of electricity sold, the similar negative value is observed from Blum et al., (2013).Finally, the demonstration of co-benefits was performed by scenario-based analysis.The result shows that under domestic conditions the project return period is 18.39 years, and IRR is 8.5 %.The IRR for base case is smaller than the benchmark IRR, which is 10% indicate that this project would likely not happen.If the project is implemented under the integrated mechanism, the project payback periods are from 7.31 years to 18.17 years and IRRs are from 10.04% to 26.57%.Our study also emphasizes the potential of ROR hydropower development for rural electrification in the context of Vu Gia-Thu Bon River basin.This study employed the holistic approach to providing private entities as well as foreign investors with a comprehensive assessment of demand, supply, and economic values.The results from this study may assist the private sector to make the decision for investment in rural electrification projects.The study provides quantitative evidences for the government of Vietnam, policy makers as well as developers.There is a potential to establish and implement an integrated mechanism for sustainable energy supply and rural development by utilizing existing emission trading schemes such as CDM co-benefits or JCM v

Xin Li, Chong Wang

No abstract is available for this record.

Luis E. Torres-Núñez

The growing economic inability in Latin-American states to finance public universities, has positioned public funding as a common theme in almost all targeted reforms of higher education. Insufficient public resources are compromising the effectiveness of academic management in public universities, without knowing the key economic issues for strengthening public sector policies. This essay is intended to: propose a new system of criteria for funding of higher education; based on the analysis of the Venezuelan experience in allocations of public resources used to finance higher education institutions during the 2000-2015 period. It is a documentary research. The proposal contains seven (7) integrating elements that would lead to the establishment of a funding policy for higher education. Finally, it is suggested that the State exceeds the old negotiated "incremental “schemes, "rigid" budget formulas and deferred funding allocations, which fail to identify basic needs and costs associated to the academic management of higher education institutions, in terms of promoting efficiency, equity and decentralization in public funding for the Venezuelan higher education system.

Banque Interaméricaine de Développement, Banco Interamericano de Desenvolvimento

This Breve is based on the original thesis work and on a webinar presented by Dr. Fábio Ferride-Barros regarding the "Ethics of Health Resources Allocation in the Publicly Financed Health Care System in Brazil." The perspective offered in this Breve complements a previously published issue documenting the use of health technology evaluation in decision-making in Brazil's health sector (IDB, 2015). The Breve introduces the challenges of priority setting in the context of a large and decentralized national universal health care system, which confronts resource scarcity and substantial inequalities.