The article is dedicated to the actual problems of creation, intervention and introduction of electronic money crypto-currency and blockchain technology at the modern stage. Rather narrow description is given to essence, the history of invention and the types of crypto currency (bit coin, ethereum, etc.,), advantages and defects of their use, the electronic wallet and its types, situation of the electronic money introduc tion in Georgia, the global crypto currency spread and the tendencies and prospective of its possible recognition, assessed is significance of the electronic money in manufacturing, based on the modern technical-technological achievements, money-reporting field, maximally just relations creation and by this - further growth of the economic development and accordingly the permanent enhancement of the living standards of the populations.
Yu Rang Park, Eunsol Lee, Wonjun Na, Sung-Jun Park · 6 authors
BACKGROUND: There are many perspectives on the advantages of introducing blockchain in the medical field, but there are no published feasibility studies regarding the storage, propagation, and management of personal health records (PHRs) using blockchain technology. OBJECTIVE: The purpose of this study was to investigate the usefulness of blockchains in the medical field in relation to transactions with and propagation of PHRs in a private blockchain. METHODS: We constructed a private blockchain network using Ethereum version 1.8.4 and conducted verification using the de-identified PHRs of 300 patients. The private blockchain network consisted of one hospital node and 300 patient nodes. In order to verify the effectiveness of blockchain-based PHR management, PHRs at a time were loaded in a transaction between the hospital and patient nodes and propagated to the whole network. We obtained and analyzed the time and gas required for data transaction and propagation on the blockchain network. For reproducibility, these processes were repeated 100 times. RESULTS: Of 300 patient records, 74 (24.7%) were not loaded in the private blockchain due to the data block size of the transaction block. The remaining 226 individual health records were classified into groups A (80 patients with outpatient visit data less than 1 year old), B (84 patients with outpatient data from between 1 and 3 years before data collection), and C (62 patients with outpatient data 3 to 5 years old). With respect to mean transaction time in the blockchain, C (128.7 seconds) had the shortest time, followed by A (132.2 seconds) and then B (159.0 seconds). The mean propagation times for groups A, B, and C were 1494.2 seconds, 2138.9 seconds, and 4111.4 seconds, respectively; mean file sizes were 5.6 KB, 18.6 KB, and 45.38 KB, respectively. The mean gas consumption values were 1,900,767; 4,224,341; and 4,112,784 for groups A, B, and C, respectively. CONCLUSIONS: This study confirms that it is possible to exchange PHR data in a private blockchain network. However, to develop a blockchain-based PHR platform that can be used in practice, many improvements are required, including reductions in data size, improved personal information protection, and reduced operating costs.
Matias Travizano, Carlos Sarraute, Gustavo Ajzenman, Martin Minnoni
Our aim is for Wibson to be a blockchain-based, decentralized data marketplace that provides individuals a way to securely and anonymously sell information in a trusted environment. The combination of the Wibson token and blockchain-enabled smart contracts hopes to allow Data Sellers and Data Buyers to transact with each other directly while providing individuals the ability to maintain anonymity as desired. Wibson intends that its data marketplace will provide infrastructure and financial incentives for individuals to securely sell personal information without sacrificing personal privacy. Data Buyers receive information from willing and actively participating individuals with the benefit of knowing that the personal information should be accurate and current.
Marco Conoscenti, Antonio Vetrò, Juan Carlos De Martin, Federico Spini · 6 authors
The Lightning Network (LN) is one of the most promising off-chain scaling solutions for Bitcoin, as it enables off-chain payments which are not subject to the well-known blockchain scalability limit. In this work, we introduce CLoTH, a simulator for HTLC payment networks, of which LN is the best working example. It simulates input-defined payments on an input-defined HTLC network and produces performance measures in terms of payment-related statistics, such as time to complete payments and probability of payment failure. CLoTH helps to predict issues that might arise in the development of an HTLC payment network, and to estimate the effects of an optimisation before deploying it. In upcoming works we'll publish the results of CLoTH simulations.
Purpose - This study conducts an analysis to reveal the interaction between Bitcoin and Exchange Rates to find out whether Bitcoin is becoming a substitution for the exchange rates.Methodology - To investigate the mutually interaction between the exchange rates and the Bitcoin, the interaction (relationship) between daily closing price of both exchange rates and Bitcoin was analyzed through the Var model. Thus, it was tried to show the sensitivity of the values of Bitcoin to the changes occured in the exchange rates.Findings - Based on Variance Decomposition analysis, BITCOIN and Euro can be considered as largely external variables and their prices are not significantly affected by USD. An interesting result in this study is that the USD exchange rate was found to be significantly sensitive to the Euro.Conclusion - Findings obtained from analysis show that Bitcoin and Excange Rates have not become an alternative tools for each other yet.
Rapid advancements in digitalization are reshaping global supply chains and transforming the current modus operandi of the procurement function within companies. Broadly, procurement logistics involves the exchange of a wide variety of data and information relating to suppliers and buyers. As the needs of companies become more complex, many disruptive innovations are adopted to support and advance procurement in terms of predictability, transactional automation and proactivity of supplier relationship management. These emerging technologies encompass big data analytics, robotics, internet of things (IoT), blockchain and smart contracts, etc. Therefore, this paper aims to explore the potentialities of these emerging technologies in activities pertaining to procurement and the main organizational barriers that stand against their wide-scale implementation.
This paper aims to draw a comparison among the top 5 cryptocurrencies available in India based on the market capitalisation rate. It also aims to highlight the pros and cons of each category of cryptocurrencies and preference for one particular cryptocurrency over the other. The paper also focuses on whether cryptocurrency is accepted over and above the traditional modes of transaction. The study of various characteristic features of the five cryptocurrencies has highlighted that each cryptocurrency is technically different as well as significantly different in terms of speed of transaction. The study of price fluctuation of each of the cryptocurrencies over the 6 month period starting from October 2017 till March 2018 has revealed that prices of all cryptocurrencies have gone down in the month of March whereas November and December have been the peak time for almost all cryptocurrencies.It is also concluded that although the strikingly high price of cryptocurrencies promises high returns, the reasons for not investing in cryptocurrency outweigh the reasons justifying investment in it.
This review presents and evaluates various formalisms for the purpose of modelling the semantics of financial derivatives contracts. The formalism proposed by Lee is selected as the best candidate among those initially reviewed. Further examination and evaluation of this formalism is done.
This is the first paper that estimates the price determinants of BitCoin in a Generalised Autoregressive Conditional Heteroscedasticity framework using high frequency data. Derived from a theoretical model, we estimate BitCoin transaction demand and speculative demand equations in a GARCH framework using hourly data for the period 2013-2018. In line with the theoretical model, our empirical results confirm that both the BitCoin transaction demand and speculative demand have a statistically significant impact on the BitCoin price formation. The BitCoin price responds negatively to the BitCoin velocity, whereas positive shocks to the BitCoin stock, interest rate and the size of the BitCoin economy exercise an upward pressure on the BitCoin price.
Ali Dorri, Clemence Roulin, Raja Jurdak, Salil S. Kanhere
Security is one of the fundamental challenges in the Internet of Things (IoT) due to the heterogeneity and resource constraints of the IoT devices. Device classification methods are employed to enhance the security of IoT by detecting unregistered devices or traffic patterns. In recent years, blockchain has received tremendous attention as a distributed trustless platform to enhance the security of IoT. Conventional device identification methods are not directly applicable in blockchain-based IoT as network layer packets are not stored in the blockchain. Moreover, the transactions are broadcast and thus have no destination IP address and contain a public key as the user identity, and are stored permanently in blockchain which can be read by any entity in the network. We show that device identification in blockchain introduces privacy risks as the malicious nodes can identify users' activity pattern by analyzing the temporal pattern of their transactions in the blockchain. We study the likelihood of classifying IoT devices by analyzing their information stored in the blockchain, which to the best of our knowledge, is the first work of its kind. We use a smart home as a representative IoT scenario. First, a blockchain is populated according to a real-world smart home traffic dataset. We then apply machine learning algorithms on the data stored in the blockchain to analyze the success rate of device classification, modeling both an informed and a blind attacker. Our results demonstrate success rates over 90\% in classifying devices. We propose three timestamp obfuscation methods, namely combining multiple packets into a single transaction, merging ledgers of multiple devices, and randomly delaying transactions, to reduce the success rate in classifying devices. The proposed timestamp obfuscation methods can reduce the classification success rates to as low as 20%.
Tiago Quaini, Alex Roehrs, Cristiano André da Costa, Rodrigo da Rosa Righi
Electronic health records (EHR) are usually maintained in a centralized way by health organizations, leaving aside an integration between different health organizations to view the complete health history of a given patient. This lack of EHR integration prevents patients and physicians to have a unified view of medical records, which are often stored in different health organizations. Recent studies have proposed using Blockchain technology in distributed architectures due to its security and integration properties. In this context, this article proposes an application architecture using Blockchain technology for distributed EHR integration, which is called UniRec (Unified Medical Records). In the proposed model we seek to understand its effectivity, performance and applicability, using a case study methodology. We developed a prototype, which is evaluated using a test scenario. The prototype proved to be effective for distributed EHR integration, allowing one healthcare institution to view an EHR previously added by different providers, after being granted permission. During the test scenario execution, we obtained an average response time of 2.77 seconds, 961.6 MiB of memory consumption, 21.5% CPU usage and a total disk usage of 34.6 MB. The results reinforce the potential and feasibility of employing Blockchain for managing and storing medical data.
Blockchain technology is a distributed electronic ledger of digital records, events or transactions that are cryptographically secure, extremely hard to forge, and updateable through a consensus protocol agreeable to all connected nodes. [1] The technology uses decentralized consensus algorithms to control database consistency. The database is purely distributed in nature and is shared to all nodes connected to the network. Transactions in the databases are bundled together for specified period of time to form a block of certain number of transactions.
David M. Maslove, Jacob Klein, M. Kathryn Brohman, Patrick Martin
BACKGROUND: Blockchain technology is emerging as an innovative tool in data and software security. OBJECTIVE: This study aims to explore the role of blockchain in supporting clinical trials data management and develop a proof-of-concept implementation of a patient-facing and researcher-facing system. METHODS: Blockchain-based Smart Contracts were built using the Ethereum platform. RESULTS: We described BlockTrial, a system that uses a Web-based interface to allow users to run trials-related Smart Contracts on an Ethereum network. Functions allow patients to grant researchers access to their data and allow researchers to submit queries for data that are stored off chain. As a type of distributed ledger, the system generates a durable and transparent log of these and other transactions. BlockTrial could be used to increase the trustworthiness of data collected during clinical research with benefits to researchers, regulators, and drug companies alike. In addition, the system could empower patients to become more active and fully informed partners in research. CONCLUSIONS: Blockchain technology presents an opportunity to address some of the common threats to the integrity of data collected in clinical trials and ensure that the analysis of these data comply with prespecified plans. Further technical work is needed to add additional functions. Policies must be developed to determine the optimal models for participation in the system by its various stakeholders.
With the rapid development of the Internet of things (IoT), more and more IoT devices are connected and communicate frequently. In this background, the traditional centralized security architecture of IoT will be limited in terms of data storage space, data reliability, scalability, operating costs and liability judgment. In this paper, we propose an new key information storage framework based on a small distributed database generated by blockchain technology and cloud storage. Specifically, all encrypted key communication data will be upload to public could server for enough storage, but the abstracts of these data (called "communication logs") will be recorded in "IoT ledger" (i.e., an distributed database) that maintained by all IoT devices according to the blockchain generation approach, which could solve the problem of data reliability, scalability and liability judgment. Besides, in order to efficiently search communication logs and not reveal any sensitive information of communication data, we design the secure search scheme for our "IoT ledger", which exploits the Asymmetric Scalar-product Preserving Encryption (ASPE) approach to guarantee the data security, and exploits the 2-layers index which is tailor-made for blockchain database to improve the search efficiency. Security analysis and experiments on synthetic dataset show that our schemes are secure and efficient.
Ali Dorri, Fengji Luo, Salil S Kanhere, Raja Jurdak · 5 authors
Security and privacy in Direct Load Control (DLC) is a fundamental challenge in smart grids. In this paper, we propose a blockchain-based framework to increase security and privacy of DLC. We propose a method whereby participating nodes share their data with the distribution company in an anonymous and secure manner. To reduce the associated overhead for data dissemination, we propose a hash-based transaction generation method. We also outline the DLC process for managing the load in consumer site. Qualitative analysis demonstrates the security and privacy of the proposed method.
Ali Dorri, Ambrose Hill, Salil S. Kanhere, Raja Jurdak · 6 authors
Blockchain is increasingly being used as a distributed, anonymous, trustless framework for energy trading in smart grids. However, most of the existing solutions suffer from reliance on Trusted Third Parties (TTP), lack of privacy, and traffic and processing overheads. In our previous work, we have proposed a Secure Private Blockchain-based framework (SPB) for energy trading to address the aforementioned challenges. In this paper, we present a proof-on-concept implementation of SPB on the Ethereum private network to demonstrates SPB's applicability for energy trading. We benchmark SPB's performance against the relevant state-of-the-art. The implementation results demonstrate that SPB incurs lower overheads and monetary cost for end users to trade energy compared to existing solutions.
With the rapid development of the Internet of things (IoT), more and more IoT\ndevices are connected and communicate frequently. In this background, the\ntraditional centralized security architecture of IoT will be limited in terms\nof data storage space, data reliability, scalability, operating costs and\nliability judgment. In this paper, we propose an new key information storage\nframework based on a small distributed database generated by blockchain\ntechnology and cloud storage. Specifically, all encrypted key communication\ndata will be upload to public could server for enough storage, but the\nabstracts of these data (called "communication logs") will be recorded in "IoT\nledger" (i.e., an distributed database) that maintained by all IoT devices\naccording to the blockchain generation approach, which could solve the problem\nof data reliability, scalability and liability judgment. Besides, in order to\nefficiently search communication logs and not reveal any sensitive information\nof communication data, we design the secure search scheme for our "IoT ledger",\nwhich exploits the Asymmetric Scalar-product Preserving Encryption (ASPE)\napproach to guarantee the data security, and exploits the 2-layers index which\nis tailor-made for blockchain database to improve the search efficiency.\nSecurity analysis and experiments on synthetic dataset show that our schemes\nare secure and efficient.\n
The article deals with ontological aspects of cryptocurrency, its classification characteristics and types. The questions related to the creation of a new instrument of monetary policy are studied. The authors carry out analysis of foreign and domestic scientific papers, international and state regulatory documents linked with cryptocurrencies. The study reveals the distinctive features of cryptocurrency from the concepts of ‘digital currency’ and ‘virtual currency’, as well as historical stages of their development.The authors describe characteristics of three main communication elements between the participants of operations with cryptocurrencies. The article discloses the model of decentralized digital currency schemes and their main characteristics. The paper presents the analysis of normative documents regulating the turnover of cryptocurrency in Ukraine and considers the problems of displaying transactions with cryptocurrencies in the accounting.The authors investigate the problems of cryptocurrency’s use as a full-fledged currency in contemporary economic conditions, in particular, the absence of a centralized cryptocurrency emission institutions, circulation control, transaction anonymity and insufficient of high liquidity, as well as substantial short-term leaps in its value.According to the results of the study the authors propose approaches of book-keeping for transactions with cryptocurrency in accounting for companies in Ukraine depending on the purpose of their use (purchase of a web-purse for operations with cryptocurrency, purch
The idea of big data has gained extensive attention from governments and academia all over the world. It is especially relevant for the establishment of a smart city environment combining complex heterogeneous data with data analytics and artificial intelligence (AI) technology. Big data is generated from many facilities and sensor networks in smart cities and often streamed and stored in the cloud storage platform. Ensuring the integrity and subsequent auditability of such big data is essential for the performance of AI-driven data analysis. Recent years has witnessed the emergence of many big data auditing schemes that are often characterized by third party auditors (TPAs). However, the TPA is a centralized entity, which is vulnerable to many security threats from both inside and outside the cloud. To avoid this centralized dependency, we propose a decentralized big data auditing scheme for smart city environments featuring blockchain capabilities supporting improved reliability and stability without the need for a centralized TPA in auditing schemes. To support this, we have designed an optimized blockchain instantiation and conducted a comprehensive comparison between the existing schemes and the proposed scheme through both theoretical analysis and experimental evaluation. The comparison shows that lower communication and computation costs are incurred with our scheme than with existing schemes.
Emission trading policy provides a new approach using economic incentives to control the environmental pollution efficiently. Legal polluters can trade emission permits with each other through a trusted trading system that lacks security and credibility due to its centralization nowadays. Permissioned blockchain utilize a decentralized way to store private data immutably, providing new approaches to solve those defects of the existing centralized systems. In this paper, we propose a Hyperledger-based Emission Trading System (HyperETS) on the permissioned blockchain. Using Hyperledger Fabric as the implementation platform, HyperETS integrates the fine-grained access control, distributed ledger, and consensus protocol, aiming to provide credible trading service for polluters. We achieve the business logic by designing the particular ledger structures and smart contract in blockchain. HyperETS stores all transactions immutably in a chain and makes it easy to share the data between organizations. Finally, several experiments are conducted to evaluate the performances of the proposed demonstration system.
Yuepeng Wang, Shuvendu K. Lahiri, Shuo Chen, Rong Pan · 7 authors
Ensuring correctness of smart contracts is paramount to ensuring trust in blockchain-based systems. This paper studies the safety and security of smart contracts in the \emph{Azure Blockchain Workbench}, an enterprise Blockchain-as-a-Service offering from Microsoft. As part of this study, we formalize \emph{semantic conformance} of smart contracts against a state machine model with access-control policy and develop a highly-automated formal verifier for Solidity that can produce proofs as well as counterexamples. We have applied our verifier {\sc VeriSol} to analyze {\it all} contracts shipped with the Azure Blockchain Workbench, which includes application samples as well as a governance contract for Proof of Authority (PoA). We have found previously unknown bugs in these published smart contracts. After fixing these bugs, {\sc VeriSol} was able to successfully perform full verification for all of these contracts.
Antonio Fernández Anta, Chryssis Georgiou, Nicolas Nicolaou
The various applications using Distributed Ledger Technologies (DLT) or blockchains, have led to the introduction of a new `marketplace' where multiple types of digital assets may be exchanged. As each blockchain is designed to support specific types of assets and transactions, and no blockchain will prevail, the need to perform interblockchain transactions is already pressing. In this work we examine the fundamental problem of interoperable and interconnected blockchains. In particular, we begin by introducing the Multi-Distributed Ledger Objects (MDLO), which is the result of aggregating multiple Distributed Ledger Objects -- DLO (a DLO is a formalization of the blockchain) and that supports append and get operations of records (e.g., transactions) in them from multiple clients concurrently. Next, we define the AtomicAppends problem, which emerges when the exchange of digital assets between multiple clients may involve appending records in more than one DLO. Specifically, AtomicAppend requires that either all records will be appended on the involved DLOs or none. We examine the solvability of this problem assuming rational and risk-averse clients that may fail by crashing, and under different client utility and append models, timing models, and client failure scenarios. We show that for some cases the existence of an intermediary is necessary for the problem solution. We propose the implementation of such intermediary over a specialized blockchain, we term Smart DLO (SDLO), and we show how this can be used to solve the AtomicAppends problem even in an asynchronous, client competitive environment, where all the clients may crash.