BACKGROUND Personal health record (PHR) security, correctness, and protection are essential for health and medical services. Blockchain architecture can provide efficient data retrieval and security requirements. Exchangeable PHRs and the self-management of patient health can offer many benefits to traditional medical services by allowing people to manage their own health records for disease prevention, prediction, and control while reducing resource burdens on the health care infrastructure and improving population health and quality of life. OBJECTIVE This study aimed to build a blockchain-based architecture for an international health record exchange platform to ensure health record confidentiality, integrity, and availability for health management and used Health Level 7 Fast Healthcare Interoperability Resource international standards as the data format that could allow international, cross-institutional, and patient/doctor exchanges of PHRs. METHODS The PHR architecture in this study comprised 2 main components. The first component was the PHR management platform, on which users could upload PHRs, view their record content, authorize PHR exchanges with doctors or other medical health care providers, and check their block information. When a PHR was uploaded, the hash value of the PHR would be calculated by the SHA-256 algorithm and the PHR would be encrypted by the Rivest-Shamir-Adleman encryption mechanism before being transferred to a secure database. The second component was the blockchain exchange architecture, which was based on Ethereum to create a private chain. Proof of authority, which delivers transactions through a consensus mechanism based on identity, was used for consensus. The hash value was calculated based on the previous hash value, block content, and timestamp by a hash function. RESULTS The PHR blockchain architecture constructed in this study is an effective method for the management and utilization of PHRs. The platform has been deployed in Southeast Asian countries via the Asia eHealth Information Network (AeHIN) and has become the first PHR management platform for cross-region medical data exchange. CONCLUSIONS Some systems have shown that blockchain technology has great potential for electronic health record applications. This study combined different types of data storage modes to effectively solve the problems of PHR data security, storage, and transmission and proposed a hybrid blockchain and data security approach to enable effective international PHR exchange. By partnering with the AeHIN and making use of the network’s regional reach and expert pool, the platform could be deployed and promoted successfully. In the future, the PHR platform could be utilized for the purpose of precision and individual medicine in a cross-country manner because of the platform’s provision of a secure and efficient PHR sharing and management architecture, making it a reasonable base for future data collection sources and the data analytics needed for precision medicine.
Distributed ledger technologies (DLT) enable the creation of digital databases stored across multiple locations. In the most-advanced design of DLTs, blockchains record and publish transactions through a peer-to-peer and tamper-proof block structure, and operate securely through a consensus-based algorithm. Increasingly, DLTs and blockchain-based initiatives are deployed in the mineral sector to address the problem of conflict minerals, ensure respect for due diligence standards, and improve supply chain management and traceability. The fast adoption of this technology for governing natural resources by creating immutable digital records of sourcing and geological information engenders new opportunities and risks for mining communities across Africa. These include the creation, ownership and access of digital data, the participatory role of upstream actors, and the effects of monitoring and traceability for informal miners and the future of sustainable development in mining communities.
Investing into a new product or service is a high-risk, high-return activity. This is best symbolized by the observation that the return over investment distribution of startups is a power law. Introduction of new products or services to the market might fail to generate profit even though there is a demand. Early adopters are also penalized, as they often pay a high price for something which will end up being cheaper, and might lose their warranty if the firm goes bankrupt. Innovation is slowed down. We propose to equally redistribute part of the generated profit at the end of a predefined time period to previous customers using Ethereum smart contract. Because customers are aware of the amount they would get back, their behaviors will change. The return over investment distribution and therefore the risk and return balance of the firms will also be affected. We formally define both a classic market and a market that is using our proposed system, and present an architecture to deploy such system. A preliminary numerical simulation is provided.
We study the Bitcoin and Ether price series under a financial perspective. Specifically, we use two econometric models to perform a two-layer analysis to study the correlation and prediction of Bitcoin and Ether price series with traditional assets. In the first part of this study, we model the probability of positive returns via a Bayesian logistic model. Even though the fitting performance of the logistic model is poor, we find that traditional assets can explain some of the variability of the price returns. Along with the fact that standard models fail to capture the statistic and econometric attributes—such as extreme variability and heteroskedasticity—of cryptocurrencies, this motivates us to apply a novel Non-Homogeneous Hidden Markov model to these series. In particular, we model Bitcoin and Ether prices via the non-homogeneous Pólya-Gamma Hidden Markov (NHPG) model, since it has been shown that it outperforms its counterparts in conventional financial data. The transition probabilities of the underlying hidden process are modeled via a logistic link whereas the observed series follow a mixture of normal regressions conditionally on the hidden process. Our results show that the NHPG algorithm has good in-sample performance and captures the heteroskedasticity of both series. It identifies frequent changes between the two states of the underlying Markov process. In what constitutes the most important implication of our study, we show that there exist linear correlations between the covariates and the ETH and BTC series. However, only the ETH series are affected non-linearly by a subset of the accounted covariates. Finally, we conclude that the large number of significant predictors along with the weak degree of predictability performance of the algorithm back up earlier findings that cryptocurrencies are unlike any other financial assets and predicting the cryptocurrency price series is still a challenging task. These findings can be useful to investors, policy makers, traders for portfolio allocation, risk management and trading strategies.
In this explorative study we provide empirical insight into how organized crime offenders use IT to launder their money. Our empirical data consist of 30 large-scale criminal investigations into organized crime. These cases are part of the most recent, fifth data sweep of the Dutch Organized Crime Monitor (DOCM). We do not focus on cybercrime alone. Instead, we explore the financial aspects of criminal operations in a broad range of types of organized crime, i.e. from ‘traditional’ types of organized crime, such as offline drug smuggling, to cybercrime. Regarding the spending of criminal proceeds (consumption and investment), the analyses show several similarities and no major differences between traditional crime and cybercrime. When it comes to concealing criminal earnings (money laundering), we do see important differences. Financial innovation, such as the use of cryptocurrencies, seems to be limited to cases of IT-related crime. One of the most striking similarities between cybercrime and traditional crime is the offenders’ preference for cash. In the analysed cases, malware and phishing offenders as well as online drug traffickers change their digital currencies for cash, at least in part.
Yong Sauk Hau, Jae Min Lee, Jaechan Park, Min Cheol Chang
BACKGROUND: The recently developed blockchain technology uses a peer-to-peer network to distribute data to all participants for storage. This method enhances data safety, reliability, integrity, and transparency. To successfully introduce blockchain technology to medical data management, it is essential to obtain consent from medical doctors and patients. OBJECTIVE: The aim of this study was to examine medical doctors' and patients' attitudes toward the use of blockchain technology and interpret the findings within the framework of expectancy theory. METHODS: In this questionnaire survey, we examined medical doctors' (n=90) and patients' (n=90) attitudes toward the use of blockchain technology in the management and distribution of medical information. The questionnaire comprised 8 questions that assessed attitudes toward new means of managing and distributing medical information using blockchain technology. Responses were rated on a scale that ranged from 1 (very negative) to 7 (very positive). RESULTS: Medical doctors (mean 3.7-5.0) reported significantly more negative attitudes than patients (mean 6.3-6.8). Furthermore, self-employed doctors reported more negative attitudes than employed doctors and university professors. CONCLUSIONS: To successfully introduce blockchain technology to medical data management, it is necessary to promote positive attitudes toward this technology among medical doctors, especially self-employed doctors.
Rantai pasok finansial (Supply Chain Finance/SCF) merupakan topik baru dalam penelitian manajemen rantai pasok (Supply Chain Management). SCF bertujuan melakukan diversifikasi sumber pendanaan dari perusahaan dengan modal terbatas dan meningkatkan efisiensi keuangan seluruh jaringan rantai pasok perusahaan. SCF telah menjadi sumber pendanaan jangka pendek bagi ribuan usaha mikro, kecil dan menengah (UMKM). Penelitian tentang SCF yang ada sekarang ini masih menggunakan framework keuangan konvensional dan belum ada penelitian SCF yang menggunakan framework keuangan Islam. Penelitian ini bertujuan untuk mengembangkan framework dan system SCF berdasarkan prinsip- prinsip syariah Islam berupa platform crowdfunding syariah dengan menggunakan teknologi blockchain dan smart contract . Rancangan system yang dihasilkan pada penelitian ini menggunakan smart contract yang dijalankan menggunakan protocol Ethereum untuk mencegah adanya penipuan/penggelapan dan meningkatkan system keamanan dari platform yang dirancang, sesuai dengan karaktrist i k blockchain yang sangat sulit di - hack.
In the Bitcoin white paper, Nakamoto proposed a very simple Byzantine fault tolerant consensus algorithm that is also known as Nakamoto consensus. Despite its simplicity, some existing analysis of Nakamoto consensus appears to be long and involved. In this technical report, we aim to make such analysis simple and transparent so that we can teach senior undergraduate students and graduate students in our institutions. This report is largely based on a 3-hour tutorial given by one of the authors in June 2019.
Illicit crypto-mining leverages resources stolen from victims to mine cryptocurrencies on behalf of criminals. While recent works have analyzed one side of this threat, i.e.: web-browser cryptojacking, only commercial reports have partially covered binary-based crypto-mining malware.
A startling announcement came on a crisp, fall day in 2017: Sidewalk Labs, a sister company of Google, was awarded a contract to create a ‘smart city’ along a small stretch of Toronto’s largely con...
We implement hidden Markov models (HMMs) and hidden semi-Markov models (HSMMs) on Bitcoin/US dollar (BTC/USD) with the aim of market phase detection. We make analogous comparisons to Standard and Poor’s 500 (S and P 500), a benchmark traditional stock index and a protagonist of several studies in finance. Popular labels given to market phases are “bull”, “bear”, “correction”, and “rally”. In the first part, we fit HMMs and HSMMs and look at the evolution of hidden state parameters and state persistence parameters over time to ensure that states are correctly classified in terms of market phase labels. We conclude that our modelling approaches yield positive results in both BTC/USD and the S and P 500, and both are best modelled via four-state HSMMs. However, the two assets show different regime volatility and persistence patterns—BTC/USD has volatile bull and bear states and generally weak state persistence, while the S and P 500 shows lower volatility on the bull states and stronger state persistence. In the second part, we put our models to the test of detecting different market phases by devising investment strategies that aim to be more profitable on unseen data in comparison to a buy-and-hold approach. In both cases, for select investment strategies, four-state HSMMs are also the most profitable and significantly outperform the buy-and-hold strategy.
Blockchain is maintained as a global log between a network of nodes and uses cryptographic distributed protocols to synchronize the updates. As adopted by Bitcoin and Ethereum these update operations to the ledger are serialized, and executed in batches. To safeguard the system against the generation of conflicting sets of updates and maintain the consistency of the ledger, the frequency of the updates is controlled, which severely affects the performance of the system. This paper presents Converging Directed Acyclic Graph (CDAG), as a substitute for the chain and DAG structures used in other blockchain protocols. CDAG allows multiple parallel updates to the ledger and converges them at the next step providing finality to the blocks. It partitions the updates into non-intersecting buckets of transactions to prevent the generation of conflicting blocks and divide the time into slots to provide enough time for them to propagate in the network. Multiple simultaneous updates improve the throughput of CDAG, and the converging step helps to finalize them faster, even in the presence of conflicts. Moreover, CDAG provides a total order among the blocks of the ledger to support smart contracts, unlike some of the other blockDAG protocols. We evaluate the performance of CDAG on Google Cloud Platform using Google Kubernetes Engine, simulating a real-time network. Experimental results show that CDAG achieves a throughput of more than 2000 transactions per second and confirms them well in under 2 minutes. Also, the protocol scales well in comparison to other permissioned protocols, and the capacity of the network only limits the performance.
Blockchain technology, while commonly associated with cryptocurrencies, stands to bring radical structural change to the arts and creative industries. This paper presents a history, primer, and taxonomy of blockchain use cases in the arts and then explores the implications of blockchain in three regards: the blurring of the for-profit / nonprofit distinction, changes in the ownership structure of art, and potential for new structures of public and private support and related policy changes. These developments raise important questions of governance of a technology which requires expertise in cryptography, coding, and securities law for implementation. Ultimately, blockchain holds the potential to tip the role of the arts toward democratic availability through collective ownership structures or toward further commodification of cultural assets.
As the accounting profession is rapidly changing, faculty members are challenged with the task of incorporating emerging advances into the accounting curriculum in order to equip students for future success. There is little debate that cryptocurrency is prominent in the business world today, thus prompting attention for accounting professionals and educators is important. In this paper, we document our experiences in introducing cryptocurrencies to undergraduate financial accounting students with the goal of capturing their knowledge and measuring their perceptions of the impact digital currency holds in the current economic environment. To operationalize our research question, students were given a cryptocurrency assignment to complete outside of class and were asked a series of questions in the class period directly after the assignment was due. The results of our case study show that students became more aware of cryptocurrencies and accounting practices associated with them after their completion of this assignment and the vast majority of students found this knowledge would benefit them in their future careers.
Libra was presented as a cryptocurrency on June 18, 2019 by Facebook. On the same day, Facebook announced plans for Calibra, a subsidiary in charge of the development of an electronic wallet and financial services. In view of the primary risk of sovereignty posed by the creation of Libra, regulators and Central Banks quickly took very clear positions against the project and expressed a lot of questions focusing on regulation aspects and national sovereignty. The purpose of this paper is to provide a holistic analysis of the project encompassing several aspects of its implementation and the issues it raises. We address a set of questions that are part of the cryptocurrency environment and blockchain technology that support the Libra project. We describe the governance of the project based on two levels, one for the Association and the other for the Libra Blockchain. We identify the main risks considering at the same time political, financial, economic, technological and ethical risks. We emphasize the difficulty to regulate such a project as it will depend on several countries whose legislations are very different. Finally, the future of this kind of projects is discussed through the emergence of Central Bank Digital Currencies.
Gabriel Hogan, Sigma Dolins, Izzet F. Senturk, Ioannis Fyrogenis · 8 authors
In this paper two contemporary technological novelties are combined to introduce the concept of a blockchain-based MaaS, with the aim of pinpointing where and how business value can be created through data-based services of such a system. Towards this purpose, an integrated version of the Business Model Canvas is deployed, combining the advantages of the Lean Canvas and the Ethics Canvas. The overview of data flows among the versatile system stakeholders are outlined to highlight the potential benefits for diverse industries through sharing and collaboration.
As the number of Internet of Things (IoT) devices increases, services expand and illegal hacking and infringement methods become more sophisticated, an effective solution for blockchain technology is required as a fundamental solution to security threats. In this paper, we develop the security module of an IoT device based on blockchain technology that blocks hacking and information infringement and forms a multi-security blockchain system between the IoT device and the user device and we develop a user application. We contribute to addressing the security threats faced by IoT application services by developing a new method. In particular, we present some schemes for the development of a multi-security certification system based on blockchain for IoT security.
Legal qualification of bitcoin, cryptocurrencies and "private money" in general raises doubts. Although, economically speaking, these goods perform some of the functions of money, they are not considered as such under the Polish civil code. This led some authors to argue that the rules on performance (and breach) of monetary obligations would not be applicable to cryptocurrencies. However, such a conclusion could cause unacceptable results, e.g. allowing for circumvention of the mandatory rules on maximum interest for late payment. The author proposes a solution to this dilemma. Firstly, it is accepted that cryptocurrencies are not "money" in the meaning of the Polish Civil Code. Therefore, the rules governing performance of monetary obligations do not automatically apply to cryptocurrencies. Secondly, cryptocurrencies cannot also be subject to all rules governing non-monetary performance, as this would lead to results inconsistent with the legislative purpose underlying various provisions of law. To ensure effectiveness of such provisions, a hybrid approach should be adopted. In particular, where justified by its ratio legis, the respective provisions governing monetary obligations should be applied to cryptocurrencies mutatis mutandi.
In the Internet of Things (IoT) ecosystem, the volume of data generated by devices in the user’s environment is continually increasing and becoming of particular value. In such an environment the average user is bound to face considerable difficulties in understanding the size and scope of his/her collected data. However, the provisions of the European General Data Protection Regulation (GDPR) require data subjects to be able to control their personal data, be informed, and consent to its processing in an intelligible manner. This paper proposes ADVOCATE platform, a user-centric solution that allows data subjects to easily manage consents regarding access to their personal data in the IoT ecosystem. The proposed platform also assists data controllers to meet GDPR requirements, such as informing data subjects in a transparent and unambiguous manner about the data they will manage, the processing purposes, and periods. The integrity of personal data processing consents and the immutable versioning control of them are protected by a blockchain infrastructure. Finally, the paper provides a prototype implementation of the proposed platform that supports the main consents management functionality.
Md. Ratul Amin, Megat F. Zuhairi, Md. Nazmus Saadat
Distributed ledger technology is an immutable data storage and transparent system, which is a constituent component that empowers the Food supply Chain Management (FSCM). Due to the immutable data feature, the scalability of blockchain technology is quite a challenge. In essence, blockchain data may grow rapidly as compared to the existing approach, and such circumstances is an issue that need to be addressed. Also, high volumes of data process for each transaction verification couple with long period of time for computation, lead to high overhead and resource consumption. This study discusses improved methods to reduce the amount of data generated by system. The proposed method employs the header verification system for transaction to reduce data growth and data processing time. During transaction, this method will verify only the header file information with using Merkle tree. This system is able to store each transaction of a node and form blockchain. Subsequently, each node is capable to verify valid transactions only by use of header data without maintaining full data of blockchain. The expected outcome of the scheme is the significant decrease of data growth in blockchain.
The active development of cryptocurrencies in recent years allows iden-tifying the process of forming new class of alternative investment assets. There was formed a sample of cryptocurrencies based on criteria capitalization and historical returns for estimation investment risk of this asset class. The sample included 327 cryptocurrencies, each of which has a capitalization of more than $ 1 mln. Measurement of investment risk was carried out on the basis of five approaches. The first one is grounded on the variability indicators. The second approach includes risk assess-ment in the context of asymmetry. The third is based on the concept of capital formation as part of the risk measures VaR and CVaR. The fourth focuses on measuring sensitivity risk. The fifth approach supposes using the Hurst exponent to measure risk. Based on the measures of these approaches, a comprehensive risk assessment was carried out. To cluster cryptocurrencies by riskiness, indicators from each group were selected, to which the technique of Kohonen self-organizing map was applied. The result was a partition of cryptocurrencies into three clusters. The analysis of the results is proposed and the corresponding conclusions and recommendations are made. \nАктивний розвиток криптовалют в останні роки дозволяє ідентифікувати процес формування нового класу альтернативних інвестиційних активів. Для оцінки інвестиційного ризику цього класу активів у дослідженні була сформована вибірка криптовалют, заснована на критеріях капіталізації та історичної доходності. Вибірка включала 327 криптовалют, які мали капіталізацію більше 1 млн. дол. США. Вимірювання інвестиційного ризику здійснювалося на основі п’яти підходів. Перший з них заснований на показниках варіативності. Другий підхід включав оцінки ризику в контексті асиметрії. Третій ґрунтувався на концепції формування капіталу в межах мір ризику VaR та CVaR. Четвертий був сфокусований на ризику чутливості. П’ятий підхід передбачав використання для вимірювання ризику показника Херста. На основі мір із зазначених підходів було здійснено комплексне оцінювання ризику. Для кластеризації криптовалют за ризиковістю були вибрані індикатори з кожної групи, до яких була застосована технологія самоорганізаційних карт Кохонена. Результатом стало розбиття криптовалют у три кластера. Наведено аналіз отриманих результатів та зроблені відповідні висновки і рекомендації. \nАктивное развитие криптовалют за последние годы позволяет идентифицировать процесс формирования нового класса альтернативных инвестиционных активов. Для оценки инвестиционного риска этого класса активов в исследовании была сформирована выборка криптовалют, основанная на критериях капитализации и исторической доходности. Выборка включала 327 криптовалют, которые имели капитализацию больше 1 млн. дол. США. Измерение инвестиционного риска осуществлялось на основе пяти подходов. Первый из них основан на применении показателей вариативности. Второй подход включал оценки риска в контексте асимметрии. Третий основывался на концепции формирования капитала в рамках мер риска VaR и CVaR. Четвертый был сфокусирован на риске чувствительности. Пятый подход предполагал использование для измерения риска показателя Херста. На основе мер из указанных подходов была осуществлена комплексная оценка риска. Для кластеризации криптовалют по их рисковости были выбраны индикаторы из каждой группы, к которым была применена технология самоорганизующихся карт Кохонена. Результатом стало разбиение криптовалют на три кластера. Приведен анализ полученных результатов и сделаны соответствующие выводы и рекомендации.
Since their emergence, blockchain technologies have shown potential for financial inclusion and the formalization of remittances. Recently, regulators and practitioners have studied the capabilities of blockchain technologies to streamline and, potentially, replace the infrastructure underpinning cross-border payments and remittances, i.e., correspondent banking. Correspondent Banking Relationships, also called “Nostro-Vostro accounts,” are continuous bilateral arrangements that enable banks to provide services in countries where they do not directly operate. After the Global Financial Crisis, this infrastructure has undergone “de-risking,” i.e., a reduction of correspondent accounts and their concentration in fewer financial institutions, with especially detrimental effects on costs and speed of retail cross-border remittances. The existing literature has mostly focused on the point of sale of remittances, often overlooking correspondent banking. This paper, in contrast, connects remittances, blockchain technologies, and correspondent banking with the growing interest of critical social science in the significance of payment infrastructures for the constitution and configuration of money, finance, and markets. By unpacking the critical case of Ripple, this paper shows that blockchain applications to remittances focus on profits, risks, costs, interoperability, “trapped liquidity,” and “idle capital” in correspondent banking accounts, rather than on financial inclusion per se. In so doing, this paper contributes to critical social studies literature on the formalization of remittances, understood as the transformation of remittances into a market frontier. Blockchain applications are shown to foster, rather than resist, remittances formalization, and they are presently being incorporated into existing infrastructures, business models, and regulatory structures. Rather than representing radically alternative monetary systems, blockchain technologies are the latest iteration of technologies heralding frictionless capitalism. Lastly, this paper shows the tensions and ambiguities inherent to interoperability and formalization. Blockchain technologies are dynamic in a way that problematizes dichotomies such formal-informal and mainstream-alternative. Hence, rather than providing a quantitative assessment of the impact of blockchain technologies, this paper investigates the ambiguities and tensions in the political economy and imaginaries inscribed in the materiality and design of blockchain-enabled payment systems.
Penelitian ini bertujuan untuk menganalisis kinerja portofolio yang dibentuk antara cryptocurrency dengan indeks LQ45 apakah memiliki kinerja yang lebih baik daripada portofolio yang hanya dibentuk dari indeks LQ45 saja. Jenis data yang digunakan dalam penelitian ini yaitu data sekunder berupa time series dengan periode penelitian Juni 2016 sampai Juni 2019. Data dalam penelitian ini berupa data kuantitatif. Hasil penelitian menunjukkan bahwa cryptocurrency memiliki korelasi negatif dengan indeks LQ45 sehingga dapat dijadikan sebagai aset lindung nilai. Pengukuran kinerja portofolio diukur berdasarkan Sharpe index, Treynor index, Jensen index dan Sortino ratio. Secara singkat, hasil dari pengukuran kinerja portofolio dapat disimpulkan bahwa dengan melibatkan cryptocurrency ke dalam pembentukan portofolio akan menghasilkan kinerja portofolio yang lebih baik.Kata kunci : Portofolio, Lindung Nilai, Cryptocurrency , Indeks LQ45, DCC-GARCH.