Blockchain, the foundation of Ethereum, has received greater attention on recent years as a decentralised and distributed public ledger technology that offers different properties like security, privacy, scalability and immutability during online data transactions, reduces cost of transactions, and enables verification and efficient exchange of personnel information across many computers without any trusted parties. The goal of this survey is to propel some methods in preserving user privacy during data transactions using Ethereum smart contract. We analysed the privacy challenges in blockchain and figured out the existing cryptographic mechanisms in preserving the transaction privacy. We also addressed some technique for simplifying claim settlement process in healthcare insurance. By using Ethereum blockchain via smart contract, current challenges in insurance such as being time-consuming, can be avoided thereby preventing insurance frauds and thus improving transparency to all members in-network. It also helps to avoid paper-based contracts, which are prone to errors, and removes the intermediaries. Furthermore, there is still a need to examine and consider future research in order to overcome privacy attacks when using blockchain.
N. Banupriya, G. Pooja, S. Nevetha, J. Roopini · 5 authors
In the expeditiously advancing technological world, with the advent of IoT and big data, every day new people and devices which store highly sensitive personal data are getting connected. For instance, your Google home is listening to you and collecting data, your Facebook knows a lot about you; Amazon's Alexa gets to know our everyday wants. This implies that our data is used to spy on us for advertising purposes, hence these siren servers make the overall profit off us. This paper throws light on developing a dApp (decentralised application) that could be used in a voting system. Everything around us is digitising which does not mean we are moving towards a safe and secured scheme, thus the revolutionary Blockchain technology is used to deploy an e-voting system (Giorgino, 2018) and this is done using the Ethereum Blockchain (Wang et al., 2018).
The emergence of smart contracts has increased the attention of industry and academia to blockchain technology, which is tamper-proofing, decentralized, autonomous, and enables decentralized applications to operate in untrustworthy environments. However, these features of this technology are also easily exploited by unscrupulous individuals, a typical example of which is the Ponzi scheme in Ethereum. The negative effect of unscrupulous individuals writing Ponzi scheme-type smart contracts in Ethereum and then using these contracts to scam large amounts of money has been significant. To solve this problem, we propose a detection model for detecting Ponzi schemes in smart contracts using bytecode. In this model, our innovation is shown in two aspects: We first propose to use two bytes as one characteristic, which can quickly transform the bytecode into a high-dimensional matrix, and this matrix contains all the implied characteristics in the bytecode. Then, We innovatively transformed the Ponzi schemes detection into an anomaly detection problem. Finally, an anomaly detection algorithm is used to identify Ponzi schemes in smart contracts. Experimental results show that the proposed detection model can greatly improve the accuracy of the detection of the Ponzi scheme contracts. Moreover, the F1-score of this model can reach 0.88, which is far better than those of other traditional detection models.
П А Команов, Х Ю Ревазов, Д А Тавасиев, Пальмов, С.В.
В настоящее время технологии блокчейн находят высокий спрос в разных сферах. Широкое применение находят и смарт-контракты, которые записываются в блокчейн. Наибольшую популярность на данный момент имеют приложения, написанные с помощью смарт-контрактов на платформе Ethereum. Смарт-контракты, как и обычные программы, подвержены различным уязвимостям. В статье будут рассмотрены серьезные уязвимости, методы и инструменты, которые были менее освещены в сферах информационной безопасности и IT, но имеющие огромный потенциал в области обеспечения безопасности смарт-контрактов. Основная цель данной статьи заключается в том, чтобы дать представление об актуальных и серьезных уязвимостях в смарт-контрактах Ethereum и на основе актуальных угроз подобрать актуальные методы по обеспечению безопасности смарт-контрактов на платформе Ethereum.
Yuichiro Chinen, Naoto Yanai, Jason Paul Cruz, Shingo Okamura
Ethereum smart contracts are programs that are deployed and executed in a consensus-based blockchain managed by a peer-to-peer network. Several re-entrancy attacks that aim to steal Ether, the cryptocurrency used in Ethereum, stored in deployed smart contracts have been found in the recent years. A countermeasure to such attacks is based on dynamic analysis that executes the smart contracts themselves, but it requires the spending of Ether and knowledge of attack patterns for analysis in advance. In this paper, we present a static analysis tool named RA (Re-entrancy Analyzer), a combination of symbolic execution and equivalence checking by a satisfiability modulo theories solver to analyze vulnerability of smart contracts to re-entrancy attacks. In contrast to existing tools, RA supports analysis of inter-contract behaviors by using only the Ethereum Virtual Machine bytecodes of target smart contracts, i.e., even without prior knowledge of attack patterns and without spending Ether. Furthermore, RA can verify existence of vulnerability to re-entrancy attacks without execution of smart contracts and it does not provide false positives and false negatives. We also present an implementation of RA to evaluate its performance in analyzing the vulnerability of deployed smart contracts to re-entrancy attacks and show that RA can precisely determine which smart contracts are vulnerable.
This paper commences by introducing the essentials of blockchain technology and then goes into how Ethereum blockchain revolutionized blockchain. Smart contracts are presented in the context of showing how they play an important role in implementing rules regarding the Ethereum blockchain, allowing the user to regulate digital assets. The standards used in the Ethereum blockchain to build Non-Fungible Tokens (NFTs) are discussed. The paper concludes by presenting the benefits of NFTs as well as the use of Ethereum blockchain for future applications.
Unlike Bitcoin which was designed as an alternative to national currency as a medium of exchange, Ethereum was originally intended to facilitate projects based on its own platform. However, as the popularity of Ethereum continued to grow, it began to compete with every other cryptocurrencies and has become the second largest cryptocurrency in the world. Thus, it becomes important to study ether, Ethereum’s currency, as a medium of exchange. In this research, we will employ several regression models, including two stage least square (2SLS), regression discontinuity, difference-in-difference, and autoregression, to study various factors influencing ether’s transaction value, which is a crucial indicator as a medium of exchange and try to predict its growth. Through this study, we can have a clearer and more profound understanding of Ethereum’s development process,as well as a basic estimate of its future development trend.
The Ethereum blockchain is an open-source, decentralized blockchain with functions triggered by smart contract and has voluminous real-time data for analysis using machine learning and deep learning algorithms. Ether is the cryptocurrency of the Ethereum blockchain. Ethereum virtual machine is used to run Turing complete scripts. The data set concerning a block in the Ethereum blockchain with a block number, timestamp, crypto address of the miner, and the block rewards for the miner are explored for K means clustering for clustering miners with a unique crypto address and their rewards. Linear regression and polynomial regression are used for the prediction of the next block reward to the miner. The Long ShortTerm Memory (LSTM) algorithm is used to exploit the Ether market data set for predicting the next ether price in the market. Every kind of price and volume for every four hours is taken for prediction. The root mean square error of 34.9% is obtained for linear regression, the silhouette score is 71% for K-means clustering of miners with same rewards, with the optimal number of clusters obtained by Gap statistic method.
Open access
Blockchain Technology Applications and Security
Brain Tumor Detection and Classification
Advanced Steganography and Watermarking Techniques
A secure, smart and peer-to-peer transactions framework can be developed by Blockchain. Blockchain has enormous potential to turn health care systems as a horizontal technology, which has changed many fields of industry. The aim of this article is to critically review 50 papers published between 2015 and 2020 on blockchain-based health systems. 36 of these were journal papers; 7 were from conferences, 4 were from various symposiums; 3 were from seminars and 1 chapter was written in the book. Three key questions will be answered in this report. Firstly, what are the emerging trends of blockchain application development in healthcare from a technical perspective? Secondly, in what ways will the systematic analysis presented here contribute to a better understanding of the potential for incorporating blockchain-based technologies into the healthcare domain? Third, what are the important challenges in adopting blockchain as a solution in the healthcare domain? The descriptive analysis contains in this article shows the statistical statistics on the strategies of these 50 papers reveal that many of the blockchain systems proposed are using privately held blockchain and Ethereum platforms. We also address possible emerging trends of blockchain application such as blockchain integration with artificial intelligence, cloud based solutions and parallel block chain architecture.
Raja Wasim Ahmad, Khaled Salah, Raja Jayaraman, Ibrar Yaqoob · 6 authors
The year 2020 has witnessed unprecedented levels of demand for COVID-19 medical equipment and supplies. However, most of today's systems, methods, and technologies leveraged for handling the forward supply chain of COVID-19 medical equipment and the waste that results from them after usage are inefficient. They fall short in providing traceability, reliability, operational transparency, security, and trust features. Also, they are centralized that can cause a single point of failure problem. In this paper, we propose a decentralized blockchain-based solution to automate forward supply chain processes for the COVID-19 medical equipment and enable information exchange among all the stakeholders involved in their waste management in a manner that is fully secure, transparent, traceable, and trustworthy. We integrate the Ethereum blockchain with decentralized storage of interplanetary file systems (IPFS) to securely fetch, store, and share the data related to the forward supply chain of COVID-19 medical equipment and their waste management. We develop algorithms to define interaction rules regarding COVID-19 waste handling and penalties to be imposed on the stakeholders in case of violations. We present system design along with its full implementation details. We evaluate the performance of the proposed solution using cost analysis to show its affordability. We present the security analysis to verify the reliability of the smart contracts, and discuss our solution from the generalization and applicability point of view. Furthermore, we outline the limitations of our solution in form of open challenges that can act as future research directions. We make our smart contracts code publicly available on GitHub.
Electronic Health Record (EHR) and its privacy have attracted widespread attention with the development of the healthcare industry in recent years. As locking medical data in a single healthcare center causes information isolation, healthcare centers are motivated to build medical data sharing systems. However, existing systems highly rely on the trusted centralized servers, which are vulnerable to distributed denial of service (DDoS) attacks and the single point of failure. Moreover, it is a non-trivial matter to authorize multiple users to search and access EHR in a privacy-preserving manner. In this paper, we propose MedShare, a decentralized framework for secure EHR sharing. Our design utilizes the smart contract technique of blockchain to establish a trusted platform for healthcare centers to share their encrypted EHR. Considering that fine-grained access control is essential in practical EHR sharing service, we devise a constant-size attribute-based encryption (ABE) scheme, where the access policy is embedded in search result on the blockchain. Besides, we propose an efficient scheme that enables authorized MedShare users to perform multi-keyword boolean search operations over encrypted EHR. We formally analyze the security strengths and implement the system prototype on Ethereum. Evaluation results demonstrate that MedShare is efficient for EHR sharing.
This paper inquires into how token economies come to be, or how they are constituted. In examining this question, we draw on the market-making literature in economic sociology and the literature on social imaginaries. Our point of departure is that instead of a market emerging from a bureaucracy, we investigate a market emerging from a blockocracy, which is a form of organising based on public, permissionless, decentralised, coin-based blockchains. We argue that Ethereum is a blockocracy out of which a token economy comes to be and that the particular form of that token economy is best understood through the notion of an imaginary. We describe the Ethereum imaginary on six dimensions with an associated image for each: technical (the world computer), financial (functional money), political (cypherpunk mutualists), ethical (public goods commonists), organisational (decentralist engineers) and aesthetic (playful creators).
Blockchain technology is considered the most relevant technology after the internet that revolutionizes many application domains. The first generation of BC technology, BC 1.0, is used for cryptocurrency purposes; the second generation, BC 2.0, as represented by Ethereum, is an open and decentralized platform empowering the running of decentralized applications (DApps) on top of BC as a new computing paradigm. Ethereum as a BC 2.0 leader has a large development community. Its open-source feature leads to the development of several emulation tools, simulators, TestNets, and security verification tools dedicated to Ethereum-based system performance analysis. Making an adequate decision regarding the choice of the most appropriate Ethereum tool responding to the requirement of a specific system or application still requires more investigation from researchers. In this regard, this chapter presents the characteristics of the most-used Ethereum simulators, emulators, and TestNets and provides comparative studies between Ethereum simulators, TestNets, and security verification tools.