Due to the quick increase of IoT devices, they lack the authentication standards and administration needed to keep user data secure. Hackers could cause significant infrastructure harm by infiltrating a wide spectrum of IoT devices. Blockchain use in IoT technology guarantees trust and authentication across all IoT elements, resulting in IoT security. Blockchain is a decentralized, distributed, and shared database that enables the creation of decentralized apps. Traceability, openness, immutability, and fault tolerance are some of the qualities of this technology that help maintain data privacy in IoT scenarios and thus create a safe environment. We look at a potential strategy for securely controlling IoT devices,i.e., devices connected to the internet using smart contracts on the blockchain in this study. This paper demonstrates how the proposed system comprising of a blockchain and smart contracts work efficiently in concurrence to avoid tampering by unauthorized parties. We have employed web3 library to control the linked devices by implementing Ethereum nodes (second most popular blockchain) on Raspberry Pi simulations and node.js.
Ifteher Alom, Md Sadek Ferdous, Mohammad Jabed Morshed Chowdhury
Blockchain Technology is an emerging technology with the potential to disrupt a number of application domains. Though blockchain platforms like Bitcoin and Ethereum have seen immense success and acceptability, their nature of being public and anonymous make them unsuitable for many enterprise level use-cases. To address this issue, Linux Foundation has started an open source umbrella initiative, known as the Hyperledger Platforms. Under this initiative, a number of private blockchain platforms have been developed which can be used for different enterprise level applications. However, the scalability and performance of these private blockchains must be examined to understand their suitability for different use-cases. Recent researches and projects on performance benchmarking for private blockchain systems are very specific to use-cases and are generally tied to a blockchain platform. In this article, we presentBlockMeter, an application agnostic performance benchmarking framework for private blockchain platforms. This framework can be utilised to measure the key performance matrices of any application deployed on top of an external private blockchain application in real-time. In this article, we present the architecture of the framework and discuss its different implementation aspects. Then, to showcase the applicability of the framework, we use BlockMeter to evaluate the two most widely used Hyperledger platforms, Hyperledger Fabric and HyperledgerSawtooth, against a number of use-cases.
Objective. The aim of the work is to determine the prospects for the development of digital financial instruments in the management of social and economic systems. Method. The comparative analysis of the results of an anonymous survey using interactive multi-user social networks was used as research methods in the work. Result. The factors and key parameters influencing the development of cryptocurrency mechanisms are revealed, the advantages and disadvantages of using digital tools are identified. Suggestions for the management of cryptocurrency instruments and recommendations for improving the reliability and development of digital instruments in the financial and digital environment are given. The results of the analysis of a survey of 1121 respondents on the topic of using cryptocurrencies are presented. The results of the study showed that the most commonly used cryptocurrencies are Bitcoin and Ethereum, with a significant proportion of respondents preferring digital activities such as mining and trading. At the same time, a significant number of respondents believe that the future development of digital financial instruments is directly dependent on the legitimization of cryptocurrencies by the state and improvement of blockchain technology. Conclusion. The development of cryptocurrencies cannot be assessed unambiguously. With the development of cryptocurrency instruments, a number of threats arise, which include significant volatility, the presence of legislative restrictions on their use, and the inability to withdraw operations. The further development of cryptocurrencies should be associated with the legal regulation of their distribution, both at the national and international levels, which will ensure the determination of their legal status among other monetary units. It is also necessary to carry out a phased introduction of cryptocurrencies into payment systems for cash settlements, which should be carried out on the basis of the organization of the official circulation of cryptocurrencies and blockchain technology.
Grassroots currencies are means for turning mutual trust into liquidity, with the goal of providing foundations for grassroots digital economies. Grassroots coins are units of debt that can be issued by anyone -- people, corporations, cooperatives, banks, municipalities and governments -- and traded by anyone. They are more similar to `inside money' (a medium of exchange backed by private credit) and to fiat currencies (for which the issuer controls scarcity) than to global cryptocurrencies such as Bitcoin or Ethereum, which are unbacked and for which scarcity is controlled by the protocol. In this paper we introduce the principles that underlie grassroots currencies; show that they naturally admit basic fiat currency measures regarding foreign trade such as foreign debt, trade balance, and velocity, and basic accounting measures such as cash ratio, quick ratio, and current ratio; elaborate economic scenarios enabled by these principles for grassroots currencies issued by natural and legal persons; relate grassroots currencies to extant work, including notions of personal currencies, community currencies, cryptocurrencies, and inside money; formally specify grassroots currencies as digital entities, governed by the Grassroots Currencies Protocol; discuss the security (safety, liveness, and privacy) of the protocol; and prove that the protocol is grassroots. An implementation of grassroots currencies via a blocklace-based payment system is described elsewhere.
Flavio Corradini, Alessandro Marcelletti, Andrea Morichetta, Andrea Polini · 6 authors
A key challenge in engineering distributed systems consists in the integration into their development of a decentralised infrastructure allowing the system participants to trust each other. In this article, we face such a challenge by proposing a model-driven methodology and a related framework to support the engineering of trustable and auditable systems. The approach is based on choreography diagrams specified in the Business Process Model and Notation standard, describing the interactions that should occur among the distributed components of systems. We support the whole lifecycle of choreographies, from their modelling to their distributed execution and auditing. The framework, based on blockchain technology, is named ChorChain. More specifically, ChorChain takes as input a BPMN choreography model and automatically translates it into a Solidity smart contract. The smart contract permits us to enforce the interactions among the cooperating components as prescribed by the choreography model. By leveraging on the auditability of blockchain, ChorChain also supports the activity of auditors continuously. In such a way, ChorChain enables auditors to get some degree of assurance on what happens simultaneously with, or shortly after, information disclosure. We assess the feasibility and effectiveness of the proposed methodology and framework through experiments conducted on the Rinkeby Ethereum Testnet.
The implementation of blockchain technology by various businesses has gained impetus at the same time as within the finance area it is achieving new heights progressively. To generate a distributed ledger a blockchain (data structure) is utilized. Basically, a blockchain is a collection of (a page of a ledger or record book) i.e. blocks in a sequential fashion. A record book holds all dealings, timestamps, the hash value of the preceding block, record book compensation, record book number, and others. Each single record book holds a hash value of the preceding record book or block, therefore making a series of record books accompanying one another. In this research work, while discovering these DApps, we will discover them at a stage that is sufficient to comprehend in what way they work and manage various concerns. In this research work, we will deliberate and recognize Blockchain arrangement, how Ethereum works, writing smart contracts, the introduction of web3.js, and wallet services. Finally, we put forward promising clarifications in detail for improving the safety of the distributed ledger for industrialized applications
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
The popularity of blockchain technology led to the development of many web platforms with different functionalities. Ethereum, a decentralized, open-source blockchain featuring smart contracts, introduces an interesting ecosystem of human users and autonomous agents (the contracts). It is the most actively used blockchain platform, hosting ether, the second largest cryptocurrency by market capitalization, as its native store of value. The Ethereum blockchain contains a vast amount of user-to-user, user-to-contract, contract-to -user, and contract-to-contract interactions that can be modeled as complex networks. To mine these interactions as graphs through a preferred analytics toolbox, an end-user has to extract, transform, and load (ETL) the required data into the desired network format. However, it is costly and time-consuming to manage the ETL pipeline for the massive and complex blockchain data. To support research in this domain, we develop an end-to-end, automated tool - EtherNet, which performs ETL tasks from a single source of truth (Google BigQuery), and provides graph equivalent representations for visualization and mining on the entire Ethereum blockchain network.
Purpose This study aims to analyze the time-varying correlation between the cryptocurrency policy uncertainty (UCRY Policy) and cryptocurrency returns. More specifically, it analyzes whether these correlations vary according to the uncertainty attributable to salient events such as China banning ICOs, cryptocurrency exchanges attacks, Coronavirus (Covid-19) pandemic crisis and the United States (U.S.) Security and Exchange Commissionâs (SECâs) announcement about Ripple. Design/methodology/approach To measure the dynamic relationship, it uses the dynamic conditional correlation (DCC) model of Engle (2002) to consider time variation in UCRY Policy and cryptocurrency returns. The data set encompasses the weekly frequency data of the UCRY Policy and Bitcoin (BTC), Ethereum (ETH), Litecoin (LTC), Ripple (XRP), Stellar (XLM), Dash (DASH), Monero (XMR) from 4 September 2016, to 21 February 2021. Findings Empirical findings indicate that the correlations between the UCRY Policy and the BTC, ETH, LTC, XRP, XLM, DASH and XMR returns are consistently negative. Thus, an increase in the volatility of the UCRY Policy can lead to a decrease in volatility for BTC, ETH, LTC, XRP, XLM, DASH and XMR returns. Besides, these findings indicate that the estimated DCC is not only time-varying but also substantially responsive to salient events, such as China banning ICOs, cryptocurrency exchanges attacks, the Covid-19 pandemic crisis and SECâs announcement about Ripple. Besides, empirical findings show that cryptocurrency returns are adversely impacted by UCRY Policy during the salient events (China bans ICOs, the hack of cryptocurrency exchanges, Covid-19 crisis), suggesting their failure to act as a hedge or safe-haven asset. Originality/value To the best of the authorâs knowledge, this study investigates the time-varying correlation between UCRY Policy and cryptocurrency returns. Besides, this study may be useful for new studies and fill a gap in the finance literature, due to the limited number of studies on the UCRY Policy in the finance literature.
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Yang Ming, Chenhao Wang, Hang Liu, Yi Zhao · 7 authors
As the rapid proliferation of Internet of Things (IoT) and edge computing, large amounts of data are needed to be stored and transmitted in the online storage system. Data deduplication can be adopted to improve communication efficiency and minimize storage space. However, in edge computing, data deduplication brings security and functionality requirements that are still unsatisfied. Most existing schemes are vulnerable to brute-force attacks and single-point attacks. Moreover, they impose a heavy burden on resource-constrained edge nodes and do not support cross-domain deduplication. Blockchain is a promising technology because the programmable smart contract can be utilized to perform cross-domain deduplication and guarantee the traceability of data. In this article, an efficient dynamic cross-domain deduplication scheme in blockchain-enabled edge computing is proposed to solve the above problems. Specifically, the smart contract is employed to assist cross-domain deduplication, which also can reduce the storage pressure of edge nodes. Meanwhile, a hash proof system-based oblivious pseudorandom function is created to reduce the time cost of key generation and achieve the security requirements of resistance to brute-force attacks and single-point attacks. The technology of accumulators is adopted to achieve Proofs of Ownership (PoO), which can prevent duplicate-faking attacks. The security analysis demonstrates that the proposed scheme has a higher security level. The performance evaluation shows that the proposed scheme significantly reduces computation cost and communication overhead, compared with other existing schemes. The smart contract is implemented in the Ethereum test network (i.e., Rinkeby), which shows acceptable gas cost even the functions are called frequently.
Predatory trading bots lurking in Ethereum's mempool present invisible taxation of traders on automated market makers (AMMs). AMM traders specify a slippage tolerance to indicate the maximum price movement they are willing to accept. This way, traders avoid automatic transaction failure in case of small price movements before their trade request executes. However, while a too-small slippage tolerance may lead to trade failures, a too-large slippage tolerance allows predatory trading bots to profit from sandwich attacks. These bots can extract the difference between the slippage tolerance and the actual price movement as profit. In this work, we introduce the sandwich game to analyze sandwich attacks analytically from both the attacker and victim perspectives. Moreover, we provide a simple and highly effective algorithm that traders can use to set the slippage tolerance. We unveil that most broadcasted transactions can avoid sandwich attacks while simultaneously only experiencing a low risk of transaction failure. Thereby, we demonstrate that a constant auto-slippage cannot adjust to varying trade sizes and pool characteristics. Our algorithm outperforms the constant auto-slippage suggested by the biggest AMM, Uniswap, in all performed tests. Specifically, our algorithm repeatedly demonstrates a cost reduction exceeding a factor of 100.
Jakub Sliwinski, Yann Vonlanthen, Roger Wattenhofer
Digital money can be implemented efficiently by avoiding consensus. However, no-consensus implementations have drawbacks, as they cannot support smart contracts, and (even more fundamentally) they cannot deal with conflicting transactions. We present a novel protocol that combines the benefits of an asynchronous, broadcast-based digital currency, with the capacity to perform consensus. This is achieved by selectively performing consensus a posteriori, i.e., only when absolutely necessary. Our on-demand consensus comes at the price of restricting the Byzantine participants to be less than a one-fifth minority in the system, which is the optimal threshold. We formally prove the correctness of our system and present an open-source implementation, which inherits many features from the Ethereum ecosystem.
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Blockchain - the decentralized global ledger technology provides a potentially attractive alternate to organize modern finance. Organizations use ERP software to integrate the management of all major business processes. Instead, blockchain can provide single version of the truth, in real time, regardless of constraints, to all participants across the organizational boundaries.
<p>Sertifikat merupakan sebuah bentuk penghargaan yang didapat seseorang setelah menyelesaikan suatu uji kompetensi atau pembelajaran tertentu. Sertifikat harus dibuat dan disimpan dengan metode dan keamanan yang baik untuk mencegah terjadinya perubahan isi atau bahkan pemalsuan. Teknologi blockchain merupakan teknologi yang memungkinkan proses penyimpanan yang aman dengan ongkos yang rendah. Keamanan terjamin karena semua orang bisa mengambil bagian untuk menyimpan data dengan ledger yang terdistribusi. Berdasarkan hasil penelitian dan perancangan sistem yang dibuat dapat disimpulkan bahwa proses pembuatan teknologi blockchain sebagai media penerbitan sertifikat dan validasinya dapat dibuat menggunakan program milik Ethereum yaitu Geth dan penyimpanan data menggunakan smart contract yang diterbitkan pada jaringan blockchain. Hasil dari pengujian reliabilitas terhadap sistem menunjukkan bahwa bahwa sistem berhasil memproses 200 transaksi dalam waktu kurang lebih 8 detik. Untuk pengujian skalabilitas didapatkan estimasi 10 juta blok membutuhkan kapasitas penyimpanan sebesar 22,6 GB untuk menjadi node atau miner pada jaringan blockchain ini.</p><p> </p><p><em><strong>Abstract</strong></em></p><p class="Abstract"><em>A certificate is a form of appreciation that a person receives after completing a certain competency or learning test. Certificates must be created and stored with good methods and security to prevent changes in content or even forgery. Blockchain technology is technology that allows secure storage processes at a low cost. Security is guaranteed because everyone can take part in storing data with a distributed ledger. Based on the results of research and design of the system, it can be concluded that the process of making blockchain technology as a media for issuing certificates and validation can be made using Ethereum's proprietary program Geth and data storage using smart contracts issued on the blockchain network. The results of the reliability testing of the system indicate that the system successfully processed 200 transactions in approximately 8 seconds. For scalability testing, it is estimated that 10 million blocks require a storage capacity of 22.6 GB to become a node or miner on this blockchain network.</em></p><p><em><strong><br /></strong></em></p>
Jaehyeon Kim, Sejong ÂLee, Yushin Kim, Sunghyun Cho
This paper discusses an attack scenario that infers identity in a blockchain-based smart healthcare system. There is a privacy vulnerability because blockchain data is open to all participants. Invasion of privacy is a significant problem in a blockchain-based smart healthcare system that utilizes personal information. We analyze the blockchain graph to infer a user's identity. Then, we construct account-transaction graphs using transactions on the blockchain. A graph embedding algorithm generates features of account-transaction graphs. The generated features are used to identify blockchain participants using machine learning algorithms. We evaluate our attack scenario by applying embedding algorithms in Ethereum. The results showed an inference performance of up to 0.94 in the f1-score.
Abstract The annual energy consumption of cryptocurrencies has been increasing in recent years. This paper studies the cryptocurrencies return volatility spillover and the underlying dynamics of five cryptocurrencies, namely Bitcoin, Bitcoin Cash, Ethereum, Ripple XRP and Litecoin's impact on four energy markets, namely Nifty Energy Index, S&P 500 Energy Index, S&P/TSX Canadian Energy Index and Shanghai Stock Exchange Energy Index for the period 2016â2021. We employed the Granger Causality Test and DCC MGARCH model to investigate the integration between cryptocurrencies and the energy markets. From the empirical analyses, we find that the overall timeâvarying correlation between cryptocurrencies and the energy markets is low and weak. This study may be helpful for investors, academia and policymakers.
Kazi Tamzid Akhter Md Hasib, Ixion Chowdhury, Saadman Sakib, Mohammad Monirujjaman Khan · 7 authors
Bangladesh should have owned a decentralized medical record server. We face a lot of issues, such as doctorâs appointments, report organization in one spot, and report follow-ups. People now bring a large number of papers to the doctorâs chamber. They carry prescriptions, reports, and X-ray files, among other things. It complicates everyoneâs life as a result. All of the reports must be reviewed by doctors on a regular basis. It is difficult to read old reports on a regular basis, and patients do not receive the correct medications or treatment. Doctors also find it extremely difficult to comprehend handwritten prescriptions. Data security, authenticity, time management, and other areas of data administration are dramatically improved when blockchain (smart contract) technology is linked with standard database management solutions. Blockchain is a groundbreaking, decentralized technology that protects data from unauthorized access. After smart contracts are implemented, the management will be satisfied with the patients. As a result, maintaining data privacy and accountability in the system is tough. It signifies that the information is only accessible to those who have been authenticated. This study focuses on limiting third-party engagement in medical health data and improving data security. Throughout the process, this will improve accessibility and time efficiency. People will feel safer during the payment procedure, which is the most significant benefit. A smart contract and a peer-to-peer encrypted technology were used. The hacker will not be able to gain access to this system since this document uses an immutable ledger. They will not be able to change any of the data if they gain access to the system. If the items are found to be defective, the transaction will be halted. Transaction security will be a viable option for recasting these problems using cryptographic methodologies. We developed a website where patients and doctors will both benefit because of the use of blockchain technology to ensure the security of medical data. We have different profiles for doctors and patients. In the patient profile, they can create their own account by using a unique address, name, and age. This unique address will be created from the genesis block. The unique address is completely private to the owner, who will remain fully secure in our network. After creating an account, the patient can view the doctorsâ list and they can upload their medical reports such as prescriptions and X-rays. All the records uploaded by the patient will be stored on our local server (Ganache). The records are stored as hashed strings of the data. Those files will also have a unique address, and it will be shown in the patient profile. After granting access, the doctors will be able to view their records in the respective doctorâs profile. For accessing the options such as uploading, viewing, or editing the data, Ethereum currency (a fee) will have to be paid in order to complete the request. On the other hand, doctors can enter their profile using their name and unique address. After logging in, they can view their name, unique address, and the list of patients that have granted access to the doctor to view their files. On our website, the front end is handled by JavaScript, ReactJS, HTML, and CSS. The backend is handled by Solidity. Storage is handled by Ganache as the local host. Finally, this paper will show how to ensure that the procedure is as safe as feasible. We are also maintaining transparency and efficiency here.
Werner Kristjanpoller, Leonardo H.S. Fernandes, Benjamin Miranda Tabak
Cryptocurrencies play a pivotal role in the financial market. Given this, we perform the asymmetric multifractal cross-correlation analysis to examine the weak form of the Efficient Market Hypotheses (EMH) considering two temporal scales. In the daily scale, we find that the pair BitcoinâLitecoin displays the largest multifractal spectrum. While, in the hourly scale, the pair BitcoinâEthereum presents the largest multifractal spectrum. Our empirical evidence has rejected the weak form of the EMH and clearly suggests that the dynamics of the analyzed cryptocurrency pairs are in line with the Fractal Market Hypothesis (FMH). Cross-correlation asymmetries are more persistent for small fluctuations than for large fluctuations. The results are essential for investors, portfolio and risk managers, and policymakers.
Summary Technological advancements play a crucial role in agriculture sector aiming at eradicating numerous problems. These problems are intensified due to pandemics like delay overhead in the subsidized agriâproducts supply chains. The existing technologyâbased solutions are not readily adopted by stakeholders due to absence of trust. Blockchain can impart more transparency and trust in agriâsupply chains leading to fair pricing. The idea of using blockchain for financing processes in agriculture has resulted from the managerial pressure and fiscal scams which eventually aggravate the plight of farmers. Thus, a blockchainâbased subsidized agriâproducts distribution (SAPD) is proposed. Blockchain has been optimized by a reputationâbased ProofâofâAuthority (PoA) consensus algorithm. It has been implemented using Ethereum blockchain on AWS EC2 cloud. The smart contract is designed in solidity. Detailed performance evaluation has been conducted to compute cost and processing time that shows a substantial reduction in cost of managerial operations with respect to previous work by 41.65%. Finally, to assess the utility of SAPD system a qualitative user survey has been conducted. Managerial significance of system is reflected in memory space reduction by 85% in light clients and increase in transaction execution per second by 31% using reputationâbased PoA.