This appendix describes the following topics: symmetric cryptography; public key cryptography; key derivation functions; hashes; nonces; and zero-knowledge proofs. Inspec keywords: public key cryptography Other keywords: nonces; symmetric cryptography; zero-knowledge proofs; cryptographic concepts; hashes; key derivation functions; public key cryptography Subjects: Cryptography; Cryptography theory
This paper looks at some issues that may arise as Bitcoin, and its underlying blockchain technology, plays a greater role in commercial transactions. Bitcoin and other public blockchains permit identification of every transaction that has occurred. But tracing bitcoin – an issue arising in cases from fraud to secured transactions - will not be technically possible in many cases. Equitable tracing doctrines, along with information beyond the blockchain, may fill the gap. Blockchain smart contracts may provide self-help as an alternative to legal enforcement. Coding transactions, however, will not necessarily put them beyond the scope of contract law. Beyond that, some smart contracts may be functionally more like letters of credit, and so be subject to the principles of documentary credits. Smart contracts used in financing transactions may be limited by the debtor-protective principles of Article 9 of the Uniform Commercial Code. Existing commercial law principles could be adapted to cryptocurrencies and the blockchain, as some have persuasively argued. Sensitivity to existing practices should guide such regulation, as discussion of relevant adaptations of the law to technological change suggest.
Rakshit Agrawal, Luca de Alfaro, Vassilis Polychronopoulos
Many prediction problems can be phrased as inferences over local neighborhoods of graphs. The graph represents the interaction between entities, and the neighborhood of each entity contains information that allows the inferences or predictions. We present an approach for applying machine learning directly to such graph neighborhoods, yielding predicitons for graph nodes on the basis of the structure of their local neighborhood and the features of the nodes in it. Our approach allows predictions to be learned directly from examples, bypassing the step of creating and tuning an inference model or summarizing the neighborhoods via a fixed set of hand-crafted features. The approach is based on a multi-level architecture built from Long Short-Term Memory neural nets (LSTMs); the LSTMs learn how to summarize the neighborhood from data. We demonstrate the effectiveness of the proposed technique on a synthetic example and on real-world data related to crowdsourced grading, Bitcoin transactions, and Wikipedia edit reversions.
Estudio de la evolucion de las criptomonedas, desde el tradicional bitcoin al novedoso MUFG, haciendo especial mencion a la tecnologia “blockchain” y a sus potenciales utilidades.
Adem Efe Gencer, Robbert van Renesse, Emin Gün Sirer
The rise of blockchain-based cryptocurrencies has led to an explosion of services using distributed ledgers as their underlying infrastructure. However, due to inherently single-service oriented blockchain protocols, such services can bloat the existing ledgers, fail to provide sufficient security, or completely forego the property of trustless auditability. Security concerns, trust restrictions, and scalability limits regarding the resource requirements of users hamper the sustainable development of loosely-coupled services on blockchains. This paper introduces Aspen, a sharded blockchain protocol designed to securely scale with increasing number of services. Aspen shares the same trust model as Bitcoin in a peer-to-peer network that is prone to extreme churn containing Byzantine participants. It enables introduction of new services without compromising the security, leveraging the trust assumptions, or flooding users with irrelevant messages.
Early 1990s governments across the South have embarked on democratic decentralization reforms aimed at introducing and strengthening local governance because of its assumed potential to improve the delivery of public services and alleviate poverty. To comply with that international practice, in early 2000 Tanzania government decide embarked on an ambitious Local Government Reform Program that addressed Political decentralization. Political decentralization signaled the government’s commitment to enhance the decision making authority of local government councils on matters affecting local development including determining priorities for local development, land use, finance, service delivery and human resource management. This paper sought to find out whether the selected local government council led by councilors enjoys the development planning, and service delivery authority as established in the local government law. The findings have confirmed that the case study council enjoyed modest decision making authority in the areas of local development planning, selecting local development strategy, and enjoyed even greater authority over service delivery powers.
The blockchain is a distributed network that records digital transactions on a publicly-accessible ledger. This paper explores whether blockchain technology is a suitable platform for the preservation of digital signatures and key pairs (public and private keys). Conventional infrastructures use digital certificates, issued by certification authorities, to declare the authentication of key pairs and digital signatures. However, this paper suggests that the blockchain’s hash functions can replace those certificates on the grounds of better privacy, that the nature of the network removes the problem of a single point of failure and that hashing is a form of authentication that does not require trust in a third-party authority. This article was an appendix to the research paper, Blockchain Technology for Recordkeeping which is available in the Reports section at http://www.blockchainubc.ca/main/dissemination.
The well-being of the society depends on a number of metals, including base metals, precious metals and increasingly rare earth elements (REE). The usage of these metals increased in numerous applications, including electrical and electronic equipment (EEE), and their interrupted supply is at stake. There is an increasing interest in the secondary sources of these metals, particularly waste electrical and electronic equipment (WEEE) in order to compensate their potential supply deficit. This PhD thesis demonstrates the advantages and bottlenecks of biological and chemical approaches, as well as the advances and perspectives in the development of sustainable processes for metal recovery from WEEE. Furthermore, a novel process for the recovery of metals from WEEE is described, and a techno-economic assessment is given.\nDiscarded printed circuit boards (PCB) from personal computers (PC), laptops, mobile phones and telecom servers were studied. Following an extensive literature review, a novel characterization and total metal assay method was introduced and applied to waste board materials. Discarded PCB contained metals in the range of (%, by weight): copper (Cu) 17.6 - 39.0, iron (Fe) 0.7 - 7.5, aluminum (Al) 1.0 - 5.5, nickel (Ni) 0.2 - 1.1, zinc (Zn) 0.3 - 1.2, as well as gold (Au) (in ppm) 21 - 320. In addition, multi-criteria analysis (MCA) using the analytical hierarchical process (AHP) methodology was applied for selection of the best-suited technology. A proof-of-concept for a two-step bioleaching extraction is given, in which 98.4% and 44.0% of the Cu and Au, respectively, were extracted. The two-step extraction procedure was applied to the chemical leaching of metals from PCB. Cu leaching was carried in an acidic oxidative mixture of H2SO4 and H2O2, whereas Au was leached by S2O32− in a NH4+medium, catalyzed by CuSO4. Under the optimized conditions, 99.2% and 92.2% of Cu and Au, respectively, were extracted from the board material. Selective recovery of Cu from the bioleaching leachate using sulfidic precipitation and electrowinning is studied. Cu was selectively recovered on the cathode electrode at a 50 mA current density in 50 minutes, with a 97.8% efficiency and 65.0% purity. The techno-economic analysis and environmental sustainability assessment of the new technology at an early stage of development was investigated.
Today, with the use of Internet, a huge volume of data been generated in the form of transactions, logs etc. As assessed, 90% of total volume of data generated since evaluation of Computers is from last 3 years only. It's because of advancements in Data storage, global connectivity with Internet high speed, mobile applications usage and IoT. BigData Technologies aims at processing the BigData for deriving trend analysis and business usage from its BigData information. This paper highlights some of the security concerns that Hadoop implemented in its current version and need for some of the enhancements along with a new methodology such as Electronic Currency (BitCoin) and BlockChain functionality. And also emphasises on why and how BitCoin and BlockChain can fit in Hadoop Eco-Systems and their possible advantages and disadvantages. Especially, in validating and authorizing business transactions with some mathematical cryptographic techniques like hashcode with the help of BlockChain Miners.
This study aims to determine the factors that determine the Local Government Finance Accountability Reporting. Variabel Government Accountability Financial Reporting independently used in this study is the Fiscal Decentralization measured using Local Self-Reliance, Reliance Regions, the performance is measured using the ratio Effectiveness, Operational Expenditure Ratio, Ratio Shopping Capital and Regional Status. The dependent variable used in this study is the Local Government Finance Accountability Reporting measured using BPK Audit Report on the Financial Statements of Local Government in the form of an audit opinion. The samples were all over the city / regency in Central Java province with the study period between 2011-2013. Data were collected using purposive sampling. Based on these criteria, the total of 35 city / county elected as the population in this study. The analytical tool used is path analysis with SPSS version 16.0 Results of the study found that there is a significant positive effect between the Regional Autonomy and Accountability Financial Reporting Regions. Dependence area does not have a significant impact on Regions Financial Reporting Accountability. The effectiveness of significant negative effect on the Local Government Finance Accountability Reporting. Operating expenditure does not have a significant impact on Regions Financial Reporting Accountability. Capital spending has a significant positive effect on Regions Financial Reporting Accountability. Regional Status significant negative effect on Regions Financial Reporting Accountability. From the findings, we can conclude that the Regional Addiction and capital expenditures are a significant positive effect on Regions Financial Reporting Accountability. Regional and Operational Expenditure dependence there is no significant effect on the Local Government Financial Reporting Accountability however Effectiveness and Regional Status has a significant negative effect on Regions Financial Reporting Accountability.
The economic empowerment of urban local bodies is essential for the effective delivery of urban development programmes. These institutions are to be provided adequate financial resources to carry out various development activities in the cities. They are to be empowered to raise tax and collect fees from their municipal areas and also get due share of the grant-in-aid from the central and provincial governments in time. The financial aspects of intergovernmental relations veritably influence the nature, scope, and depth of democratic decentralization. Urban finances are critical elements in sustainable urban development. Moreover, effective and efficient urban financial management system will go a long way to improve the financial health of the local bodies. It would enhance their economic competitiveness; make the delivery of urban services effective; expand and diversify their revenue; and generate fund through capital investments. Thus, municipal finance is one of the most important areas of the urban development system. Smart urban finance is the key requirement without which the quality of life of people in urban areas cannot be effectively improved.
“Code is law” refers to the idea that, with the advent of digital technology, code has progressively established itself as the predominant way to regulate the behavior of Internet users. Yet, while computer code can enforce rules more efficiently than legal code, it also comes with a series of limitations, mostly because it is difficult to transpose the ambiguity and flexibility of legal rules into a formalized language which can be interpreted by a machine. With the advent of blockchain technology and associated smart contracts, code is assuming an even stronger role in regulating people’s interactions over the Internet, as many contractual transactions get transposed into smart contract code. In this paper, we describe the shift from the traditional notion of “code is law” (i.e., code having the effect of law) to the new conception of “law is code” (i.e., law being defined as code).
According to the World Economic Forum, by 2025 10% of global GDP will be stored on blockchains, a type of decentralised database and distributed shared ledger. Smart contracts are automated computable contracts that are executed in blockchains, with the benefit of removing intermediaries and reducing costs. The use cases in finance include: in cross-border payments, to capture obligations, minimize operational errors and expedite transfers; for property and casualty claims in insurance, to automate claims processing through third-party data sources and codification of business rules; for deposits and lending in syndicated loans, to facilitate real-time loan funding and automated servicing activities without intermediaries; for deposits and lending in trade finance, to automate the creation and management of credit facilities ultimately eliminating correspondent banks; for contingent convertible bonds in capital raising, to alert regulators when loan absorption needs to be activated, minimizing need for point-in-time stress tests; for compliance in investment management, to execute reporting and facilitate the automated creation of periodic filings; for proxy voting in investment management, to automate end-to-end confirmation by the validation of votes, increasing transparency; for asset rehypothecation in market provisioning, to enable the real-time reporting of asset history and the enforcement of regulatory constraints, including facilitating clearing and settlement to eliminate need for intermediaries and reduce settlement time; for equity post-trade in market provisioning, to simultaneously transfer equity and cash in real time, reducing the likelihood of errors impacting settlement.The policy implications introduced by decentralization require that economists and lawyers understand this technological shift, and more importantly, the risks related to tangible (e.g consensus selection as a security choice) and intangible (e.g contract incompleteness/code errors) factors. We demonstrate a decision making method where utility is measured by “levels of trust” using artifacts from fields finance applied to a portfolio of institutional smart contract companies. Expected utility is measured by mapping a demand vector field (the attention level), and funding by plotting a scalar field (the investment level); the associated risk exposure is implicit in the consensus mechanism tradeoffs, according to the progression of firms represented in the system of coordinates. The goal is to provide a device for portfolio analysis and construction. The data comes from a panel of 200 million internet users, and investment databases. The result is a comprehensive and scalable view of decentralised portfolios, inspired in the methods of behavioural finance.
The rapid development of the blockchain technology and its various applications has rendered it important to understand the guidelines for adopting it. The comparative analysis method is used to analyze different dimensions of the maturity model, which is mainly based on the commonly used capability maturity model. The blockchain maturity model and its adoption process have been discussed and presented. This study serves as a guide to institutions to make blockchain adoption decisions more systematically.
The problem of anomaly detection has been studied for a long time, and many Network Analysis techniques have been proposed as solutions. Although some results appear to be quite promising, no method is clearly to be superior to the rest. In this paper, we particularly consider anomaly detection in the Bitcoin transaction network. Our goal is to detect which users and transactions are the most suspicious; in this case, anomalous behavior is a proxy for suspicious behavior. To this end, we use the laws of power degree and densification and local outlier factor (LOF) method (which is proceeded by k-means clustering method) on two graphs generated by the Bitcoin transaction network: one graph has users as nodes, and the other has transactions as nodes. We remark that the methods used here can be applied to any type of setting with an inherent graph structure, including, but not limited to, computer networks, telecommunications networks, auction networks, security networks, social networks, Web networks, or any financial networks. We use the Bitcoin transaction network in this paper due to the availability, size, and attractiveness of the data set.
The problem of anomaly detection has been studied for a long time. In short, anomalies are abnormal or unlikely things. In financial networks, thieves and illegal activities are often anomalous in nature. Members of a network want to detect anomalies as soon as possible to prevent them from harming the network's community and integrity. Many Machine Learning techniques have been proposed to deal with this problem; some results appear to be quite promising but there is no obvious superior method. In this paper, we consider anomaly detection particular to the Bitcoin transaction network. Our goal is to detect which users and transactions are the most suspicious; in this case, anomalous behavior is a proxy for suspicious behavior. To this end, we use three unsupervised learning methods including k-means clustering, Mahalanobis distance, and Unsupervised Support Vector Machine (SVM) on two graphs generated by the Bitcoin transaction network: one graph has users as nodes, and the other has transactions as nodes.
Due sistemi a confronto. Il sistema di regolamento centralizzato. Il trading in un sistema a distributed ledger. Gestione collettiva della responsabilita. Il caso Estonia, una prima applicazione delle DLT in un contesto statale. Roadmap per l’introduzione. Il consenso tra gli osservatori. Sostenere il ledger. Bilanciare privacy e riconoscibilita.
Recently, fiscal decentralization, which involves the devolution of government fiscal responsibilities to lower levels of government, has been discussed in many developed and developing countries. In particular, the effect of fiscal decentralization on economic growth is a key issue in recent theoretical and empirical studies in public finance. The empirical evidences produce mixed results. In this study, the effect of fiscal decentralization on economic growth in a sample of several provinces will be explored. A province study offers several advantages: a bigger sample of data is available for province than for Indonesia; and panel data estimation is able to adjust the cultural, historical, and institutional differences and also to capture the local heterogeneities. By adopting a production-function-based estimation framework, the empirical estimation is done on a sample of cross section data that comprises of 26 province governments and the time series yearly data from 1992 to 2002. The Generalized Least Square method is used to test these data. The results indicate that: first, the fiscal decentralization variables (expenditure indicator) show the positive and significant coefficients, while, the revenue indicator shows the negative relationship with economic growth. Hence, several policy implications can be derived; i.e, the local government should be able: to increase their non taxes revenues; to create conducive conditions for capital inflows; and to develop a clear framework for fiscal decentralization assignment such as income redistribution and borrowingJEL classification: E60; E62; H62; H63; 04Keywords: province government financing; fiscal decentralization;localautonomy;fiscal policy; economic growth; cross-province data;
The dichotomy between pay-as-you-go (taxation financing) and pay-as-you-use (debt financing) methods of financing municipal projects, etc, is the area of concern in this paper. While there arc advantaees and disadvantages to both forms, debt financing carries a considerable amount of baggage known as interest. Interest or usury has been a concern of economic and religious thinkers through the ages. Given the potentially negative effect this has on the debtor, Indonesia is forewarned as it decentralizes fiscal administration to local governments. Besides reliance on taxation financing, an alternative public debt option is highlighted.
Moving IoT components from the cloud onto edge hosts helps in reducing overall network traffic and thus minimizes latency. However, provisioning IoT services on the IoT edge devices presents new challenges regarding system design and maintenance. One possible approach is the use of software-defined IoT components in the form of virtual IoT resources. This, in turn, allows exposing the thing/device layer and the core IoT service layer as collections of micro services that can be distributed to a broad range of hosts.
Harald Gjermundrød, Konstantinos Chalkias, Ioanna Dionysiou
The blockchain technology has emerged as a disruptive technology in recent years. The open and transparent nature of the distributed ledger, as supported by the blockchain technology, is an appealing factor to push this technology in applications with strong accountability and audit requirements such as cryptocurrency systems (i.e. Bitcoin) and ecommerce (i.e OpenBazaar). In order to guarantee the integrity of the distributed ledger, a set of miner nodes is in place that uses computing power to prove the authenticity of the ledger, in exchange for a small compensation fee. In this paper, alternative reward schemes for the miners are presented.