Santeri Paavolainen, Christopher Carr, Essam Ghadafi
The Ethereum blockchain is one of the most popular permissionless blockchains. A consequence of its popularity has been the growth of processing and data storage requirements for any node participating in the Ethereum blockchain network. For constrained devices such requirements are often infeasible to meet. To cater for such nodes, a so-called light protocol has been proposed for Ethereum where the responsibility of maintaining a correct state representation is delegated to light protocol servers. Previous research has identified dependence on external state management as a potential security vulnerability that exclusively impacts light nodes. Although a simple mitigation strategy is available, it comes at the expense of increased latency. In this work, we propose a new Ethereum node type, which we call a subset node, as an extension of the light protocol. Our proposal allows subset nodes to gain a lower latency than a pure light node with comparable or even higher security assurances by tracking and evaluating only a subset of all of the transactions issued on the blockchain. We provide a formal proof on the correctness of the blockchain state used by the subset node under the proposed model. To evaluate the practical feasibility of the subset node model, we analyze one year of historical transaction data from Ethereum, and demonstrate that a subset node tracking the state of a single account can achieve a significant reduction in storage and computational requirements when compared to a full node.
Abstract In recent years, performance management has become more and more significant in terms of management and credibility of universities. They have to review student performance when issuing diplomas. Therefore, the reliability of student performance management is extremely important. Nowadays, many universities adopt a data-centralized management model. However, centralized database often brings about problems such as information leakage and easy tampering. With the development of blockchain technology, its decentralized and unforgeability characteristics have gradually attracted people’s attention. In order to prevent students’ scores from being maliciously tampered with, we utilize blockchain to design and implement a decentralized student score sharing management system. Moreover, by using the Ethereum smart contract to manage on-chain and off-chain data storage as well as on-chain query and verification, we ensure the traceability, tamper-proof, distributed storage, and the security of query process. Finally, this article explores the construction of prototype system based on the Ethereum environment. The experimental results show that the anti-tampering and traceability scheme proposed in this article is feasible. The application of blockchain can fully satisfy the needs of various participants in student performance management. Each subject’s information has a separate decryption private key, which perfectly protects student’s score information.
Cryptocurrency has been one of the tools that originated from the blockchain technology used in the financial world and have been a topic of debate among several diasporas concerned with the financial and money markets. It is known that cryptocurrencies such as Bitcoin, Ethereum etc., are in demand and used for transactions securing the financial purposes that illustrate the need and utility of such cryptocurrencies. Cryptocurrencies are a product of insecurity and instability in the financial markets; however, the measurement of the pricing of cryptocurrency itself is based on the perception of people, which makes it highly volatile and disadvantageous in many ways. It's also evidence that there are many threats and challenges that these cryptocurrencies present that come from using them for crime, terrorism, and money laundering, among others. This calls for a significant change in the cryptoasset market, which has the potential to claim a greater stake in the financial market in the coming years. Relevance and utility of the cryptocurrency cannot be neglected because of its misappropriation; instead, regulations must be made to minimize such negative actions with the positive utility of such cryptocurrency. The present paper focuses on the lack of regulation for the cryptocurrency and their allied sectors, a major concern among the international community. Many nations such as Singapore and China have already started to venture out the prospects in the research fields related to regulating the cryptocurrency, and hence more such steps are needed by nations across the world. Cryptocurrency is a property or currency which could be decided as per the following policy of the respective state; however, when it comes to regularizing the cryptocurrency as a medium of transactions, there needs to be a global consensus among the states for holistic development of such filed of exploration.
Mazin Debe, Khaled Salah, Raja Jayaraman, Ibrar Yaqoob · 5 authors
Resource-constrained blockchain clients and the Internet of Things (IoT) devices pose limitations in terms of processing and storing the entire blockchain ledger and mining blocks. Such clients and devices rely on a view of the blockchain provided by full nodes acting as gateways. However, gateway nodes sometimes can provide a distorted view of the blockchain that makes lightweight clients vulnerable to the eclipse attack. When under such an attack, a client cannot differentiate between a forked view of the blockchain and the legitimate blockchain ledger leading to fatal consequences and huge losses incurred. In this paper, we propose a data attestation solution that employs full nodes as validators to attest the responses reported by gateways of lightweight nodes. We leverage smart contracts to give lightweight clients confidence in the data reported as they are unable to validate it from the blockchain network themselves. The system governs the attestation process that comprises submitting attestation requests, approving them, recording the response of validators, and manage payments. Clients can, thereafter, provide their feedback about the validator/gateway performance in the form of a reputation score. We present the proposed system architecture and describe its implementation on the Ethereum blockchain network. We evaluate the proposed solution with respect to functionality testing, cost of execution, and security analysis of the developed smart contracts. We make our smart contracts code and testing scripts publicly available.
COVID-19 pandemic has caused significant losses and an increase in the level of risk in the financial markets and global economy. Thus in this study, we model the crypto market volatility behavior during the COVID-19 crisis. GARCH (1, 1) and GJR-GARCH (1, 1) were applied to model the volatility clustering and leverage effects in the intraday day (15-minute interval) returns of Bitcoin, Ethereum, and Litcoin ranging from 11th April 2019 to 8th February 2021. The empirical findings from GARCH (1, 1) model indicates the presence of volatility clustering in the crypto market. Moreover, the results of the GJR-GARCH (1, 1) indicate the presence of leverage effects in the financial returns series of all three crypto currencies. Furthermore, the excess kurtosis confirms the existence of fat-tail phenomena in the crypto market. Overall, the findings from this study showed that in times of COVID 19 pandemic the crypto market returns series showed volatility persistence, fat-tail phenomena, and leverage effects. These outcomes provide a better understanding for financial investors to invest rationally and cautiously during pandemic times.
Sahar Loukil, Mouna Aloui, Ahmed Jeribi, Anis Jarboui
This study examines the safe haven properties of top five crypto-currencies, oil and gold for the five gulf cooperation council countries in view of COVID-19 period through a nonlinear and asymmetric framework NARDL methodology to uncover short- and long-run asymmetries. Using daily data from January 2019 to April 2020, we find that Bitcoin and Ethereum are safe haven assets for GCC in instability; Bitcoin is a safe haven for Oman, Saudi Arabia and Abu Dhabi. Ethereum is a safe haven for Bahrain, Kuwait and Qatar. Further, for Kuwait, Qatar, Saudi Arabia and Abu Dhabi, oil is a safe haven asset in mitigated period. We also notice that the strategies of hiding differ interestingly for all countries except for Saudi Arabia that does not significantly change its strategies. Thus, portfolio managers may consider few eligible crypto-currencies and oil for their inclusion into the portfolio to hedge risk. While, speculators acting in both stock and crypto market may go for a spread strategy. Our research is useful for portfolio managers and financial advisors looking for the best of crypto's, gold and oil to hedge shocks in stock market indices.
In recent years, blockchain is utilized practically as a distributed secure digital ledger of some sorts of transactions. Blockchain is regarded as one of the most important next generation infrastructure technologies of the financial industry, as well as artificial intelligence and big data. In 2020, cryptocurrencies based on blockchain, such as Bitcoin, Ethereum, or XRP, have a value of more than $450 billion in the market capitalization. Furthermore, on blockchains such as Ethereum, transactions can also represent automatic executions of programs, which are called smart contracts. Thus, many institutes in various categories show their positive attitude toward processing financial transactions or non-financial contracts on blockchain. Although many researchers have studied for various types of issues on blockchain, there always exist security and privacy concerns for blockchain. In this paper, we point out a new concern for abusing the publicity of blockchain and also show the possibility of suspicions aroused by the concern. Then we propose a selective mechanism for self-protecting against the approach from crimes or computer viruses on blockchain, whether the disclosure of user's privacy occurs or not. Next, we also propose a concrete implementation of our proposed selective mechanism with two new address types. We aim to incorporate the mechanism in Bitcoin Core, which is the official Bitcoin client software, and using libbitcoin library functions for Bitcoin software development. We show experimental results to estimate overhead costs for processing our proposed address types toward processing the current standard address type in nodes on the peer-to-peer network.
Abstract With the promotion of “Internet +” and smart cities, as an important data voucher, electronic certificate brings great convenience to people’s life. However, the phenomenon of “data island” based on the electronic certificate database of each city hinders the sharing of an electronic certificate. In addition, problems such as centralization of data storage, poor security, and tamper-proof modification are common in electronic certificate libraries. To solve these problems, we present a blockchain-based electronic certificate sharing scheme, which uses the InterPlanetary File System (IPFS) and Ethereum smart contract to achieve secure storage and data sharing of electronic certificate by taking advantage of the non-tampering and decentralization of blockchain. At the same time, we achieve fine-grained access control by using attribute-based encryption of ciphertext policy and assigning attribute keys to users without affecting retrieval efficiency. Finally, through the simulation and performance analysis of the Ethereum test network, the analysis results show that our scheme is effective and feasible.
Jan 1, 2021·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Francesca Fallucchi, Marco Gerardi, Michele Petito, Ernesto William De Luca
In an ever more digitized world where information and data are increasingly dematerialized, the question of how to certify intellectual property and define when a document has been created or modified without the presence of any third-party guarantor inevitably arises. This document proposes a decentralized method that, by exploiting blockchain technology and distributed peer-to-peer (P2P) networks, makes it possible to historicize information in such a way that it is not possible for a user to alter its dating, attribute ownership or modify it by impersonating the author. The data certification (document, image, film, data archive, etc.) takes place through the creation of an immutable relationship between the owner and the data. At the legal level, many countries are beginning to regulate blockchain technology so that it can be used in many areas, such as the production chain, the Internet of Things or Public Administration. In this paper we present a solution to promote digital government and greater transparency, through the use of a framework based on the Ethereum blockchain, smart contracts and a decentralized application.
Abstract Vehicle automation is one of the main applications of industry 4.0 especially for tourism companies who provide their vehicles to migrants for traveling purposes. It is difficult to maintain trust among the travel agency and the customers. Although there are many existing solutions in the research that addresses the trust issues, but most of the solutions are based on centralized architecture such as cloud computing where the data is prone to various security threats. Motivated by the aforementioned discussion, the authors have proposed a vehicle tracking system based on the integration of blockchain and IoT in this paper. The proposed system will increase the trust among the entities by providing them transparency in tracking details of the vehicle. As the trip details are immutable and decentralized in nature, so, blockchain is used to store the details. Also, the system will generate the trip summary that contains the route detail, the number of kilometres travelled and the total cost of the trip. Tools such as Ethereum, Remix IDE, MetaMask, and RinkeyBy have been used to measure the performance of the system.
Image authentication is an important field that employs many different approaches and has several significant applications. In the proposed approach, we used a combination of two techniques to achieve authentication. Image watermarking is one of the techniques that has been used in many studies but the authentication field still needs to be studied. Blockchain technology is a relatively new technology that has significant research potential related to image authentication. The watermark is embedded into the third-level discrete wavelet transform (DWT) in the middle frequency regions to achieve security and imperceptibility goals. Peak signal-to-noise ratio PSNR, structural similarity matrix (SSIM), normalized correlation coefficient (NCC), and bit error rate (BER) are used to measure the performance of image watermarking. We used blockchain technology to avoid involving a trusted third party for authentication. Secure Hash Algorithm 256 (SHA-256) is applied on the watermark to save it into the blockchain. The watermark is encrypted using Advanced Encryption Standard (AES) and embedded into the image. The proposed method is tested on the USP SICI database and the MedPix medical image database. Ethereum blockchain is used to provide security, anonymity, and integrity of data with no third-party intervention. The proposed solution demonstrates enhanced security for image authentication compared with the state-of-the-art.
Open access
Advanced Steganography and Watermarking Techniques
A adoção de blockchain e contratos inteligentes tem se demonstrado uma opção valiosa para organizações inovarem em seus sistemas de informação. Nesse sentido, presencia-se também uma adesão ao desenvolvimento open source por parte dos envolvidos em tal ecossistema de soluções, especialmente com base na plataforma Ethereum e no uso do GitHub. Porém, apesar da presença de pesquisas prévias com foco na manutenção de contratos inteligentes, constata-se uma lacuna de pesquisa quanto 1) a análise do efeito que o processo de deploy na Ethereum exerce sobre os projetos open source em termos colaborativos e 2) na compreensão sobre o que efetivamente mudou nos repositórios após tal processo. Como fruto de uma pesquisa em andamento, este artigo contribui ao discutir um desenho de pesquisa exploratório pautado em Mineração em Repositórios de Software para compreender o efeito do processo de deploy na Ethereum em repositórios open source de contratos inteligentes.