Carlos Molina-Jiménez, Ioannis Sfyrakis, Linmao Song, Danny, Hazem · 5 authors
The hype about Bitcoin has overrated the potential of smart contracts deployed on-blockchains (on-chains) and underrated the potential of smart contracts deployed on-Trusted Third Parties (on-TTPs). As a result, current research and development in this field is focused mainly on smart contract applications that use on-chain smart contracts. We argue that there is a large class of smart contract applications where on-TTP smart contracts are a better alternative. The problem with on-chain smart contracts is that the fully decentralised model and indelible append-only data model followed by blockchains introduces several engineering problems that are hard to solve. In these situations, the inclusion of a TTP (assuming that the application can tolerate its inconveniences) instead of a blockchain to host the smart contract simplifies the problems and offers pragmatic solutions. The intention and contribution of this paper is to shed some light on this issue. We use a hypothetical use case of a car insurance application to illustrate technical problems that are easier to solve with on-TTP smart contracts than with on-chain smart contracts.
We study optimal smart contract design for monitoring an exchange of an item performed offline. There are two parties, a seller and a buyer. Exchange happens off-chain, but the status update takes place on-chain. The exchange can be verified but with a cost. To guarantee self-enforcement of the smart contract, both parties make a deposit, and the deposits must cover payments made in all possible final states. Both parties have an (opportunity) cost of making deposits. We discuss two classes of contract: In the first, the mechanism only interacts with the seller, while in the second, the mechanism can also interact with the buyer. In both cases, we derive optimal contracts specifying optimal deposits and verification policies. The gains from trade of the first contract are dominated by the second contract, on the whole domain of parameters. However, the first type of contract has the advantage of less communication and, therefore, more flexibility.
Blockchain and cryptocurrency represent groundbreaking innovations that are reshaping digital systems through decentralization, transparency, and enhanced security.This paper explores the fundamental methodology behind blockchain technology, including its distributed ledger system, consensus mechanisms, cryptographic foundations, and smart contract functionalities.It also delves into the role of cryptocurrency as a financial application of blockchain, examining its decentralized nature, transactional efficiency, and potential to disrupt traditional banking models.Real-world applications in sectors such as finance, healthcare, IoT, and supply chain management are analyzed, highlighting blockchain's versatility and value in promoting trust and data integrity.The paper further addresses the major challenges facing blockchain, including scalability, interoperability, regulatory concerns, and energy consumption, while also discussing emerging solutions and technological advancements aimed at overcoming these limitations.The study concludes that blockchain and cryptocurrency have the potential to fundamentally transform digital interactions, offering new possibilities for secure, autonomous, and transparent systems across diverse industries.
We conduct a detailed analysis of investors in successful initial coin offerings (ICOs). The average ICO has 4700 contributors. The median participant contributes small amounts and many investors sell their tokens before the underlying product is developed. Large presale investors obtain tokens at a discount and flip part of their allocation shortly after the ICO. ICO contributors lack the protections traditionally afforded to investors in early-stage financing. Nevertheless, returns 9 months after the ICO are positive on average, driven mostly by an increase in the value of the Ethereum cryptocurrency.
Santiago Bragagnolo, Matteo Marra, Guillermo Polito, Elisa Gonzalez Boix
Analysing the blockchain is becoming more and more relevant for detecting attacks and frauds on cryptocurrency exchanges and smart contract activations. However, this is a challenging task due to the continuous growth of the blockchain. For example, in early 2017 Ethereum was estimated to contain approximately 300GB of data [1], a number that keeps growing day after day. In order to analyse such ever-growing amount of data, this paper argues that blockchain analysis should be treated as a novel type of application for Big Data platforms. In this paper we explore the application of parallelization techniques from the Big Data domain, in particular Map/Reduce, to extract and analyse information from the blockchain. We show that our approach significantly improves the index generation by 7.77 times, with a setup of 20 worker nodes, 1 Ethereum node and 1 Database node. We also share our findings of our massively parallel setup for querying Ethereum in terms of architecture and the bottlenecks. This should help researchers setup similar infrastructures for analysing the blockchain in the future.
W hat are the long-run prospects of Bitcoin as an investment?The bullish case is that Bitcoin will appreciate indefinitely due to its capped supply and an ever-growing demand.The bearish case is that Bitcoin's price will fall to zero, as it's an intrinsically worthless asset.We think the future price path is more likely to remain bounded between these two extremes.Consider first the bullish case for Bitcoin.We think this idea is too optimistic even if one grants that its supply is fixed and its demand is likely to grow. 1 The U.S. dollar price of Bitcoin will also depend on how its exchange rate relative to other cryptocurrencies evolves over time in the face of an ever-expanding supply of alternative cryptocurrencies, which we refer to as Altcoin. 2 The bullish case assumes that the nominal exchange rate between Bitcoin vis-à-vis other cryptocurrencies will adjust in proportion to their relative supplies.That is, Bitcoin is expected to appreciate relative to its competitors or, equivalently, its market-capitalization share will stay constant over time.But must this necessarily be the case?Consider the following thought experiment.
Madeleine Maslin, Millicent Watt, Christopher Yong
This paper dissects the research methodologies implemented by the Research Team for the Smart Contracts Working Group (TC-307/IT-041 Blockchain and Distributed Ledger Technologies) in developing standards to inform best practice in the design and use of blockchain and distributed ledger technologies. In doing so, it explores the origins of blockchain standardisation and outlines the high-level methodology for conducting and delivering research in this rapidly evolving space.
Yan Zhuang, Lincoln Sheets, Zon‐Yin Shae, Yin-Wu Chen · 6 authors
Patient recruitment for clinical trials is known to be a challenging aspect of clinical research. There are multiple competing concerns from the sponsor, patient and principal investigator's perspectives resulting in most clinical trials not meeting recruitment requirements on time. Conducting under-enrolled clinical trials affects the power of conclusive results or causes premature trial termination. The Blockchain is a distributed ledger technology originally applied in the financial sector. Its features as a peer-to-peer system with publicly audited transactions, data security, and patient privacy are a good fit for the needs of clinical trials recruitment. The "Smart Contract" is a programmable self-executing protocol that regulates the blockchain transactions. Given current recruitment challenges, we have proposed a blockchain model containing multiple trial-based contracts for trial management and patient engagement and a master smart contract for automated subject matching, patient recruitment, and trial-based contracts management.
The relative low level of smart home system (SHS) device information security may threaten the privacy of users. In this paper, we propose a homomorphic consortium blockchain for SHS sensitive data privacy preserving (HCB-SDPP), which is based on the traditional smart home system. We add verification services, which are composed of verification nodes, to our model to verify working nodes and transactions in SHS. In order to record the SHS device information transaction, we propose a new block data structure based on homomorphic encryption (HEBDS). Using the HCB-SDPP model, we design an encrypted algorithm based on Paillier encrypted for privacy protection. To verify the validity of the HCB-SDPP model, we firstly encrypt sensitive data of all gateway peers and upload them to the consortium blockchain. Then, we validate the security of sensitive data after homomorphic encryption processing. In the experiment, we also design attack experiments to attack different types of peers on the consortium blockchain in the HCB-SDPP model. If these nodes are insecure, the influence on the whole model will be analyzed. The simulation result shows that the HCB-SDPP model can protect customer privacy more effectively than SHS.
Aiming at the current problems of security threats and privacy leak risks in the operation process of related data of intelligent logistics system, and the operation of system lacking of supervision and traceability, this paper proposes to use blockchain technology to resolve these problems. A scheme on applying blockchain in intelligent logistics system is proposed, including operation principle, consensus authentication mechanism, and data storage and access mechanism. By introducing and analyzing the related big data of intelligent logistics system, improving the scientific, rationality, and intelligence of the decision. The basic characteristic of blockchain is traceability. By constructing algorithm models, proposing the realization principles of consensus authentication mechanism. For different events, different “multi-authentication centers”, intelligent contracts, and blockchain systems are constructed, improving the efficiency and supervision of the operation of intelligent logistics system. By constructing the correlations between the fundamental data that corresponding to different blockchain, and the correlations between the fundamental data that corresponding to the same blockchain, making the related data easier to collect and analyze. By constructing the storage and access mechanism, ensuring the security and confidentiality of the operation data of intelligent logistics system. This paper has provided thought for the application research of intelligent logistics system based on blockchain, and has positive reference value and guiding significance to the development of blockchain application research.
A Potential solution for solving forensic is the use of blockchain in software-defined networking (SDN). The blockchain is a distributed peer-to-peer network that can be utilized on SDN-based Internet of Things (IoT) environments for security provisioning. Hence, to meet some challenges in digital forensics such as data integrity, evidence deletion or alteration, blockchain is used. However, some problems such as poor attack detection and slow processing existed in previous works. To address these issues, an efficient forensics architecture is proposed in SDN-IoT that establishes the Chain of Custody (CoC) in blockchain technology. The proposed SDN-based IoT architecture is initiated with flow table rules on switches for the three different traffics Voice over Internet Protocol (VoIP), File Transfer Protocol (FTP), and Hyper Text Transfer Protocol (HTTP). In this work, overloaded switches migrate the packets to nearby switches to balance the packet flow. The packets disobeying flow rules will be discarded by switches. The blockchain-based distributed controller in this forensic architecture is designed to use the Linear Homomorphic Signature (LHS) algorithm for validating users. Each controller is fed with a classifier that uses the Neuro Multi-fuzzy to classify malicious packets based on packet features. The logs of events are used and stored on the blockchain in the proposed SDN-IoT architecture. We evaluated the performance of our forensic architecture and compared it to the existing model using various performance measures. Our evaluation results demonstrate performance improvement by reducing delay, response time and processing time, increasing throughput, accuracy, and security parameters.
In Ecuador, the City of Ambato has a public transport system dependent exclusively on oil derivatives. The Directorate of Traffic, Transport and Mobility Decentralized Autonomous Government Municipality of Ambato, GADMA, is responsible for the planning, organization and regulation of traffic of interparochial, intercantonal and urban land transport throughout the territory comprising the jurisdiction of the Ambato Canton. The Directorate of Traffic, Transport and Mobility prepares and signs the contracts of operation for the public transport in the city of Ambato. In this paper, a comparative analysis of the energy consumption, economic costs and environmental impact between fossil and electric buses for the urban public transport of the city of Ambato is evaluated. This study is based on information provided by the operating contracts of the Directorate of Traffic, Transport and Mobility of the Municipality of Ambato, on simulation of urban transport routes in ArcGIS software and on technical characteristic of fossil and electric buses provided by manufacturers.
With the appearance of Bitcoin, the blockchain technology behind it has attracted attention from banks, companies, and entrepreneurs from different fields. Many new blockchain technology related projects and companies are started in financial service and others , such as data storage, supply chain, internet of things (IoT) and copyright protection as the valuable features including decentralization, transparency, security, and immutability. The work of blockchain technology can be used to reduce the costs associated with making decision and improve the efficiency of implementation by means of decentralized autonomous organizations (DAOs) which are the products of decentralization management. This paper is to analyze the pros and cons of decentralization management based on blockchain technology with an empirical study of blockchain projects and companies in different industries for a better understanding of decentralization management, and find better ways of decentralization management in blockchain projects and managing decentralized autonomous organizations.
The purpose of the article is to study the theoretical foundations of decentralization, to analyze the indicators of the efficiency of cash management and to identify problems that have arisen as a result of the reform of intergovernmental fiscal relations. The article deals with problems of functioning of local budgets and regulation of intergovernmental fiscal relations under conditions of budget decentralization. The main directions of the budget policy introducing a new mechanism of budget regulation and equalization have been described. Suggestions for the functioning of local finance have been provided. The problems of intergovernmental financing have been identified and ways of their solution have been proposed. It has been noted that as a result of the decentralization process, the mechanism of the use of monetary resources has changed, therefore, an analysis of the efficiency of budget filling and rational use of budget funds is necessary to assess the actual state of affairs. The object of the study was the united territorial communities of Ukraine and their structure on subsidization in the conditions of modern reforms. On January 1, 2019, 876 OTGs were created in Ukraine as a result of the association of 4010 territorial communities (36.6% of all territorial communities), which covers 37.6% of the country’s territory. Elements of scientific novelty are developed criteria, which are isolated according to the results of the research: the basic grant should contribute to the fiscal capacity of local budgets; the amount of transfers must correspond to the financial security of the macroeconomic financial stability of the region and promote its economic growth; the system of intergovernmental transfers should stimulate local authorities to form their own revenues in local budgets; the transfer system should provide coverage of vertical and horizontal imbalances. It has been determined that the basis of intergovernmental relations should be the volume of transfer payments to certain territorial units, which should take into account such indicators as real incomes and the amount of substantiated expenditures. It has been concluded that the system of intergovernmental transfers should stimulate local authorities to form their own revenues in local budgets. Further research will be aimed at deepening the analysis of the impact of decentralization on the incomes and expenditures of territorial communities in the Transcarpathian region
The evolution of the energy production and distribution towards innovative decentralized models, dictates the introduction of emerging technologies to transform the conventional energy sector into smart