Elnaz Rabieinejad, Abbas Yazdinejad, Reza M. Parizi
Blockchain technology has found extensive applications in recent years, especially in financial and currency exchange applications, due to improved trustworthiness and security. Although blockchain technology improves security by design, it is not immune to security threats and vulnerabilities. Ethereum, as a decentralized, open-source blockchain, has shown high growth and widespread adoption in recent years, however, there is a wide range of vulnerability, security risks, and also attacks around it. To tackle such issues, machine learning could be a viable solution for threat hunting in the Ethereum blockchain. Machine learning algorithms, by analyzing the behav-ioral patterns, can achieve an insight for threat hunting. In this paper, we proposed a deep learning-based model for Ethereum threat hunting. The model applies a deep neural network for attack detection and uses a combination of machine learning algorithms (unsupervised with supervised algorithms) for attack classification. The performance evolution of the proposed model in terms of accuracy presents 97.72 % in Ethereum attack detection and 99.4% in attack classification.
Current advances in information technology have brought about significant changes, including ways to carry out elections using computer technology known as e-voting. Blockchain underlies the popularity of the digital currency Bitcoin and some other digital money, sparking the start of a new era of Internet use, including electronic voting (e-voting) system. In this work, we proposed designing and implementing an evoting system powered by the Ethereum blockchain. We used real-world data from the Indonesian Election Commission (KPU) with 26 candidates and 15,725 voters from the Jelupang sub-district. The testing and evaluation results using three miners in the blockchain show that the system could commit around 23 transactions per second. All 15,725 votes are committed to the blockchain successfully within 12.75 minutes. The total time required for creating all blockchain accounts is 13.4 hours.
Youssef Faqir-Rhazoui, Javier Arroyo, Samer Hassan
Abstract Blockchain technology has enabled a new kind of distributed systems. Beyond its early applications in Finance, it has also allowed the emergence of novel new ways of governance and coordination. The most relevant of these are the so-called Decentralized Autonomous Organizations (DAOs). DAOs typically implement decision-making systems to make it possible for their online community to reach agreements. As a result of these agreements, the DAO operates automatically by executing the appropriate portion of code on the blockchain network (e.g., hire people, delivers payments, invests in financial products, etc). In the last few years, several platforms such as Aragon, DAOstack and DAOhaus, have emerged to facilitate the creation of DAOs. As a result, hundreds of these new organizations have appeared, with their communities interacting mediated by blockchain. However, the literature has yet to appropriately explore empirically this phenomena. In this paper, we aim to shed light on the current state of the DAO ecosystem. We review the three main platforms nowadays (Aragon, DAOstack, DAOhaus) which facilitate the creation and management of DAOs. Thus, we introduce their main differences, and compare them using quantitative metrics. For such comparison, we retrieve data from both the main Ethereum network ( mainnet ) and a parallel Ethereum network ( xDai ). We analyze data from 72,320 users and 2,353 DAO communities in order to study the three ecosystems across four dimensions: growth, activity, voting system and funds. Our results show that there are notable differences among the DAO platforms in terms of growth and activity, and also in terms of voting results. Still, we consider that our work is only a first step and that further research is needed to better understand these communities, and evaluate their level of accomplishment in reaching decentralized governance.
Kai Li, Yuzhe Tang, Jiaqi Chen, Yibo Wang · 5 authors
Ethereum relies on a peer-to-peer overlay network to propagate information. The knowledge of Ethereum network topology holds the key to understanding Ethereum's security, availability, and user anonymity. From a measurement perspective, an Ethereum network's topology is routing-table information hidden inside individual Ethereum nodes, measuring which poses challenges and remains an open research problem in the existing literature. This paper presents TopoShot, a new method uniquely repurposing Ethereum's transaction replacement/eviction policies for topology measurement. TopoShot can be configured to support Geth, Parity, and other major Ethereum clients. As validated on local nodes, TopoShot achieves 100% measurement precision and high recall 88% - 97%. To efficiently measure the large Ethereum networks in the wild, we propose a non-trivial schedule to run pair-wise measurements in parallel. To enable ethical measurement on Ethereum mainnet, we propose workload-adaptive configurations of TopoShot to minimize the service interruption to target nodes/network. We systematically measure a variety of Ethereum networks and obtain new knowledge including the full-network topology in major testnets (Ropsten, Rinkeby and Goerli) and critical sub-network topology in the mainnet. The results on testnets show interesting graph-theoretic properties, such as all testnets exhibit graph modularity significantly lower than random graphs, implying resilience to network partitions. The mainnet results show biased neighbor selection strategies adopted by critical Ethereum services such as mining pools and transaction relays, implying a degree of centralization in real Ethereum networks.
Çin, ilk SARS-CoV-2 (COVID-19) vakasını 31.12.2019 tarihinde Dünya Sağlık Örgütü'ne (DSÖ) bildirmiştir. Bununla birlikte söz konusu virüs kısa sürede Dünya'da 200'den fazla ülkeye yayılmıştır. 07.04.2021 tarihi itibariyle Dünyada 133 milyondan fazla vaka tespit edilirken, yaklaşık 2.9 milyon kişi hayatını kaybetmiştir. Pandemi koşullarında hükümetler vatandaşlarını korumak için farklı politikalar izlediler. Pandemi, bu ülkelerdeki sağlık sistemine ek olarak borsaları ve altın, petrol, kripto para gibi çeşitli küresel varlıkları da etkilemiştir. Bu çalışmada, 26.06.2018 - 07.04.2021 dönemi için piyasa değeri en yüksek olan kripto para birimlerinde fiyat balonlarının varlığının incelenmesi amaçlanmaktadır. Bu çalışma kapsamında, pandemi öncesi ve pandemi döneminde on kripto para birimindeki fiyat balonlarının araştırılması için SADF testi uygulanmıştır. Buna göre, on kripto para biriminden sekizinin fiyat balonuna sahip olduğu tespit edilmiştir. Pandemi öncesi dönemde en yüksek fiyat balonu sayısının toplam 84 işlem günü ile Binance Coin'de görüldüğü belirlenmiştir. Sırasıyla, Bitcoin, Chainlink (Bitcoin ile aynı gün sayısı), Litecoin ve Tether bu kripto para birimini takip etmiştir. Bununla birlikte, COVID-19 salgınında işlem günü bazında en yüksek fiyat balonu, toplam 230 gün ile Theta'da görülmüştür. Pandemi döneminde, Chainlink, Bitcoin, Ethereum, Cordano, Binance Coin ve Litecoin, Theta'yı sırasıyla 183, 140, 104, 94, 66 ve 28 işlem günü ile takip etmiştir. Fiyat balonlarının yaklaşık yüzde yetmiş beşi pandemi döneminde görülmüştür. Bu sonuçlar, kripto para birimlerinin yeni yatırımlar için spekülatif varlıklar olduğunu göstermektedir. Tüm analiz dönemi değerlendirildiğinde ise toplam 234 gün ile Chainlink'te en yüksek fiyat balonu tespit edilmiştir. Ayrıca, Bitcoin 131 gün ile aralıksız en uzun fiyat balonunu göstermiş, Theta ve Ethereum bu kripto parayı takip etmiştir.
Umi Marfuah, Yandra Arkeman, a Machfud, Indah Yuliasih
Indonesians are the worlds largest chilli enthusiasts, mostly consuming fresh chilli. Because of chilli products generally perishable characteristics, its price has become unstable.The growing number of agricultural safety and risk issues has revealed a substantial need for an effective traceability solution, which serves as an essential agricultural supply chain method to ensure adequate product safety. Blockchain is the technology that disrupts goods in supply chains of agriculture and offers a revolutionary solution for their traceability. Today, farm supply chains are a dynamic ecosystem with multiple stakeholders, making it difficult to verify a range of main parameters, including the country of origin, stage in crop production, quality compliance, and yield monitoring. This paper suggests using the Ethereum blockchain and intelligent contracts to monitor and traceability operations across the agricultural supply chain effectively. Our proposed solutions remove the need for trustworthy centralized subjects, intermediaries, transaction records, performance, and security enhancements that are highly integral, accurate, and stable. The approach suggested focuses on using intelligent agreements to monitor and manage all communications and transactions between all actors in the supply chains ecosystem. All transactions are registered in the immutable blockchain lead with connections to a decentralized system (IPFS), ensuring the ecosystem is safe, confident, reliable and booming for everyones high degree of transparency and traceability.
A key component of blockchain technology is the ledger, viz., a database\nthat, unlike standard databases, keeps in memory the complete history of past\ntransactions as in a notarial archive for the benefit of any future test. In\nsecond-generation blockchains such as Ethereum the ledger is coupled with smart\ncontracts, which enable the automation of transactions associated with\nagreements between the parties of a financial or commercial nature. The\ncoupling of smart contracts and ledgers provides the technological background\nfor very innovative application areas, such as Decentralized Autonomous\nOrganizations (DAOs), Initial Coin Offerings (ICOs) and Decentralized Finance\n(DeFi), which propelled blockchains beyond cryptocurrencies that were the only\nfocus of first generation blockchains such as the Bitcoin. However, the\ncurrently used implementation of smart contracts as arbitrary programming\nconstructs has made them susceptible to dangerous bugs that can be exploited\nmaliciously and has moved their semantics away from that of legal contracts. We\npropose here to recompose the split and recover the reliability of databases by\nformalizing a notion of contract modelled as a finite-state automaton with\nwell-defined computational characteristics derived from an encoding in terms of\nallocations of resources to actors, as an alternative to the approach based on\nprogramming. To complete the work, we use temporal logic as the basis for an\nabstract query language that is effectively suited to the historical nature of\nthe information kept in the ledger.\n
David Opeoluwa Oyewola, Emmanuel Gbenga Dada, Juliana Ngozi Ndunagu, Daniel Eneojo Emmanuel
In the wake of recent pandemic of COVID-19, we explore its unprecedented impact on the demand and supply of cryptocurrencies’market using machine learning such as Naïve Bayes (NB), Decision Trees (C5), Decision Trees Bagging (BG), Support Vector Machine (SVM), Random Forest (RF), Multinomial Logistic Regression (MLR), Recurrent Neural Network (RNN), Long Short Term Memory and Noise Bagging (NBG). The study employed Noise filters to enhance the performance of Decision Trees Bagging named NBG. Dataset utilized for this analysis were obtained from the website of Coin Market Cap, including: Binance Coin (BCN), BitCoin Cash (BCH), BitCoin (BTC), BitCoinSV (BSV), Cardano (CDO), Chainlink (CLK), CryptoCoin (CCN), EOS (EOS), Ethereum (ETH), LiteCoin (LTC), Monero (MNO), Stellar (SLR), Tether (TTR), Tezos (TZS), XRP (XRP), and daily data collected from exchange markets platforms spans from 2nd January 2018 to 7th July 2020. Auto encoder was utilized for the labelling of the trading strategies buy-hold-sell.
Beyhan Adanur Dedetürk, Ahmet Soran, Burcu Bakır-Güngör
The tremendous boost in the next generation sequencing technologies and in the "omics" technologies resulted in the generation of hundreds of gigabytes of data per day. Nowadays, via integrating -omics data with other data types, such as imaging and electronic health record (EHR) data, panomics studies attempt to identify novel and potentially actionable biomarkers for personalized medicine applications. In this respect, for the accurate analysis of -omics data and EHR, there is a need to establish secure and robust pipelines that take the ethical aspects into consideration, regulate privacy and ownership issues, and data sharing. These days, blockchain technology has picked up significant attention in diverse fields, including genomics, since it offers a new solution for these problems from a different perspective. Blockchain is an immutable transaction ledger, which offers secure and distributed system without a central authority. Within the system, each transaction can be expressed with cryptographically signed blocks, and the verification of transactions is performed by the users of the network. In this review, firstly, we aim to highlight the challenges of EHR and genomic data sharing. Secondly, we attempt to answer "Why" or "Why not" the blockchain technology is suitable for genomics and healthcare applications in detail. Thirdly, we elucidate the general blockchain structure based on the Ethereum, which is a more suitable technology for the genomic data sharing platforms. Fourthly, we review current blockchain-based EHR and genomic data sharing platforms, evaluate the advantages and disadvantages of these applications, and classify these applications using different metrics. Finally, we conclude by discussing the open issues and introducing our suggestion on the topic. In summary, to facilitate the diagnosis, monitoring and therapy of diseases with the effective analysis of -omics data with other available data types, through this review, we put forward the possible implications of the blockchain technology to life sciences and healthcare.
Recently, blockchain has been evolving rapidly with new innovations, coins, and use cases every day. The platform is getting more congested due to the increase of interest and mainstream adoption, and because most of this activity is on the widely used Ethereum blockchain. This also further increases the costs of using the platform, as the gas prices become higher. Smart contracts are deployed on the Ethereum blockchain and the high usage of these smart contracts is one of the main reasons behind the congestion. We propose a new scheme using sidechains and a middleware to reduce the workload for certain smart contracts, which allows the execution of smart contract transactions in parallel through sidechains. In this way, the sidechains could be leveraged to decrease the congestion on the main blockchain and increase the rate of transactions per second. Furthermore, the sidechains could have their settings, like block time and block gas limit, adjusted to give more optimal results. We implemented a modified version of the ballot contract from the solidity documentation, and our results demonstrated that through the use of two sidechains, the transactions processed per second could be increased from 1.8× to 13.0×, depending on the sidechains settings.
A key component of blockchain technology is the ledger, viz., a database that, unlike standard databases, keeps in memory the complete history of past transactions as in a notarial archive for the benefit of any future test. In second-generation blockchains such as Ethereum the ledger is coupled with smart contracts, which enable the automation of transactions associated with agreements between the parties of a financial or commercial nature. The coupling of smart contracts and ledgers provides the technological background for very innovative application areas, such as Decentralized Autonomous Organizations (DAOs), Initial Coin Offerings (ICOs) and Decentralized Finance (DeFi), which propelled blockchains beyond cryptocurrencies that were the only focus of first generation blockchains such as the Bitcoin. However, the currently used implementation of smart contracts as arbitrary programming constructs has made them susceptible to dangerous bugs that can be exploited maliciously and has moved their semantics away from that of legal contracts. We propose here to recompose the split and recover the reliability of databases by formalizing a notion of contract modelled as a finite-state automaton with well-defined computational characteristics derived from an encoding in terms of allocations of resources to actors, as an alternative to the approach based on programming. To complete the work, we use temporal logic as the basis for an abstract query language that is effectively suited to the historical nature of the information kept in the ledger.
Abstract We study the economic determinants of transaction fees in the Ethereum blockchain. We estimate an empirical model based on queueing theory and analyze the factors determining the “gas price” (transaction cost per unit of service, “gas”). Using block‐ and transaction‐level data from the Ethereum blockchain, we show that changes in service demand significantly affect the gas price—when there is high block utilization, per‐unit fees increase on average, with strong nonlinear effect above 90% utilization. The transaction type is another important factor—larger fraction of regular transactions (direct transfers between users) is associated with higher gas price.
An electronic toll collection (ETC) system is one of the most important parts of an intelligent transportation system (ITS), but existing ETC systems are not efficient and have vehicle fee evasion complications. Owing to the traceability and tamper resistance of a blockchain, the combination of a blockchain and ETC system is a feasible way to solve the above problems. However, traditional blockchain (e.g., Bitcoin and Ethereum) has high power consumption and low efficiency. Hence, it cannot be used in ETC systems with high throughput and is not suitable for power-constrained Internet of Things (IoT) devices. In this study, therefore, we propose a blockchain architecture for the ETC system. To curb vehicle fee evasion behavior, thereby reducing the economic loss caused, we propose a vehicle behavior management mechanism based on credit value. Furthermore, to reduce the burden of storage and build a chain of evidence for auditing purposes, we propose an evidence chain framework. To protect the data security in the transaction process, we designed a data protection method to encrypt the transaction data. Additionally, this system is based on an open-source alliance blockchain framework called Hyperledger Fabric, which is more in line with the current application scenarios of ETC systems. We implemented the system on a Raspberry Pi and carried out simulations. The comprehensive evaluation results and analysis show that the system effectively reduces the number of illegal acts, completes the evidence inspection, and improves the security of the data.
Nur Arifin Akbar, Andi Sunyoto, M. Rudyanto Arief, Wahyu Caesarendra
Today, there is a tendency to reduce the dependence on local computation in favor of cloud computing. However, this inadvertently increases the reliance upon distributed fault-tolerant systems. In a condition that forced to work together, these systems often need to reach an agreement on some state or task, and possibly even in the presence of some misbehaving Byzantine nodes. Although non-trivial, Byzantine Agreement (BA) protocols now exist that are resilient to these types of faults. However, there is still a risk for inconsistencies in the application state in practice, even if a BA protocol is used. A single transient fault may put a node into an illegal state, creating a need for new self-stabilizing BA protocols to recover from illegal states. As self-stabilization often comes with a cost, primarily in the form of communication overhead, a potential lowering of latency - the cost of each message - could significantly impact how fast the protocol behaves overall. Thereby, there is a need for new network protocols such as QUIC, which, among other things, aims to reduce latency. In this paper, we survey current state-of-the-art agreement protocols. Based on previous work, some researchers try to implement pseudocode like QUIC protocol for Ethereum blockchain to have a secure network, resulting in slightly slower performance than the IP-based blockchain. We focus on consensus in the context of blockchain as it has prompted the development and usage of new open-source BA solutions that are related to proof of stake. We also discuss extensions to some of these protocols, specifically the possibility of achieving self-stabilization and the potential integration of the QUIC protocol, such as PoS and PBFT. Finally, further challenges faced in the field and how they might be overcome are discussed.
Access control is a main component in Blockchain systems. It is usually implemented in smart contracts and defines the security policy, in other words, it determines who can access a protected resource in the network. In this paper, we present a review of the major implementations of access control in Ethereum platform. The latter is based on RBAC model (Role-Based Access Control). Implementations require to take into account the whole RBAC process, that is, user role assignment and permission assignment. Three implementations currently exist and are described and compared in this work according to several features: RBAC-SC, Smart policies and OpenZepplin contracts.
Ballots are often hold for fair decisions such as party theme selecting, however, the existing traditional ballot has some problems involving amount of human resources, cost of places, equipment, time and traffic, and repeated procedures. In order to solve the issues aforementioned, a ballot blockchain system is designed and implemented based on the smart contract of Ethereum. It is designed on the core blockchain technologies of the decentralized ledger technology, using a secure hash algorithm, anonymous user, incorruptible data, and adopting a public blockchain. The ballot blockchain system is implemented based on the MetaMask verification and the Remix interface development environment. The smart contract plays the role of the decision-maker for controlling ballot activities instead of numerous human tasks. All ballot transactions are recorded in the ballot blockchain permanently when the ballot completed. The aim of the ballot blockchain system is to achieve a fair, less time-consuming, secured, and transparent environment.
Riri Fitri Sari, Asri Samsiar Ilmananda, Daniela M. Romano
In the current digital era, information exchanges can be done easily through the Internet and social media. However, the actual truth of the news on social media platforms is hard to prove, and social media platforms are susceptible to the spreading of hoaxes. As a remedy, Blockchain technology can be used to ensure the reliability of shared information and can create a trusted communications environment. In this study, we propose a social media news spreading model by adapting an epidemic methodology and a scale-free network. A Blockchain-based news verification system is implemented to identify the credibility of the news and its sources. The effectiveness of the model is investigated by utilizing agent-based modelling using NetLogo software. In the simulations, fake news with a truth level of 20% are assigned a low News Credibility Indicator (NCI ± -0.637) value for all of the different network dimensions. Moreover, the Producer Reputation Credit is also decreased (PRC ± 0.213) so that the trust factor value is reduced. Our epidemic approach for news verification has also been implemented using Ethereum Smart Contract and several tools such as React with Solidity, IPFS, Web3.js, and Metamask. By showing the measurements of the credibility indicator and reputation credit to the user during the news dissemination process, this proposed smart contract can effectively limit user behaviour in spreading fake news and improve the content quality on social media.
Alan Rodrigues, Allysson Allex Araújo, Matheus Paixão, Pamella Soares
Blockchain tem sido enquadrada como uma nova infra-estrutura disruptiva baseada na internet. Parcela desse potencial advém do fortalecimento de plataformas públicas de blockchain, como a Ethereum, as quais viabilizam Aplicações Descentralizadas (dApps). Tais soluções são baseadas em contratos inteligentes (CIs) e lidam com restrições específicas que desafiam a evolução de software, como a imutabilidade de dados e o acesso transparente ao código-fonte. Em particular, a transparência de código pode ser observada através de ferramentas como o Etherscan, a qual provê acesso público a uma vasta quantidade de informações sobre os CIs implantados na Ethereum. Além disso, pode-se observar organizações oriundas desse ecossistema aderindo à prática de desenvolvimento open source dos CIs, incluindo o amplo uso do GitHub. Esse rico cenário motivou a necessidade de conduzir um estudo exploratório-descritivo baseado em mineração de repositórios de software para compreender a evolução de software de CIs através da avaliação de similaridade entre a versão disponível no GitHub e versão utilizada na Ethereum (e auditável via Etherscan). À luz de uma análise quali-quantititativa de 27 CIs, este artigo contribui ao 1) caracterizar quatro padrões que denotam diferentes comportamentos evolutivos dos CIs e 2) abordar um método experimental baseado em string para comparar a similaridade entre diferentes versões de CIs.
We design a Multi-Layer Aggregate Verification (MLAV) solution to improve supply chain management with IoT Blockchain devices. We apply MLAV to IoT Blockchain applications in Agriculture 4.0 to demonstrate the feasibility of our solutions and models. In the current Agriculture 4.0 structure, large companies have successfully applied blockchain solutions and ecosystems for tracking and tracing agricultural produce, achieving transparency, traceability, and digitalization. However, these existing blockchain solutions are not comprehensive. First, the upstream nodes they serve are all large-scale production suppliers, and smallholders are not taken into consideration. In order to solve this problem, we use a multi-layer architecture that serves three purposes: facilitating smallholders in joining the agricultural blockchain as equal-opportunity nodes, uploading of production activity data, and reducing costs (ex. Ethereum gas fee). Second, the majority of IoT blockchains adopt an ID-based signature scheme in IoT devices, which frequently has lower efficiency. In applying aggregate verification, we may effectively increase ID-based verification efficiency while processing large clusters of data transferred by IoT devices. Finally, we design a blockchain management framework using smart contracts to facilitate the financing of upstream producers.
Sebastian Friebe, Oliver Stengele, Hannes Hartenstein, Martina Zitterbart
When software systems become more complex, it can be advantageous to partition their code into multiple, separate components. In this work, we examine how multiple smart contracts can be coupled to work together. When coupling smart contracts, different design approaches are possible with their own advantages and disadvantages. As an example, we couple two smart contract applications on the Ethereum blockchain: Palinodia and DecentID. Palinodia can be used to ensure the integrity of downloaded executable binaries by checking their hashes against the hashes stored in the blockchain. To make sure that not everyone can modify the data stored on the blockchain, an identity management system is required. This task is fulfilled by DecentID, which provides decentralized identities stored as smart contracts on the blockchain. We evaluate approaches of coupling these two applications and discuss their benefits and drawbacks for this use case.
Paulo Valente Klaine, Lei Zhang, Muhammad Ali Imran
Nowadays data is one of the most important assets that can be obtained, as many applications rely on data to generate useful services. However, a very few number of companies control, in a centralized manner, a large portion of data. That, combined with inefficiencies in centralized storage and recent data leak scandals, highlights the need for new ways in which data is shared and consumed, in which privacy and access control is guaranteed by design. Based on that, in this paper we present an implementation of a blockchain-based data marketplace utilizing the Go Ethereum (Geth) library. The implementation consists of an IoT node powered by a raspberry pi zero W, which is utilized to collect data from the environment and store it in an InterPlanetary File System (IPFS) external server, a web page that displays the marketplace, and a private blockchain that records transactions. Regarding the private blockchain, three smart contracts are developed in order to: 1) record information about the data in the marketplace; 2) record transactions that occur between users; 3) allow sellers to white/blacklist buyers' access to the data. This implementation shows that a decentralized blockchain-based marketplace is feasible and scalable, and we hope it can serve as an early model for future frameworks.
The use of Artificial Intelligence (AI), in particular sequential decision-making (SDM) algorithms, in blockchains can greatly improve their autonomy and general features. In this context, this paper proposes the protocol CONDOR (Connecting ai-based Oracles to blockchaiN via an auDitable auctiOn pRotocol) between a smart contract and some off-chain AI-based oracles to enable the smart contract to choose among AI solution proposals while inciting those oracles to provide non-forged results. The main principle is to consider the AI outcomes as auctions that can be challenged and audited through a dispute phase. An Ethereum implementation of the aforementioned protocol was built in order to assess its scalability and time performances.