In the changing circumstances and the conflict between Russia and Ukraine, International crude oil prices rose sharply in the short term. This study will review the existing literature on the reason for the fluctuation of international crude oil prices and the dynamic change of Bitcoin, Tether, and Ethereum. This paper will also empirically evaluate the impact of fluctuation of international crude oil prices on the yield of electronic cryptocurrency. This research finds that the increase of futures crude oil prices will have a positive impact on the yield of electronic cryptocurrency, but this impact is short-term. Additionally, the growth of crude oil prices will not lead to the increase in the daily volatility of electronic cryptocurrency.
A food shortage, which has increased with the climate crisis, will be one of the biggest problems of the world, together with water scarcity, in the future and will damage the sustainability of the food supply system. With the effect of the COVID-19 pandemic, food resources are decreasing, and food prices are rising all over the world. The decrease in food sources increases the importance of food tracking even more. The exorbitant price increases after the COVID-19 pandemic are the most concrete indicators of this. Blockchain-based food tracking systems will be of critical importance because they will prevent exorbitant price increases with their contribution to food tracking processes, such as reliability and transparency. In this study, the establishment of a blockchain-based food tracking system in Turkey, its operation, and its results will be discussed. It was concluded that 97.54% of the participants using the established system found the application useful and wanted such an application to become widespread. In addition, comparing the performance data of the established blockchain-based system with other blockchain infrastructures, a value of 0.038 s for latency is 435 times better than Ethereum, one of the most popular blockchain infrastructures. A transmission per second value of 285, reception per second value of 335, and CPU load rate value of 19.22 are obtained with the proposed system.
The emergence of metaverse brings tremendous evolution to Non-Fungible Tokens (NFTs), which could certify the ownership the unique digital asset in the cyber world. The NFT market has garnered unprecedented attention from investors and created billions of dollars in transaction volume. Meanwhile, securing NFT is still a challenging issue. Recently, numerous incidents of NFT theft have been reported, leading to incalculable losses for holders. We propose a decentralized NFT anti-theft mechanism called TokenPatronus, which supports the general ERC-721 standard and provide the holders with strong property protection. TokenPatronus contains pre-event protection, in-event interruption, and post-event replevin enhancements for the complete NFTs transactions stages. Four modules are designed to make up the decentralized anti-theft mechanism, including the decentralized access control (DAC), the decentralized risk management (DRM), the decentralized arbitration system (DAS) and the ERC-721G standard smart contract. TokenPatronus is performing on the Turtlecase NFT project of Ethereum and will support more blockchains in the future.
Mirko Zichichi, Stefano Ferretti, Gabriele DâAngelo, Victor RodrıÌguez-Doncel
Abstract The centralization of control over the processing of personal data threatens the privacy of individuals due to the lack of transparency and the obstruction of easy access to their data. Individuals need the tools to effectively exercise their rights, enshrined in regulations such as the European Union General Data Protection Regulation (GDPR). Having direct control over the flow of their personal data would not only favor their privacy but also a âdata altruismâ, as supported by the new European proposal for a Data Governance Act. In this work, we propose a multi-layered architecture for the management of personal information based on the use of distributed ledger technologies (DLTs). After an in-depth analysis of the tensions between the GDPR and DLTs, we propose the following components: (1) a personal data storage based on a (possibly decentralized) file storage (DFS) to guarantee data sovereignty to individuals, confidentiality and data portability; (2) a DLT-based authorization system to control access to data through two distributed mechanisms, i.e. secret sharing (SS) and threshold proxy re-encryption (TPRE); (3) an audit system based on a second DLT. Furthermore, we provide a prototype implementation built upon an Ethereum private blockchain, InterPlanetary File System (IPFS) and Sia and we evaluate its performance in terms of response time.
The art world is slow to adapt to new technology. Back in 2019, which seems like eons ago in Internet time, the Hiscox online art trade report noted that the online art market grew 9.8% in aggregate in 2018 to $4.64 billion, a slowdown from the growth experienced in the previous three years. More telling, the same report notes that the âart worldâs adoption of blockchain technology remains slow as convincing [use cases] fail to materialise.â Of course, there are structural reasons and specific factors that make the art world unique in its steadfast commitment to âtraditionalâ transactional formats, including the benefits reaped from in-person inspection of unique works executed in a physical medium, as well as the privacy and competitive benefits afforded by relative market opacity.
 Like it or not, the art world is being forced to reckon with the metaverse. During the COVID-19 pandemic, homebound collectors helped to buoy the online art market. Online sales in 2020 accounted for â15.8% of all art sales, up from 7.5% in 2019,â with âsales in the first half of 2021 . . . up by 72% to $6.8 billion.â Sales of non-fungible tokens (NFTs) reached around $3.5 billion in the first three quarters of 2021. Although not a person, ERC-721, which sets forth a standard specification for tokens on the Ethereum-based blockchain, topped ArtReviewâs annual âPower 100â list of the most influential people in the contemporary art world in 2021.
 Specifically with respect to NFTs, art-world stakeholders appear to be of two camps: some curious and diving in, and others feeling skeptical. What is it about NFTs that make certain art-world stakeholders wish they were a passing fad? What is the legal landscape for this fast-growing portion of the metaverse? And how can artists and purchasers protect themselves using pre-existing legal concepts and frameworks? These are some of the questions that we discuss in this Article. After covering what NFTs are and the application of the pre-existing U.S. copyright framework to the NFT format, we elucidate some considerations and issues that artists face when they decide to mint their work and sell NFTs. We also address some concerns that purchasers of NFTs may have. Because the environment is fast-paced and a single set of standards or guidelines has not yet been adopted, we discuss certain types of terms and conditions that currently govern the sale and use of NFTs. In sharing recent case studies, contracts, and projects we have worked on, we hope to provide a snapshotâif fleetingâof the current dynamic world of NFTs.
G. Yedukondalu, Channapragada Rama Seshagiri Rao, Raman Dugyala
Industrial Internet of Things (IIoT) is changing many driving enterprises like transportation, mining, horticulture, energy and medical care. Machine Learning calculations are utilized for getting stages for IT frameworks. The IoT network unit hubs typically asset in a strange manner by making them more responsible to digital assaults. IIoT frameworks requests various situations in genuine one among them is giving security and the causes that encompass them in true viewpoints. It incorporates a system called PriModChain causes security and reliability on IIoT information by joining differential protection, Ethereum block chain and unified Machine learning. Consequently, security will be compromised and we use PriMod chain for giving protection and different compliances and created utilizing Python with attachment programming on essential PC.
Along with the advancements in blockchain technology, many blockchain-based successful projects have been done mainly on the ethereum platform, most of which deal with transactions.Still, it also carries various risks when it comes to security, as evident from past attacks.Most big projects like uniswap, decentraland, and others use smart contracts, deployed on the ethereum platform, leading to similar projects via code reuse.Code reuse practice is quite frequent as a survey suggests 26% of contract code deployed is via code reuse.Smart contract code obfuscation techniques can be used on solidity code that is publicly verified, published (in the case of Ethereum), and on the deployment address.All the above techniques work by replacing characters with their random counterpart, known as statistical substitution.A statistical substitution is a process of transforming an input string into a new string where each character has been replaced by a random character drawn from a stock of all possible 'random' characters.Therefore, we proposed numerous methods in this paper to solve the above problems using various smart contract code obfuscation techniques.These techniques can be really useful in blockchain projects and can save millions of dollars to investors & companies by enhancing code security and preventing code reusability.Techniques mentioned in this paper when compared with other techniques.Our methods are not expensive to implement, very easy to use, and provide a developer-friendly selective increment in code complexity.
With the success of Bitcoin and the introduction of different uses of Blockchain, such as smart contracts in Ethereum, many researchers and industries have turned their attention to applications that use this technology. In response to the advantages and disadvantages of Blockchain, similar technologies have emerged with alterations to the original structure. Distributed ledger technology (DLT) is a generalized distributed technology encompassing these new variants. Several studies have examined the challenges and applications of Blockchain technology. This article explores the possibilities of using different DLTs to solve traditional distributed computing problems based on their advantages and disadvantages. In this paper, we provide an overview and comparison of different DLTs, such as Hashgraph, Tangle, Blockchains, Side Chain and Holochain. The main objective of the article is to examine whether distributed ledger technologies can replace traditional computational methods in other areas instead of traditional methods. Based on the primary keywords, we conducted a systematic review of more than 200 articles. Based on the data extracted from articles related to the use of DLT, we conclude that that DLTs can complement other methods, but cannot completely replace them. Furthermore, several DLTs such as Sidechain, Holochain and Hashgraph are still in their infancy, and we foresee much research work in this area in the coming years.
The cryptocurrency market offers significant investment opportunities but also entails higher risks as compared to other asset classes. This article aims to analyse the financial risk characteristics of individual cryptocurrencies and of a broad cryptocurrency market portfolio. We construct a portfolio comprising the 20 largest cryptocurrencies, which cover 82.1% of the total cryptocurrency market. The returns are examined for extreme tail risks by the application of Extreme Value Theory. We utilise the GARCH-EVT approach in combination with a novel algorithm to automatically determine the optimal threshold to model the tail distribution. Furthermore, we aggregate the individual market risks with a t-Student Copula to investigate possible diversification effects on a portfolio level. The empirical analysis indicates that all examined cryptocurrencies show high volatility in their price movements, whereby Bitcoin acts as the most stable cryptocurrency. All return distributions are heavy-tailed and subject to extreme tail risks. We find strong, positive intra-market correlations, in particular with the two largest cryptocurrencies Bitcoin and Ethereum. No diversification effect can be achieved by aggregating market risks. On the contrary, a negligibly lower expected return and higher joint extreme returns can be observed. From this analysis, it can be concluded that investments in individual cryptocurrencies as well as in a portfolio show extreme risks of losses. From the investorâs point of view, a possible strategy of risk reduction through portfolio formation within cryptocurrencies is only promising to a limited extent and does not offer a satisfactory solution to significantly reduce the risk within this asset class.
RENATO MOTA RUIZ, INACIO HENRIQUE YANO, Alexandre de Castro, Julio Cezar Souza Vasconcelos
This work aims to evaluate the storing and retrieving data response time using an Ethereum Smart Contract application to verify the feasibility of its utilization instead of using relational databases in web application development. To achieve the objectives of this work. There was a comparison between the Ethereum Smart Contract and the SQLite, considering response time as the user experience for database choice decisions in future application development. This study consisted of the development of two similar applications. The first one was the Ethereum Smart Contract Application, and the other was the SQLite Application. Using these applications to build graphs of response time behavior as the number of records processed grows. For storing data Blockchain application was much faster than the SQLite application. When retrieving data, the Blockchain application usually starts slower but finishes faster than the SQLite application. Blockchain is a recent technology for secure data storage in a distributed architecture. The hypothesis to be checked was if it also has a good response time compared with other databases. The contribution of this work is to provide information about the efficiency and possible user satisfaction of Blockchain applications.
Open access
Neural Networks and Applications
Advanced Computational Techniques and Applications
Ethereum Trader demo buying and selling function is a duplicate of the stay buying and selling platform for cryptocurrencies. However, it's far mentioned that most effective registered customers can check the demo buying and selling function. The demo dealer gives the identical enjoy while as compared to stay buying and selling. However, Ethereum Trader the customers who check the demo dealer will now no longer use actual cash to alternate cryptocurrencies. The concept at the back of demo buying and selling is to permit capability traders to check the gadget and notice how a great deal they are able to earn after a buying and selling consultation ends.
Recently, Decentralized Finance (DeFi) platforms on Ethereum are booming, and numerous traders are trying to capitalize on the opportunity for maximizing their benefits by launching front-running attacks and extracting Miner Extractable Values (MEVs) based on information in the public mempool. To protect end users from being harmed and hide transactions from the mempool, private transactions, a special type of transactions that are sent directly to miners, were invented. Private transactions have a high probability of being packed to the front positions of a block and being added to the blockchain by the target miner, without going through the public mempool, thus reducing the risk of being attacked by malicious entities. Despite the good intention of inventing private transactions, due to their stealthy nature, private transactions have also been used by attackers to launch attacks, which has a negative impact on the Ethereum ecosystem. However, existing works only touch upon private transactions as by-products when studying MEV, while a systematic study on private transactions is still missing. To fill this gap and paint a complete picture of private transactions, we take the first step towards investigating the private transactions on Ethereum. In particular, we collect large-scale private transaction datasets and perform analysis on their characteristics, transaction costs and miner profits, as well as security impacts. This work provides deep insights on different aspects of private transactions.
The term blockchain is mainly regarded as the distributed transaction which is mainly comprised of different blocks, and each set tends to represent the data that are being associated with the previous blocks. The blockchain is mainly managed through peer-to-peer networks which comparatively involves in adhering to the protocol of authenticating various blocks to form the blockchain. The usage of blockchain technology has been increasingly used in different fields, and healthcare services are now using blockchain for better patient delivery, detecting disease, and other aspects. The scope of the proposed study is that this study has exploited the function of a blockchain-enabled big data network to support medical professionals in giving better treatment modalities and delivering better patient care. The application of a new generation of smart block chains such as Ethereum and NEM is now offering better services and features in creating blockchain-based healthcare data management and hence support healthcare centers, medical practitioners, nurses, radiologists, and patients for better healthcare management. The application of blockchain technology in big data networks supports adding more value as it results in enhanced data quality, accessibility, and support in creating better security and safety of data and information, which is highly essential in the medical industry. Blockchain technology enables big data technologies enabled in supporting medical practitioners in addressing various healthcare ailments; one of the major diseases impacting many people around the world is diabetes. Patients with such ailments tend to generate more data and information related to the disease and health-related aspects. Hence, this information requires being maintained and analyzed, so that superior healthcare services can be provided. This study is more involved in the investigation of blockchain technology through a big data network enabled in offering better care for elderly individuals who have been affected due to diabetes, the researchers propose to choose a questionnaire method to collect the data from nearly 169 respondents, and these data were then analyzed using SPSS data package. The analyst used percentage analysis, correlation analysis, and chi-square test to analyze the data which has been collated by the researchers. The results and discussion show in detail the major aspects of blockchain technology in supporting healthcare professionals for better diabetes care management for elderly individuals.
Open-source software has made a breakthrough in the traditional intellectual property theory from the aspects of Copyright, patent right, and trademark right, and it has created a new property rights form in the form of license. Taking blockchain as an example, this paper analyzes bitcoin and Ethereum and their open-source licensing strategies. At the same time, it explores the problems encountered in the property rights of open-source blockchain and three possible solutions to this dilemma: The industry-standard licensing plan, blockchain open-source licensing scheme, and open patent scheme. This research will be significant for expanding and enriching the theoretical and practical analysis of blockchain open source in the field of intellectual property.
Sumit Kumar Rana, Sanjeev Rana, Kashif Nisar, Ag Asri Ag Ibrahim · 7 authors
Healthcare, one of the most important industries, is data-oriented, but most of the research in this industry focuses on incorporating the internet of things (IoT) or connecting medical equipment. Very few researchers are looking at the data generated in the healthcare industry. Data are very important tools in this competitive world, as they can be integrated with artificial intelligence (AI) to promote sustainability. Healthcare data include the health records of patients, drug-related data, clinical trials data, data from various medical equipment, etc. Most of the data management processes are manual, time-consuming, and error-prone. Even then, different healthcare industries do not trust each other to share and collaborate on data. Distributed ledger technology is being used for innovations in different sectors including healthcare. This technology can be incorporated to maintain and exchange data between different healthcare organizations, such as hospitals, insurance companies, laboratories, pharmacies, etc. Various attributes of this technology, such as its immutability, transparency, provenance etc., can bring trust and security to the domain of the healthcare sector. In this paper, a decentralized access control model is proposed to enable the secure interoperability of different healthcare organizations. This model uses the Ethereum blockchain for its implementation. This model interfaces patients, doctors, chemists, and insurance companies, empowering the consistent and secure exchange of data. The major concerns are maintaining a history of the transactions and avoiding unauthorized updates in health records. Any transaction that changes the state of the data is reflected in the distributed ledger and can be easily traced with this model. Only authorized entities can access their respective data. Even the administrator will not be able to modify any medical records.
Smart contract represents an essential application scenario of blockchain technology.Smart contract technology improves programmability and scalability of blockchain, and has broad development prospects.However, a series of security incidents caused a great number of economic losses and weakened usersâ confidence in the Ethereum platform.The security of smart contract has become a critical problem that restricts the further development of smart contract.Defects in smart contract code may cause serious consequences and cannot be modified once deployed, it is especially important to verify the correctness of smart contract in advance.In recent years, researchers have obtained many achievements in verification of smart contract, but there is a lack of systematic summary of these research results.Therefore, some basic principles of Ethereum were introduced, including the transaction, gas mechanism, storage and programming language.Eight common types of vulnerabilities in smart contract were summarized and their causes were explained.Some real security events were reviewed and some examples of vulnerability codes were presented.Then, the research work on automatic verification of smart contract based on symbolic execution, model checking and theorem proving was classified and summarized.Three open-source automated tools were selected, including Mythril, Slither and Oyente.And experiments were implemented to evaluate and compare the three tools from the aspects of efficiency, accuracy and the types of vulnerability can be detected.Furthermore, related review articles were surveyed, and the advantages of this paper compared with these works were summarized.The critical problems in the vulnerability detection technology of smart contract were also summarized and the direction of future research was proposed at last.
The article proposes UML diagrams of the property right distribution module using NFT fractalization based on blockchain technology, which allow to develop software for the implementation of the modern way of fractions generation according to the ERC-1155 standard. A blockchain is a distributed database that is shared among the nodes of a computer network. As a database, a blockchain stores information electronically in digital format. Blockchains are best known for their crucial role in cryptocurrency systems, such as Bitcoin, for maintaining a secure and decentralized record of transactions. The innovation with a blockchain is that it guarantees the fidelity and security of a record of data and generates trust without the need for a trusted third party. This standard was chosen for the impossibility of offering fractions for sale on other platforms, ensuring the uniqueness of the proposed decentralized application. The main reason for the development is to create a module located on the network blockchain, ensuring the security of functionality with cryptographic algorithms from one of the most secure blockchain â Ethereum. The task of development is to implement functionality that ensures the fulfillment of all functional requirements, the most important of which are the creation of a unique NFT to the userâs property, its Fractionalization and the sale of fractions to other users.
Open access
Economic and Technological Systems Analysis
Advanced Research in Systems and Signal Processing
Energy consumption of consensus mechanisms used in permissionless distributed ledger, such as Bitcoin and Ethereum, has become a popular research topic. Computation and storage operations combined with proof of work (PoW) to prevent attacks requires a lot of energy consumption. Due to the permissionless nature of blockchain, it is difficult to measure the energy consumed by each node. Therefore, estimation methods provide approximations such as lower and upper bounds on energy consumption. A recent work in this direction has shown that PoW is the most energy consuming consensus. In this context, there is a timely requirement to find solutions to optimize the energy consumption. Our proposal aims at building a typical consensus in distributed ledger with an asynchronous protocol to reduce wasted computations involved in the proof of work. For this purpose, we rely on a similarity search index to prevent double-spending attacks and reduce the difficulty mining involved in the PoW, by exploring how it influences the number of required iterations needed to solve the PoW.
Abstract Developments in digital technologies are considered to be the most important innovations since the advent of the internet. In several countries, this has led to a significant change in the way payments are made, leading to new forms of payment, such as crypto-currencies. With regard to cryptocurrencies, it remains a complex issue involving especially volatility, but also money laundering and consumer protection issues. While most countries consider cryptocurrencies too volatile to be used as a payment alternative, crypto-currencies gain interest of investors in the last 10 years due to the possibility of obtaining large profits. The aim of the paper is to study the volatility of the first 5 cryptocurrencies (Bitcoin, Ethereum, Binance Coin, Cardano and Ripple) through GARCH models. The process of evaluating highly volatile cryptocurrencies is complex and depends on many parameters. Therefore, our results would be particularly useful in terms of portfolio and risk management and could help them to be more agile in evaluating their investments, in making optimal decisions and making future forecasts. We find that the GARCH (1.1) models provide the best fit, in terms of modelling of the volatility in the most popular and largest cryptocurrencies. The results show that for BTC, ETH and XRP the appropriate model is GARCH (1.1) and in the case of BNC and CARDANO GARCH-M explain better the volatility of the crypto-currencies. Therefore, more in depth analysis of the datasets may be required to confirm or deny possible structural change. The study can be complemented by carrying out an event study on the 5 cryptocurrencies analyzed or extending the analysis by applying other GARCH models, to research the optimal model for several cryptocurrencies.
Nor Ashbahani Mohamad Kajaan, Nurul Hanisa Nor Amidi, Zainal Salam, Raja Zahilah Raja Mohd Radzi
Abstract The purpose of this study is to propose a method of peer-to-peer (P2P) energy trading that allow prosumers with energy deficiency to buy energy from prosumers with excess energy in a microgrid system. The proposed method solves the problems associated with lack of trust in P2P energy trading and utilized the blockchain technology that made it impossible to tamper with data. The data is referred as transaction generated by using blockchain. A blockchain based smart contract execute the trading and payment rules without the intermediaries. Thus, the security and fairness of energy trading are significantly enhanced compared to conventional database technology. Without the third-party intervention, a miner that is selected among the participants in the microgrid environment process all the transaction generated from buying and selling energy. The smart contract consists of two main components; bidding and settlement module, payment module. The smart contract deployed in blockchain test network to test the interaction of smart contract. From the simulation, the proposed method is validated using realistic data with the Ethereum Virtual Machine (EVM). The method will be expected to be useful to designers who need to integrate renewable energy in a microgrid system.
Teknologi blockchain telah digunakan secara luas dan menarik perhatian para peneliti termasuk peneliti tanaman hortikutur. Cabai merupakan salah satu tanaman hortikultura yang banyak dibudidayakan di Indonesia dan merupakan salah satu komoditas yang memiliki harga yang sangat fluktuatif. Fluktuasi harga cabai menuntut adanya transparansi harga cabai di setiap rantai distribusi cabai. Studi ini bertujuan untuk mengembangkan sistem pencatatan transaksi distribusi cabai dalam upaya mencatat semua transaksi produksi dan harga cabai di setiap rantai distribusi cabai. Sistem ini berbasis web dan dikembangkan dengan menggunakan teknologi blockchain untuk menyimpan setiap transaksi distribusi cabai. Pengembangan sistem menggunakan metode extreme programming yang dilakukan dalam dua iterasi. Pada studi ini, smart contract Ethereum menggunakan kerangka kerja Truffle untuk sistem back end dan web3js untuk antarmuka sistem. Sistem pencatatan transaksi distribusi cabai telah berhasil dikembangkan dan memungkinkan pengguna untuk melihat harga dan pasokan cabai secara transparan di setiap rantai distribusi cabai. Uji keberterimaan dan fungsionalitas sistem telah sukses dilakukan untuk para aktor distribusi cabai, yaitu admin, produsen, pedagang pengepul, grosir, pedagang pengecer, serta konsumen. Smart contract yang dihasilkan dirilis pada jaringan uji Ethereum serta jaringan uji Rinkeby sebagai pengganti jaringan utama Ethereum. Sistem pencatatan cabai masih dapat dikembangkan lebih lanjut untuk melengkapi berbagai fitur yang telah dibuat. Rekomendasi untuk studi lebih lanjut dapat dilakukan untuk pengembangan fitur tambahan seperti foto produksi cabai dan foto profil aktor distribusi cabai serta user experience para aktor rantai distribusi cabai.
Blockchains are meant to be persistent: posted transactions are immutable and cannot be changed. When a theft takes place, there are limited options for reversing the disputed transaction, and this has led to significant losses in the blockchain ecosystem. In this paper we propose reversible versions of ERC-20 and ERC-721, the most widely used token standards. With these new standards, a transaction is eligible for reversal for a short period of time after it has been posted on chain. After the dispute period has elapsed, the transaction can no longer be reversed. Within the short dispute period, a sender can request to reverse a transaction by convincing a decentralized set of judges to first freeze the disputed assets, and then later convincing them to reverse the transaction. Supporting reversibility in the context of ERC-20 and ERC-721 raises many interesting technical challenges. This paper explores these challenges and proposes a design for our ERC-20R and ERC-721R standards, the reversible versions of ERC-20 and ERC-721. We also provide a prototype implementation. Our goal is to initiate a deeper conversation about reversibility in the hope of reducing some of the losses in the blockchain ecosystem.
Due ecosystem, it is common for new blockchains to fork or partially reuse the code of classic blockchains. For example, the popular Dogecoin, Litecoin, Binance BSC, and Polygon are all variants of Bitcoin/Ethereum. These âforkedâ blockchains thus could encounter similar vulnerabilities that are propagated from Bitcoin/Ethereum during forking or subsequently commit fetching. In this paper, we conduct a systematic study of detecting and investigating the propagated vulnerabilities in forked blockchain projects. To facilitate this study, we propose BlockScope, a novel tool that can effectively and efficiently detect multiple types of cloned vulnerabilities given an input of existing Bitcoin/Ethereum security patches. Specifically, BlockScope adopts similarity-based code match and designs a new way of calculating code similarity to cover all the syntax-wide variant (i.e., Type-1, Type-2, and Type-3) clones. Moreover, BlockScope automatically extracts and leverages the contexts of patch code to narrow down the search scope and locate only potentially relevant code for comparison. Our evaluation shows that BlockScope achieves good precision and high recall both at 91.8% (1.8 times higher recall than that in the state-of-the-art ReDeBug while with close precision). BlockScope allows us to discover 101 previously unknown vulnerabilities in 13 out of the 16 forked projects of Bitcoin and Ethereum, including 16 from Dogecoin, 6 from Litecoin, 1 from Binance BSC, and 4 from Optimism. We have reported all the vulnerabilities to their developers; 40 of them have been patched or accepted, 66 were acknowledged or under pending, and only 4 were rejected. We further investigate the propagation and patching processes of discovered vulnerabilities, and reveal three types of vulnerability propagation from source to forked projects, as well as the long delay (mostly over 200 days) for releasing patches in Bitcoin forks (vs. âŒ100 days for Ethereum forks).
Francesco Maria De Collibus, Matija PiĆĄkorec, Alberto Partida, Claudio J. Tessone
In this paper, we use the methods of networks science to analyse the transaction networks of tokens running on the Ethereum blockchain. We start with a deep dive on four of them: Ampleforth (AMP), Basic Attention Token (BAT), Dai (DAI) and Uniswap (UNI). We study two types of blockchain addresses, smart contracts (SC), which run code, and externally owned accounts (EOA), run by human users, or off-chain code, with the corresponding private keys. We use preferential attachment and network dismantling strategies to evaluate their importance for the network structure. Subsequently, we expand our view to all ERC-20 tokens issued on the Ethereum network. We first study multilayered networks composed of Ether (ETH) and individual tokens using a dismantling approach to assess how the deconstruction starting from one network affects the other. Finally, we analyse the Ether network and Ethereum-based token networks to find similarities between sets of high-degree nodes. For this purpose, we use both the traditional Jaccard Index and a new metric that we introduce, the Ordered Jaccard Index (OJI), which considers the order of the elements in the two sets that are compared. Our findings suggest that smart contracts and exchange-related addresses play a structural role in transaction networks both in DeFi and Ethereum. The presence in the network of nodes associated to addresses of smart contracts and exchanges is positively correlated with the success of the token network measured in terms of network size and market capitalisation. These nodes play a fundamental role in the centralisation of the supposedly decentralised finance (DeFi) ecosystem: without them, their networks would quickly collapse.