Ethereum is a digital asset whose transactions are kept on a decentralized, globally accessible ledger. An Ethereum Blockchain owner's real identity is concealed behind a pseudonym termed an address. ...Because of this, Ethereum is frequently used in illegal activities like gambling and ransomware attacks because it is popularly believed to offer the highest level of anonymity. As a result, it is necessary to categorize the various malicious cybercriminal users' activities and addresses in the Ethereum Blockchain. The Blockchain's public data enables an in-depth analysis. Using supervised machine learning models including linear, non-linear, and ensemble learning models based on malicious and non-malicious activities, the classification of Ethereum Blockchain addresses is carried out in this paper. In this research work, cross-validation accuracy, recall, precision, and f1-score have been employed for the assessment. Findings indicate that linear and non-linear machine learning approaches are superior to ensemble learning for classifying Ethereum Blockchain addresses. The results also show that it is possible to discover the Ethereum Blockchain addresses of malicious users.
An integrated identity is a centralized identifier that makes it possible for customers to get access to a variety of business services from a single network. The risks and assaults include identity ...leaks, centralized management, auditing restrictions, and lengthy breach investigation procedures. The article presents a technique for creating a blockchain-based, integrated identification system in a marketplace by automating and decentralizing the creation and auditing of strong and secure attributes. When individuals engage in market transactions, they act as nodes in a distributed blockchain network, contributing to the development of federated identities. Using a single federated identity, members of this network are able to use any of the participating companies' services. In this, IoT sensors and wearables can automatically log real-time data for you while identifying patterns and flagging problems. The total transparency of all blockchain transactions provides participants the ability to see which services they're using and their users the ability to track the usage of their identities. To test the proposed architecture, implementation done on a public blockchain and a permissioned blockchain (Ethereum and Hyperledger Fabric).
A Survey on Ethereum Systems Security Chen, Huashan; Pendleton, Marcus; Njilla, Laurent ...
ACM computing surveys,
06/2020, Letnik:
53, Številka:
3
Journal Article
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Blockchain technology is believed by many to be a game changer in many application domains. While the first generation of blockchain technology (i.e., Blockchain 1.0) is almost exclusively used for ...cryptocurrency, the second generation (i.e., Blockchain 2.0), as represented by Ethereum, is an open and decentralized platform enabling a new paradigm of computing—Decentralized Applications (DApps) running on top of blockchains. The rich applications and semantics of DApps inevitably introduce many security vulnerabilities, which have no counterparts in pure cryptocurrency systems like Bitcoin. Since Ethereum is a new, yet complex, system, it is imperative to have a systematic and comprehensive understanding on its security from a holistic perspective, which was previously unavailable in the literature. To the best of our knowledge, the present survey, which can also be used as a tutorial, fills this void. We systematize three aspects of Ethereum systems security: vulnerabilities, attacks, and defenses. We draw insights into vulnerability root causes, attack consequences, and defense capabilities, which shed light on future research directions.
We examine the existence and dates of pricing bubbles in Bitcoin and Ethereum, two popular cryptocurrencies using the (Phillips et al., 2011) methodology. In contrast to previous papers, we examine ...the fundamental drivers of the price. Having derived ratios that are economically and computationally sensible, we use these variables to detect and datestamp bubbles. Our conclusion is that there are periods of clear bubble behaviour, with Bitcoin now almost certainly in a bubble phase.
•A novel scheme is proposed for IoT-based healthcare systems to generate and maintain medical certificates.•The proposed blockchain system ensures the security of medical certificates.•In the ...proposed scheme, the Merkle root hash of the medical certificate is maintained with a unique transaction identity.•Experimental results prove the efficiency of the proposed scheme over the existing schemes.
Nowadays, blockchain technology is one of the advanced technologies to ensure the security of users’ sensitive or confidential data. Blockchain technology plays a vital role in various applications like artificial intelligence, supply chain, cloud computing, the healthcare sector, and many more. It helps the healthcare domain to get benefitted from its many advanced features, such as confidentiality, decentralization, security, and privacy. Also, the Internet of Things (IoT) devices connect with the healthcare systems, and the healthcare sector application software further communicates with the IT industry. The blockchain-based IoT systems have significantly impacted the healthcare sector by enhancing security, privacy, transparency, and efficiency, providing better business opportunities. Moreover, traditional healthcare systems face severe security and privacy problems, such as phishing, masquerades, identity theft, and many others. Thus, a secure blockchain-based Proposed Application (PA) is designed to generate, maintain, and validate healthcare certificates. The PA acts as a communication medium between the backend blockchain network and application entities like hospitals, patients, doctors, and IoT devices to create and verify medical certificates. It also ensures various security features, namely confidentiality, authentication, and access control, using the concept of smart contracts. The comparative and performance analysis of the proposed work shows that it provides a more effective solution than the existing schemes.
•We utilize the COVID-19 pandemic announcement as the setting to test the safe-haven properties of Bitcoin and Ethereum.•Bitcoin and Ethereum exhibit short-term safe-haven properties.•Ethereum is ...potentially a better safe-haven than Bitcoin.•However, both cryptocurrencies exhibit high volatilities.
Utilizing the WHO COVID-19 pandemic statement, we test Bitcoin and Ethereum as safe-havens for stocks. We find that the two largest cryptocurrencies are suitable as short-term safe-havens. The DCC and cDCC results show that their daily returns tend to correlate with S&P500 return negatively during the pandemic. The regression results also robustly support the safe-haven features and uncover that Ethereum is possibly a better safe-haven than Bitcoin. However, we note that both coins exhibit high volatilities. Before (during) the pandemic daily volatilities of Bitcoin, Ethereum, gold, and the S&P500 are 3.44% (9.11%), 4.34% (10.96%), 0.89% (2.19%), and 1.27% (6.07%), respectively.
The increasing complexity of cloud computing has prompted a greater emphasis on protecting the privacy, integrity, and security of data stored and processed in the cloud. Data privacy is safeguarded ...through access control, but existing models such as Role Based Access Control (RBAC) and Attribute Based Access Control (ABAC) rely on a centralized server. If this server is compromised, it poses significant risks to data security. To address this issue, there is a need for Distributed ABAC (DABAC) system for OpenStack services based on blockchain. The unique features of blockchain enables access control systems which ensures data integrity and privacy. Additionally, blockchain offers a level of transparency for both the resource owner and a user. In this work, we propose a smart contract based ABAC system. We implemented the proposed work using an Ethereum blockchain and OpenStack cloud. Furthermore, we evaluated two consensus algorithms for scalability analysis of DABC mechanism. The results demonstrate that DABAC performs better than ABAC in ensuring fine-grade access control with proof of stake consensus algorithm providing better scalability.
IoTs are integrated, interconnected concepts of things or objects in our surroundings, with an essence of virtualization. The interconnectivity of the business world, health environments, smart home ...devices, and daily use gadgets takes place through the networks based on cloud infrastructure which is not restricted to jurisdictional, geographic, and national boundaries. However, the light-weight IoT devices come with a limited storage and processing capacity. Due to this limitation, the need for separate data storage arises so that data can be utilized in the future. These third-party storage services are provided at the cost of a user’s privacy. Furthermore, the storage relies on a centralized database which is more open to attack due to its single point security breach chances. Furthermore, present IoT data is not trustworthy in the external environment, as data manipulation is lacking when data is shared with other parties. To overcome the above-mentioned limitations of IoT, the emerging secure decentralized storage technology; Blockchain, have begun to abandon the significant impact in the IoT with the enhancement of security and incorporating a large number of devices in the today’s ecosystems. In this paper, we have performed a comprehensive literature review to show how well blockchain has transformed the smart environments connected with IoT sensors and the underlying issues for its adaptation. Further, a well-organized taxonomy is presented by highlighting the strengths, weaknesses, opportunities, and threats (SWOT) of blockchain based IoT environment. In addition to that, we have clearly presented the verities of blockchain applications such as bitcoin (earlier cryptocurrency used in blockchain) or ethereum (establish smart contracts) based works and pinpoint the necessities and security challenges. Moreover, we have highlighted the essential implementation requirements of blockchain in the IoTs. This paper is also equipped with a state-of-the-art framework of IoT while adopting security features and decentralized storage requirements of the blockchain. In the end, we have presented insightful challenges need to be addressed to obtain efficient, secure, and effective communication goals and to provide private and secure services for users as per their requirements.
•In this paper, we have performed a comprehensive literature review to show how well blockchain has transformed the smart environments connected with IoT sensors and the underlying security issues for its adaptation.•A well-organized taxonomy is presented by highlighting the strengths, weaknesses, opportunities, and threats (SWOT) of blockchain based IoT environment.•We have compared existing blockchain applications such as bitcoin (earlier cryptocurrency used in blockchain) or ethereum (establish smart contracts) based works and pinpoint the necessities and security challenges for IoTs.•We have highlighted the essential implementation requirements of blockchain in the IoTs.•A state-of-the-art framework of IoT while adopting security features and decentralized storage requirements of the blockchain is presented.•Last but not least, we have presented insightful security challenges need to be addressed in adaptation of blockchains in IoTs.
Data leakage in electronic health records (EHRs) could result in the compromise of patient privacy (e.g. medical conditions). Generally most data in EHRs remain unchanged once they are uploaded to ...the system; thus, blockchain can be potentially used to facilitate the sharing of such data. Different participating medical organizations and individuals (e.g. medical practitioners, hospitals, medical labs and insurance companies) can then access EHRs stored on the blockchain with a higher level of confidence. In this paper, a blockchain based searchable encryption scheme for EHRs is proposed. The index for EHRs is constructed through complex logic expressions and stored in the blockchain, so that a data user can utilize the expressions to search the index. As only the index is migrated to the blockchain to facilitate propagation, the data owners have full control over who can see their EHRs data. The use of blockchain technology ensures the integrity, anti-tampering, and traceability of EHRs’ index. Finally, the performance of the proposed scheme is evaluated from two aspects, namely in terms of the overhead for extracting the document IDs from EHRs and the overhead associated with conducting transactions on smart contract in Ethereum.
•Blockchain based searchable encryption for electronic health record sharing.•File encryption, index construction, transaction generation and searching.•Designated smart contract in blockchain to facilitate monetary rewarding.
In recent years, Bitcoin and Ethereum have witnessed a surge in trading activity, driven by venture capital investment and funding through initial coin offerings (ICOs) and initial exchange offerings ...(IEOs). This heightened interest has led to kickstarting a vibrant ecosystem for blockchain development. The total number of cryptocurrencies listed on CoinMarketCap.com has reached 2,274 highlights how dynamic and wide blockchain development landscape has grown. In blockchain development, new blockchain projects are being created by forking blockchains inspired by major cryptocurrencies such as Bitcoin and Ethereum. These projects aim to address the perceived shortcomings and improve existing technologies. Altcoins, representing these alternative cryptocurrencies, are an ongoing industry effort to improve performance and security with enhancement proposals such as Bitcoin Improvement Proposals (BIP), Ethereum Improvement Proposals (EIP), and EOSIO Enhancement Proposals (EEP). With competitive attempts to improve blockchain performance and security, an ongoing performance race between various blockchains has taken shape, each claiming its own performance advantages. In this paper, we describe the transactions contained in the blocks of each representative blockchain, and find the factors that affect the transactions per second (TPS) through transaction processing and block generation processes, and suggest their relationship with scalability.
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