Nowadays, it has been recognized that blockchain can provide the technological infrastructure for developing decentralized, secure, and reliable smart energy grid management systems. However, an open issue that slows the adoption of blockchain technology in the energy sector is the low scalability and high processing overhead when dealing with the real-time energy data collected by smart energy meters. Thus, in this paper, we propose a scalable second tier solution which combines the blockchain ledger with distributed queuing systems and NoSQL (Not Only SQL database) databases to allow the registration of energy transactions less frequently on the chain without losing the tamper-evident benefits brought by the blockchain technology. At the same time, we propose a technique for tamper-evident registration of smart meters' energy data and associated energy transactions using digital fingerprinting which allows the energy transaction to be linked hashed-back on-chain, while the sensors data is stored off-chain. A prototype was implemented using Ethereum and smart contracts for the on-chain components while for the off-chain components we used Cassandra database and RabbitMQ messaging broker. The prototype proved to be effective in managing a settlement of energy imbalances use-case and during the evaluation conducted in simulated environment shows promising results in terms of scalability, throughput, and tampering of energy data sampled by smart energy meters.
The system that rewards data sharing users is meant to demonstrate Plasma as one of the solutions for scaling the Ethereum platform. Plasma is a set of rules and best practices which define the way sidechains are connected to the main Ethereum chain. The main chain, in this case, acts as a judge in any dispute that happens between users on the Plasma sidechain. The rewarding system is chosen for this demonstration because it would generate a large number of transactions in a production environment. In the real world, the data generated on the users' devices would create a constant stream of data which would have to be processed by a smart contract - an application running in the distributed environment of the Ethereum ecosystem. Because of the problems with transaction throughput Ethereum is facing all the time, a solution is needed to increase the number of transactions processed by the system per second.
Relying on the best practices defined by the rules of Plasma, the rewarding system, developed on a sidechain, provides the needed solution. Using the sidechain system, users can constantly share their data and get rewarded for it by the system which is validating the incoming data on a smart contract which is deployed on a sidechain. Users also have the ability to securely transfer their assets back from the Plasma sidechain, to the Ethereum main chain.
The practical part of this project is a system in a distributed environment, with high transaction throughput and a high level of security, which is guaranteed by the Ethereum platform.
Xiaojun Zhang, Jie Zhao, Chunxiang Xu, Hongwei Li · 6 authors
Wireless body area networks (WBANs) rely on powerful cloud storage services to manage massive medical data. As precise medical diagnosis analysis is heavily based on these medical data, any altered medical data may cause severe consequences, the integrity of outsourced medical data has become the most concerning security issue. Up to date, most existing public auditing mechanisms have been proposed to check the data integrity, but they could not achieve conditional identity privacy, any patient would not like others to know his/her real identity corresponding to certain serious disease, and some malicious patients should be revoked timely due to misbehaviors. Additionally, they are vulnerable to malicious auditors, by colluding with the cloud server to cheat patients. In this paper, we propose a conditional identity privacy-preserving public auditing (CIPPPA) mechanism for cloud-based WBANs. CIPPPA is the first public auditing mechanism achieving conditional identity privacy of patients in WBANs, the real identity of a patient is unknown to anyone in cloud-based WBANs other than the private key generator (PKG). We attempt to integrate Ethereum blockchain into CIPPPA, which gives assistance to patients for validating malicious auditing behaviors. Formal security analysis and performance evaluation demonstrate that CIPPPA is practical for cloud-based WBANs.
Francesco Longo, Letizia Nicoletti, Antonio Padovano, Gianfranco d’Atri · 5 authors
Despite Information and Communication Technologies (ICT) have reduced the information asymmetry and increased the degree of interorganizational collaboration, the companies participating a supply chain are less inclined to share data when information is sensible and partners cannot be fully trusted. In such a context, Blockchain is a decentralized certificate authority that may provide economic and operational benefits but companies operating in a supply chain claim to have little knowledge about Blockchain due to its novelty and to the lack of use cases and application studies. In this work, a software connector has been designed and developed to connect an Ethereum-like blockchain with the enterprises' information systems to allow companies to share information with their partners with different levels of visibility and to check data authenticity, integrity and invariability over time through the blockchain, thus building trust. In order to explore the potential of deploying the blockchain in a supply chain, a simulation model has been developed to recreate the supply chain operations and integrated with the blockchain through the same software connector to carry out a scenario statistical analysis. Application results shows how blockchain technology is a convenient instrument to overcome collaboration and trust issues in a supply chain, to increase the supply chain overall performance, to minimize the negative consequences of information asymmetry over the echelons of a supply chain but also to discourage companies from any misconduct (e.g. counterfeiting data or low data accuracy).
We present solc-verify, a source-level verification tool for Ethereum smart contracts. Solc-verify takes smart contracts written in Solidity and discharges verification conditions using modular program analysis and SMT solvers. Built on top of the Solidity compiler, solc-verify reasons at the level of the contract source code, as opposed to the more common approaches that operate at the level of Ethereum bytecode. This enables solc-verify to effectively reason about high-level contract properties while modeling low-level language semantics precisely. The contract properties, such as contract invariants, loop invariants, and function pre- and post-conditions, can be provided as annotations in the code by the developer. This enables automated, yet user-friendly formal verification for smart contracts. We demonstrate solc-verify by examining real-world examples where our tool can effectively find bugs and prove correctness of non-trivial properties with minimal user effort.
This chapter identifies and illuminates the feasible regulatory space to help understand how smart contracts for ODR platforms can possibly be regulated and embedded within current law systems. The chapter first defines smart contracts and explains their relationship to blockchain. It presents their capabilities and limitations and how they are different from conventional, more centralized approaches, thereby highlighting a unique contribution that is of great help for future ODR platforms: the enforced transparency of the dispute process. Based on this technical analysis, the chapter proposes an approach how smart contracts can be useful in ODR platforms as they are used today, such as the EU ODR platform, by outlining the principles applying to arbitrators and definitions of access control, e.g., the need for access for state actors. The chapter presents possible approaches to apply smart contracts to standardize the procedures of lodging cases on a large scale and handling disputes in an efficient manner. The proposals are based on lessons learnt in the last few years in the development of smart contracts on the Ethereum blockchain, currently the only major blockchain that supports smart contracts. The chapter concludes with an analysis of implications for future regulation and legal compliance.
Data privacy has been an important issue, especially over the last few years. Ethereum and other blockchains have had an ongoing problem with the lack of privacy. The European Union (EU) approved a law in 2016, the General Data Protection Regulation (GDPR), that is currently enforceable. It is considered to be one massive step towards protecting and preserving user privacy. Not only does it affect companies with offices in the EU but also organizations throughout the world that have users from the EU. Further, it mandates key obligations for organizations handling user data, in addition to introducing new rights for individuals - for instance, the right to erasure represents a challenge to the immutable nature of a blockchain.
Mark Mossberg, Felipe Andrés Manzano, Eric Hennenfent, Alex Groce · 8 authors
An effective way to maximize code coverage in software tests is through dynamic symbolic execution$-$a technique that uses constraint solving to systematically explore a program's state space. We introduce an open-source dynamic symbolic execution framework called Manticore for analyzing binaries and Ethereum smart contracts. Manticore's flexible architecture allows it to support both traditional and exotic execution environments, and its API allows users to customize their analysis. Here, we discuss Manticore's architecture and demonstrate the capabilities we have used to find bugs and verify the correctness of code for our commercial clients.
The subject of the research is the NEO and Ethereum cryptocurrencies. The relevance of the research is due to the following. First, these cryptocurrencies are expected to play the key role in establishing the future digital economy. Second, cryptocurrency developers are competing to gain leading positions in the development of financial technologies of the digital revolution. Third, the above cryptocurrencies are designed to perform almost identical functions, therefore, to determine the advantages of either of them, a comparative analysis is needed and appropriate conclusions for the Russian economy should be made. The purpose of the paper was to perform a comparative analysis of the Ethereum and NEO cryptocurrencies to identify trends in the digital economy of the future and determine the main targets to enable Russia’s entry into the top five largest world economies. The information sources include articles, books, regulations, departmental documents and conference materials on FinTech, crypto-markets and the digital economy. The research made it possible to reveal specific features of the cryptocurrencies and the corresponding digital platforms that are important for the development of the digital economy of the future. The goal of Ethereum developers is to create a platform for decentralized applications, based on which it will be possible to form a global, easy-to-access, free and reliable Internet of the future. The paper concludes that at present, the NEO has advantages over the Ethereum in terms of both the transaction speed and operational fitness for the development of prospective technologies of the digital economy. However, it may happen that in the near future, the Ethereum developers will be able to improve their blockchain technology so as to ensure the priority of their project in the competition for leadership in the development of the digital economy of the future. Given the contradictions revealed and taking into account the raw materials orientation of the Russian economy, a number of targets are proposed to bring Russia into the five largest world economies.
This research focuses on the decentralised distribution of solar energy between networks using IoT (Internet of Things) enabled devices and Blockchain technology. IoT provides a medium for software part to interact with the physical part which is energy and transmission grid. IoT connects the physical battery containing the energy to the cloud database which is then used to interact with the software. IoT also enables the transfer of energy through the physical medium on the command given by the user through the user application. To make the system decentralized, blockchain is used, which helps to connect all the users in the network where they can transact without the need of knowing each other or having the obligation of any intermediary. Decentralisation helps in achieving a system which doesn't require any middleman and works on the cumulative trust of the nodes - often referred to as the Consensus-Based Algorithm. There are a number of such algorithms but Proof of Work (PoW) and Proof of Stake (PoS) are widely used for blockchains. We suggest using the PoW algorithm. We need to take care if the certain conditions meet before enabling any user to transact. For such condition, we used the application logic on the server side to enable a valid transaction (similar to smart contracts on Ethereum). Blockchain also offers security, transparency, immutability and customer centricity to develop the most advanced and automated platform.
Blockchain je u proteklih nekoliko godina dobio široku pozornost zbog njegove primjene na kripto valutama i tehnologijama distribuiranih knjiga (Distributed Ledger), kao što su Bitcoin i Ethereum. Složena i decentralizirana priroda blockchain tehnologija otežava razumijevanje ponašanja pojedinih komponenata i njihovog učinka na blockchain sustav. Dolaskom novih konsenzus algoritama, kao što je Proof of Authority (PoA), razumijevanje ovog složenog sustava postaje izazovan zadatak. U ovom radu predlažemo PoASim, podesiv, diskretni simulacijski alat za simulaciju dvaju glavnih PoA algoritama, nazvanih Clique i Aura. PoASim može pomoći korisnicima da bolje razumiju temeljne slojeve Ethereum blockchain-a, kao i razumijevanje razlika konsenzusa i nedostataka između dva konsenzus algoritma. PoASim tako može poslužiti kao koristan alat za bolje razumijevanje ponašanja svakog konsenzusa pokretanjem simulacija s različitim parametrima i analizom ponašanja sustava.
Blockchain have received widespread attention over the past few years because of its application on cryptocurrencies and Distributed Ledger technologies, such as Bitcoin and Ethereum. Complex and decentralized nature of blockchain technologies makes it difficult to understand behaviors of individual components and their effect on the blockchain system. With the arrival of new consensus algorithms, such as Proof-of-Authority (PoA), understanding this complex system becomes a challenging task. In this thesis, we propose PoASim, configurable, discrete-event simulation tool for simulating two of the main PoA algorithms, named Clique and Aura. PoASim can help users better understand the underlying layers of the Ethereum blockchain, as well as understanding consensus differences and drawbacks between the two consensus algorithms. PoASim can thus serve as a useful tool for better understanding behavior of each consensus by running simulations with varying parameters and then analyzing the system behavior.
The automotive industry has seen an increased need for connectivity, both as a result of the advent of autonomous driving and the rise of connected cars and truck fleets. This shift has led to issues such as trusted coordination and a wider attack surface have come to light, leading to higher costs and bureaucratic interventions. Due to the increasing adoption of connected vehicles, as well as other connected infrastructure, trustless peer to peer systems including blockchain are being explored as potential solution to this efficiency problem. All the while, scalability is still a significant concern for industry players. Current blockchain based systems have difficulty scaling: Bitcoin can only process seven transactions per second (tx/s) whereas Ethereum's fifteen tx/s is not a major improvement. Combined with the high cost of consensus and low throughput, such platforms are unusable with the mobility sector. This paper will address the latest advances in the field that aim to resolve parts of this problem as well as inform its readers about the scalability technologies that could push blockchain automotive infrastructure into the mainstream. This paper will also introduce the theoretical tools and advancements that, if implemented, could bring the mobility industry closer toward adopting efficient, scalable, and cost effective decentralized solutions.
Since the invention of Bitcoin one decade ago, numerous cryptocurrencies have sprung into existence. Among these, proof-of-work is the most common mechanism for achieving consensus, whilst a number of coins have adopted "ASIC-resistance" as a desirable property, claiming to be more "egalitarian,"S where egalitarianism refers to the power of each coin to participate in the creation of new coins. While proof-of-work consensus dominates the space, several new cryptocurrencies employ alternative consensus, such as proof-of-stake in which block minting opportunities are based on monetary ownership. A core criticism of proof-of-stake revolves around it being less egalitarian by making the rich richer, as opposed to proof-of-work in which everyone can contribute equally according to their computational power. In this paper, we give the first quantitative definition of a cryptocurrency's \emph{egalitarianism}. Based on our definition, we measure the egalitarianism of popular cryptocurrencies that (may or may not) employ ASIC-resistance, among them Bitcoin, Ethereum, Litecoin, and Monero. Our simulations show, as expected, that ASIC-resistance increases a cryptocurrency's egalitarianism. We also measure the egalitarianism of a stake-based protocol, Ouroboros, and a hybrid proof-of-stake/proof-of-work cryptocurrency, Decred. We show that stake-based cryptocurrencies, under correctly selected parameters, can be perfectly egalitarian, perhaps contradicting folklore belief.
Today, the world is on the threshold of a digital revolution that will affect all spheres of public life. The application of cryptocurrencies and blockchain technology has gone a long way since its introduction. Now it has reached a new milestone as it gets implemented in the energy sector. Blockchain and cryptographic technology have the potential to radically change the energy industry of the usual. Blockchain and cryptocurrencies are changing the energy sector and in the article is considered how it will affect the energy industry. Blockchain systems and cryptocurrencies no longer require either intermediaries or a central authority. But it is still difficult today to put such models into practice. In addition, there are a number of legal and regulatory requirements that blockchain projects must also comply with. Cryptocurrency is one of the most relevant topics when it comes to digitalization. On the basis of the analysis of the foreign practice of the use of cryptocurrency in the electric power industry, the prospects of implementation of such projects for Ukraine and their legal support are analyzed. Emphasized the advantages of blockchain and cryptocurrencies and demonstrates the mechanism of their work. The situation regarding the definition of the legal status of cryptographic goods in foreign countries and Ukraine is analysed. The main points to be solved in the course of approval of the right regulation of cryptocurrencies in Ukraine are determined. Foreign and certain domestic experience of using the blockchain technology and cryptology in the field of electric power industry indicates the prospect of further development of this direction. In the implementation of such instruments,it seems that it will allow accelerating the payments in electricity supply relations, will allow them to be more transparent, and at the same time protected from unauthorized interference, enhance the culture of contractual relations. REFERENCES1. Maidanyk R.A. Virtualna valiuta v tsyvilnomu pravi Ukrainy: stan, tendentsii, perspektyvy. Visn. Nats. akad. prav. nauk Ukrainy. 2018. Vol. 25, No. 2. P. 114-129 [in Ukrainian].2. Husieva I.I., Petrova T.O. Tendentsii rozvytku kryptovaliut na rynku Ukrainy. Naukovyi visnyk Mizhnarodnoho humanitarnoho universytetu. 2017. Iss. 24 (1). P. 48050 [in Ukrainian].3. Lukianov V.S. Zarodzhennia rynku kryptovaliuty v informatsiino-merezhevii paradyhmi. Aktualni problemy ekonomiky. 2014. No. 8 (158). P. 4360441 [in Ukrainian].4. Svon M. Blokchejn: Shema novoj jekonomiki. M.: Olimp-biznes, 2017. 240 p. [in Russian].5. Blokchein — novi mozhlyvosti dlia vyrobnykiv ta spozhyvachiv elektroenerhii? Ohliad svitovoi elektroenerhetyky, pidhotovlenyi PwC. Pricewaterhouse Coopers International Limited (PwCIL), 2016. URL: https://www.pwc.ru/ru/publications/blockchain/blockchain_opportunity-for-energy-producers%20and-consumers_RUS.pdf [in Ukrainian].6. Directive (EU) 2015/849 of the European Parliament and of the Council of 20 May 2015 on the prevention of the use of the financial system for the purposes of money laundering or terrorist financing. EUR-Lex: Access to European Union law. URL: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex%3A32015L08497. Federal act on banks and savings banks. URL: https://www.admin.ch/opc/de/classifiedcompilation/19340083/index.html8. O razvitii cifrovoj jekonomiki: Dekret Prezidenta Respubliki Belarus' ot 21.12.2017 № 8. URL: http://president.gov.by/ru/official_documents_ru/view/dekret-8-ot-21-dekabrja-2017-g-17716/ [in Russian].9. Zelena knyha rehuliuvannia rynku kryptovaliut: Ofis efektyvnoho rehuliuvannia. Traven 2018. URL: https://cdn.regulation.gov.ua/fe/5b/20/42/regulation.gov.ua_Zelena-Knyha.-Rynok-Kryptovaliut.pdf [in Ukrainian].10. Bitcoins: Aufsichtliche Bewertung und Risiken für Nutzer. Bundesanstalt für Finanzdienstleistungsaufsicht. 19.12.2013. URL: https://www.bafin.de/SharedDocs/Veroeffentlichungen/DE/Fachartikel/2014/fa_bj_1401_bitcoins.html [in German].11. Blockchain: Hype or Innovation: CoinForum.de. 26.02.2016. URL: https://Bitcoinblog.de/2016/02/26/rwe-undslock-it-wollen-ethereum-fuer-elektroautos-nutzen/12. Kryptovaliuta SolarCoin ta soniachni elektrostantsii. "SolarCoin" Nova kryptovaliuta yaka stymuliuie montazh dzherel alternatyvnoi elektroenerhetyky. 17.01.2018. URL: https://prel.prom.ua/a322224-kriptovalyuta-solarcoinsonyachni.html [in Ukrainian].13. Pro obih kryptovaliuty v Ukraini: proekt Zakonu Ukrainy vid 06.10.2017 No. 7183. URL: http://w1.c1.rada.gov.ua/pls/zweb2/webproc4_1?pf3511=62684 [in Ukrainian].14. Pro stymuliuvannia rynku kryptovaliut ta yikh pokhidnykh v Ukraini: proekt Zakonu Ukrainy vid 10.10.2017 No. 7183-1. URL: http://w1.c1.rada.gov.ua/pls/zweb2/webproc4_1?pf3511=62710 [in Ukrainian].
The high demand for food makes it necessary to implement plant phenotyping processes into breeding programs to deal with global food security. Image-based plant phenotyping generates vast amounts of data. Traditionally, this data has been managed in a centralized manner requiring that an administrator grants access permissions. This approach has some limitations when sharing data; for instance, we cannot track whether data has been shared with the permission of the owner. This research proposes a blockchain-based system for data access control management in the field of image-based plant phenotyping. This system integrates Ethereum blockchain to allow users to be the administrators of their data. Thus, users can grant or deny permissions to access their data without relying on any central administrator. This system is part of the research work at the Plant Phenotyping and Imaging Research Centre (P2IRC) in Saskatoon, Canada.
Blockchains provide decentralised, tamper-free registries of transactions among partners that may not trust each other. For the scientific community, blockchain smart contracts have been proposed to decentralise and make more transparent multiple aspects of scholarly communications. We show how an Ethereum-based suite of smart contracts running on top of a Web-enabled governance framework can facilitate decentralised computation of citations that is trustworthy. We implement and evaluate Smart Papers, and extend it with a model for decentralised citation counts. We show how our approach complements current models for decentralised publishing and informetrics calculation, and analyse cost and performance implications.
Rewriting-history attacks are devastating for blockchain-based cryptocurrency systems. To deter such attacks, this paper introduces a new model utilizing a smart contract to effectively prevent such attacks from succeeding. Each node who creates a new block is required to register with the smart contract to get a voucher required for the subsequent block validation. We explain the flow of the proposed model and the algorithms of the smart contract. We have implemented this smart contract in the Solidity language and simulated on the Ethereum test network. We also present security and simulation results of the proposed model.
Smart contracts on a blockchain are programs running in a distributed, transparent, and trustless environment, being one of the major assets of this new technology. They give rise to innovative applications and business models, with their potential and lasting impact still open. In this situation, it is interesting to understand what smart contracts are actually doing. While public announcements, by their nature, make promises of what smart contracts might achieve, the openly available data of blockchains provides a more balanced view on what is actually going on. In this paper, we analyze the activities of smart contracts on the Ethereum blockchain, the most prominent platform for smart contracts with all blockchain data visible. However, contracts operate behind the scenes. Their activities are only accessible by looking beyond the mere blockchain data that records external transactions. We also use all internal messages caused by contracts interacting with other addresses. In particular, we investigate the activities of smart contracts in their quantitative and temporal aspects. Based on lifespan and activity patterns, we identify particular groups like mayflies, loners, breeders, busy bees, sleepers, self-destructed and bonkers contracts and visualize their temporal characteristics. To gain insights into the purpose of these smart contracts we perform a basic analysis of code and message content including deployment code. We consider data up to Ethereum block 6900000 (end of 2018).
Lots of privacy and security issues in the current cloud-based data markets will be eliminated by taking advantage of blockchain-based decentralized storage services, which can provide a new paradigm for safe data outsourcing and correct remote search. However, existing data markets are also questioned on their inflexible and opaque pricing, where the value of data ownership and the cost of query search are mixed. Thus, a better pricing model is necessarily needed in an emerging decentralized data market. In this paper, we envision an Ethereum-based data market, in which the pricing model for each query includes two parties: owner (paid for his data ownership) and miner (rewarded by query search). We study a new cooperative search scheme through a proxy to reduce cost on the client (user) side. Suppose each user query is charged based on the number of keywords in the query. The cost reduction is based on combining multiple queries into a group subject to the constraint that the resulting combined query is not significantly larger than any of its original query in terms of the number of keywords. The total price is based on total number of keywords in all groups. As the optimal grouping depends on the pricing of both owner and miner, we build a small testbed to analyze how price setting will affect grouping results. Since it is a cooperative model with shared resources, we also study various incentive properties on the client side, thereby yielding a cost sharing mechanism to split joint cost in a truth-revealing and fair manner.