In this paper, author analyses the role of cryptocurrencies in the economy and showed the trends of prices of Bitcoin and Ethereum in terms of US$ during 2017m1-2021m12 and also showed the trends of the market capitalization of Bitcoin during 2017m1-2021m12. All the trendlines are non-linear with cyclical behavior. Traditional regression model revealed that the market capitalization of Bitcoin is positively related with prices of Bitcoin and inflation rate and negatively related with price of Ethereum significantly from 2019m1 to 2021m12. Cointegration and VEC model suggested that the market capitalization of Bitcoin has long run causality with the prices of Bitcoin and Ethereum and inflation rate but the cointegrating equation has been proved diverging away from equilibrium. Bitcoin price and market capitalization have bi-directional short run causality and the price of Ethereum has short run causality to market capitalization of Bitcoin during the specified period. The volatility of market capitalization of Bitcoin showed a non-stationary process.
Intelligent Transport Systems (ITSs) play an important role in future smart city design to improve traffic safety and traffic congestion by sharing data collected by vehicles. For sharing the traffic data with other vehicles, the vehicular sensory data are usually uploaded to the cloud server. However, existing data sharing systems for VANETs cannot provide selective data with sufficient privacy protection. Moreover, some schemes also cannot ensure stable data accessibility and the integrity of retrieved data. On the other hand, with the improvements such as lower latency, higher capacity, and increased bandwidth, 5G technology brings more possibilities to future applications. The join of the software-defined networks (SDNs) also offers efficient and effective network management. This paper proposes a primitive vehicular communication system named blockchain-based privacy-preserving and sustainable data query service. The proposed scheme is designed to realize stable data accessibility by leveraging smart contracts and blockchain oracle. With the help of 5G technology and P2P file-sharing system, InterPlanetary File System (IPFS), the proposed scheme aims to support video downloading files with searchable capability and fairness. An incentive token mechanism is also equipped. The merit of auditability is ensured by Ethereum blockchain platform to support the accountability. Besides, we also evaluate its networking performance via SUMO and NS-3 simulators. Our simulation results show that the request-response delay of BPSDQS is less than existing blockchain-based proxy re-encryption (PRE) scheme. Our simulation results also showed that the average request-response delay in our scheme can saving up to 98%.
Abstract This study investigates the dynamic mechanism of financial markets on volatility spillovers across eight major cryptocurrency returns, namely Bitcoin, Ethereum, Stellar, Ripple, Tether, Cardano, Litecoin, and Eos from November 17, 2019, to January 25, 2021. The study captures the financial behavior of investors during the COVID-19 pandemic as a result of national lockdowns and slowdown of production. Three different methods, namely, EGARCH, DCC-GARCH, and wavelet, are used to understand whether cryptocurrency markets have been exposed to extreme volatility. While GARCH family models provide information about asset returns at given time scales, wavelets capture that information across different frequencies without losing inputs from the time horizon. The overall results show that three cryptocurrency markets (i.e., Bitcoin, Ethereum, and Litecoin) are highly volatile and mutually dependent over the sample period. This result means that any kind of shock in one market leads investors to act in the same direction in the other market and thus indirectly causes volatility spillovers in those markets. The results also imply that the volatility spillover across cryptocurrency markets was more influential in the second lockdown that started at the beginning of November 2020. Finally, to calculate the financial risk, two methods—namely, value-at-risk (VaR) and conditional value-at-risk (CVaR)—are used, along with two additional stock indices (the Shanghai Composite Index and S&P 500). Regardless of the confidence level investigated, the selected crypto assets, with the exception of the USDT were found to have substantially greater downside risk than SSE and S&P 500.
The misuse of health data stored in the Electronic Health Record (EHR) system can be uncontrolled. For example, mishandling of privacy and data security related to Corona Virus Disease-19 (COVID-19), containing patient diagnosis and vaccine certificate in Indonesia. We propose a system framework design by utilizing the InterPlanetary File System (IPFS) and Blockchain technology to overcome this problem. The IPFS environment supports a large data storage with a distributed network powered by Ethereum blockchain. The combination of this technology allows data stored in the EHR to be secure and available at any time. All data are secured with a blockchain cryptographic algorithm and can only be accessed using a user's private key. System testing evaluates the mechanism and process of storing and accessing data from 346 computers connected to the IPFS network and Blockchain by considering several parameters, such as gas unit, CPU load, network latency, and bandwidth used. The obtained results show that 135205 gas units are used in each transaction based on the tests. The average execution speed ranges from 12.98 to 14.08 GHz, 26 KB/s is used for incoming, and 4 KB/s is for outgoing bandwidth. Our contribution is in designing a blockchain-based decentralized EHR system by maximizing the use of private keys as an access right to maintain the integrity of COVID-19 diagnosis and certificate data. We also provide alternative storage using a distributed IPFS to maintain data availability at all times as a solution to the problem of traditional cloud storage, which often ignores data availability. Doi: 10.28991/esj-2021-SP1-013 Full Text: PDF
Juan Carlos Cañar Uyaguari, Ricardo Vinicio Jara Jara
El proyecto llevado a cabo consiste en desarrollar una aplicación descentralizada (DApp), que permita el registro de presencias y ausentismos, para su implementación se hizo uso de herramientas como Ethereum Blockchain y de Smart Contracts, tecnologías orientadas a la Web 3.0 que ofrecen números beneficios, tales como seguridad, descentralización de la información y transaccionalidad entre distintos entes sin la necesidad de intermediarios, permitiendo que la información almacenada en la Blockchain sea transparente para el usuario y a su vez se convierta en inmutable.
Sharding is a solution to the blockchain scalability problem. A sharded blockchain divides consensus nodes (validators) into groups called shards and processes transactions separately to improve throughput and latency. In this paper, we analyze the rational behavior of users in account/balance model-based sharded blockchains and identify a phenomenon in which accounts (users' wallets and smart contracts) eventually get concentrated in a few shards, making shard loads unfair. This phenomenon leads to bad user experiences, such as delays in transaction inclusions and increased transaction fees. To solve this problem, we propose two load balancing methods in account/balance model-based sharded blockchains. Both methods perform load balancing by periodically reassigning accounts: in the first method, the blockchain protocol itself performs load balancing and in the second method, wallets perform load balancing. We discuss the pros and cons of the two protocols, and apply the protocols to the execution sharding in Ethereum 2.0, an existing sharding design. Further, we analyze by simulation how the protocols behave to confirm that we can observe smaller transaction delays and fees. As a result, we released the simulation program as “Shargri-La,” a simulator designed for general-purpose user behavior analysis on the execution sharding in Ethereum 2.0.
In Bitcoin and Ethereum, nodes require a large storage capacity to maintain all of the blockchain data such as transactions. As of September 2021, the storage size of the Bitcoin blockchain has expanded to 355 GB, and it has increased by approximately 50 GB every year over the last five years. This storage requirement is a major hurdle to becoming a block proposer or validator. We propose an architecture called Trail that allows nodes to hold all blocks in a small storage and to generate and validate blocks and transactions. A node in Trail holds all blocks without transactions, UTXOs or account balances. The block size is approximately 8 kB, which is 100 times smaller than that of Bitcoin. On the other hand, a client who issues transactions needs to hold proof of its assets. Thus, compared to traditional blockchains, clients must store additional data. We show that proper data archiving can keep the account device storage size small. Then, we propose a method of executing smart contracts in Trail using a threshold signature. Trail allows more users to be block proposers and validators and improves the decentralization and security of the blockchain.
Internet of Things (IoT) devices are widely used in many industries including smart cities, smart agriculture, smart medical, smart logistics, etc. However, Distributed Denial of Service (DDoS) attacks pose a serious threat to the security of IoT. Attackers can easily exploit the vulnerabilities of IoT devices and control them as part of botnets to launch DDoS attacks. This is because IoT devices are resource-constrained with limited memory and computing resources. As an emerging technology, Blockchain has the potential to solve the security issues in IoT. Therefore, it is important to analyse various Blockchain-based solutions to mitigate DDoS attacks in IoT. In this survey, a detailed survey of various Blockchain-based solutions to mitigate DDoS attacks in IoT is carried out. First, we discuss how the IoT networks are vulnerable to DDoS attacks, its impact over IoT networks and associated services, the use of Blockchain as a potential technology to address DDoS attacks, in addition to challenges of Blockchain implementation in IoT. We then discuss various existing Blockchain-based solutions to mitigate the DDoS attacks in the IoT environment. Then, we classify existing Blockchain-based solutions into four categories i.e., Distributed Architecture-based solutions, Access Management-based solutions, Traffic Control-based solutions and the Ethereum Platform-based solutions. All the solutions are critically evaluated in terms of their working principles, the DDoS defense mechanism (i.e., prevention, detection, reaction), strengths and weaknesses. Finally, we discuss future research directions that can be explored to design and develop better Blockchain-based solutions to mitigate DDoS attacks in IoT.
Smart contracts are becoming more and more popular in financial scenarios like medical insurance. Rather than traditional schemes, using smart contracts as a medium is a better choice for both participants, as it is fairer, more reliable, more efficient, and enables real-time payment. However, medical insurance contracts need to input the patient's condition information as the judgment logic to trigger subsequent execution. Since the blockchain is a closed network, it lacks a secure network environment for data interaction with the outside world. The Data feed aims to provide the service of the on-chain and off-chain data interaction. Existing researches on the data feed has solved the security problems on it effectively, such as Town Crier, TLS-N and they have also taken into account the privacy-preserving problems. However, these schemes cannot actually protect privacy because when the ciphertext data is executed by the contract, privacy information can still be inferred by analyzing the transaction results, since states of the contract are publicly visible. In this paper, based on zero-knowledge proof and Hawk technology, a on-and-off-chain complete smart contract data feed privacy-preserving scheme is proposed. In order to present our scheme more intuitively, we combined the medical insurance compensation case to implement it, which is called MIPDF. In our MIPDF, the patient and the insurance company are parties involved in the contract, and the hospital is the data provider of data feed. The patient's medical data is sent to the smart contract under the umbrella of the zero-knowledge proof signature scheme. The smart contract verifies the proof and calculates the insurance premium based on the judgment logic. Meanwhile, we use Hawk technology to ensure the privacy of on-chain contract execution, so that no information will be disclosed due to the result of contract execution. We give a general description of our scheme within the Universal Composability (UC) framework. We experiment and evaluate MIPDF on Ethereum for in-depth analysis. The results show that our scheme can securely and efficiently support the functions of medical insurance and achieve complete privacy-preserving.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Investors now have a multitude of non-traditional assets to choose from, especially from the spectrum of alternative assets, such as financial digital assets. We start from the premise that there is a high risk associated with investing in financial digital assets, along with the opportunities presented from these emerging digital markets that evolve in a decentralized environment. We will be looking at the two major digital assets, specifically Bitcoin (BTC) and Ethereum (ETH), as per their dominance within the markets of crypto assets. This paper will focus on the evolution of financial digital assets and the impact on portfolio assessment that have allocations for BTC and ETH. In order to identify the value and potential of these financial digital assets, we will be addressing volatility and portfolio risks by means of a Vector Autoregression model on the returns of both, BTC and ETH.
The uncertainty due to the COVID-19 outbreak has encouraged investors to look for value hedging instruments to minimize risk, which can be in the form of hedging assets or safe-haven assets. In response to it, this study aims to find out whether Bitcoin, Ethereum, and gold can behave as hedging and safe-haven assets before and amid the pandemic in Indonesia. The strategy is by observing the effects of volatility and return of Bitcoin, Ethereum, and gold on the Indonesian stock market. This study employed both quantile regression and simple linear regression models on data of daily closing price taken before and during COVID-19. This study finds that they can be hedge and safe-haven assets during the COVID-19 pandemic in Indonesia. The findings show some significant correlations between assets that can help investors determine which assets can be hedging instruments.
This paper investigates the causality and cointegration relationships between seven major cryptocurrencies, namely Bitcoin (BTC), Binance Coin (BNB), Cardano (ADA), Dogecoin (DOGE), Ethereum (ETH), Polkadot (DOT) and Ripple (XRP), using Johansen Cointegration and Granger Causality tests over the period from August 21, 2020 to April 19, 2021. Results indicate that there exists cointegration among cryptocurrencies in the long run. Findings also show that there is a bi-directional causal relationship between BNB and ETH. Additionally, BNB appears to be Granger cause of ADA, DOGE and DOT. On the other hand, analyses provide evidence of one-way causality running from XRP to both DOGE and DOT. These results might have some important implications for investors in terms of portfolio management.
Traditional agricultural product traceability system adopts centralized storage, and the traceability process is solidified, which results in the low reliability of traceability results and the poor flexibility of the system. Aiming to solve this problem, blockchain technology is applied to supply chain traceability, and a supply chain traceability system based on sidechain technology is proposed. Goods management, information sharing, and product traceability in supply chain are realized through Ethereum smart contract. The sidechain technology is adopted to expand Ethereum so that it can meet the needs of practical applications. The experiment results show that the proposed system has a transaction function and information sharing function. Compared with similar trading systems, the proposed system has more advantages in throughput and security.
We introduce a model of greenhouse gas emissions due to on-chain activity on Ethereum, focusing on cryptoart. We also estimate the impact of individual transactions on the environment, both before and after the London hard fork. We find that with the current fee mechanism, spending one dollar on transaction fees corresponds to emitting at least the equivalent of 1.305 kilograms of CO2. We also describe several techniques to reduce cryptoart emissions, both in the short and long term.
Rico Nur Ilham, Isfenti Sadalia, Nisrul Irawati, Irada Sinta
<p><em>Cryptocurrency is an investment commodity that can generate returns and already has a license to be traded in exchange trading through the Indonesian Commodity Futures Trading Regulatory Agency (BAPEPTI). There are quite a lot of crypto digital assets traded in Indonesia through the trading company Indodax. The purpose of this research is focused on formulating a risk management process in cryptocurrency digital asset investment. In addition, from the results of this study, a policy recommendation known as LCTR or "Legal Cryptocurrency and Tax Revenue" is expected to be considered by the government in formulating policies on crypto digital assets so that the interests of all parties can be accommodated for the realization of maximum state revenue from commodity trading. crypto digital assets. This type of research is quantitative descriptive with the research population, namely 5 cryptocurrency coins with the largest market caps in Indonesia, namely Bitcoin, Ethereum, Ripple, Bitcoin Cash, Litecoin in Indonesia. The type of data in this study is time series data taken from March 2021 to December 2021 by conducting a documentation study conducted on the publication of monthly cryptocurrency transaction reports, so that a target population of 240 (4 years x 12 months x 5 coins) monthly report data is obtained. for the research sample. The data analysis method in this study used multiple linear regression and data analysis used statistical software e-views version 10. The output of this study was the publication of reputable international journals,</em><em></em></p><p> </p>
Blockchains and smart contracts are gaining momentum as enabling technologies for a wide set of applications where data distribution and sharing among decentralized infrastructures is required. In this work, we present a distributed application developed using blockchain technologies that allows individuals and health insurance organizations to come into agreement during the implementation of the healthcare insurance policies in each contract. For this purpose, health standards and semantic web technologies were used for the formal expression of both the insured individual's data and contract terms. Accordingly, a fine-grained data access policy was applied for evaluating contract terms on the basis of relevant data captured in healthcare settings. A prototype was implemented involving the development of several different smart contracts for the Ethereum platform as well as the necessary visual environment for accessing them. The developed system validates various features related to blockchain and smart contract features that are briefly discussed in this work, part of which can be mitigated or resolved through the use of a private permissioned blockchain. The application of well-established techniques for potential malfunctions of external services could also boost the security of the system and prevent it from potential attacks.
Due of transparency, decentralisation, and security qualities, Block chain is a cultural revalution which can be having significant process at current environment. For the process of its very first implementation of Crypto currencies, such as Bitcoin, Block chain has received a lot of attention. Distributed ledger system is designed for evolve at a rapid pace, conduct, and exchange information in future. Educators', corporate executives and scholars have recently been started to examine various elements of Ethereum in modern innovation. Among previous Chain polls that focus on the technology's deployments, difficulties, features, and protection. Researchers further give a comparison of frameworks, a categorization for compromise methods, and an examination on potential threats and unique experiences employed in the Block chain to date. Ultimately, the study discusses critical new approaches, unique application scenarios, and areas for further research that researchers might investigate in addition to making additional progress in this area.
In this paper, the distributed decentralized network with the nodes at any place can access the data behaviour intention performance is analysed and explained in detail. The bitcoin blockchain is elementary of several crypto-currencies. The blockchain technology holds principal assurance for a difference of enterprises, including financial services, cryptocurrency exchange, laundering of anti-money tracking system, unique identity security, healthcare, real estate, supply chain, and logistics monitoring. Results showed that blockchain is considerably new technology and the nodes are sharing their data in the network without any trust in other nodes. Furthermore, key aspects of using this technology, the users in the crypto world buy, sell, or exchange the crypto-coins in the blockchain network. Many of the protocols are there to exchange cryptocurrencies. The main contributions of this work liesbased on the protocol named uniswap protocol, which helps the users to exchange the crypto-coins. Uniswap protocol is defined to be the automated liquidity protocol provision on the blockchain Ethereum platform. With the uniswap, a user can buy or sell the ERC20 tokens in the decentralized distributed network by using an Ethereum smart contract. This paper will help the users in the blockchain network to useuniswap protocol as a trustworthy and efficient way of exchanging the crypto-coins or the tokens in the blockchain network.
Blockchain Technology Applications and Security
FinTech, Crowdfunding, Digital Finance
Advanced Steganography and Watermarking Techniques
Today, agriculture remains the most important economic activity in the world. Food care is a major concern for the whole society. For agriculture-based supply chain management, traceability is considered as the major requirement. Traceability helps in providing quality assurance and transparency to the end user. The antiquated traceability system has the complications of centralized systems, non-transparency of information, unpredictable data, and the very easy formation of false data. The World Health Organization (WHO) reports that one out of ten people is affected by having tainted food. Globalization involving different food production processes and automation pushes the food supply chain into a complicated web. Numerous advancements have been investigated lately to determine food vulnerability and carry productivity to food related issues. One of the expected advances is block chain, which is as of now being effectively executed in monetary areas, for example, bit coin. Block chain can also be used in the food supply chain industries to improve traceability and help in the danger decrease of fakes and different types of unlawful occupation. This paper presents a systematic survey on agrifood supply chain traceability issues using various block chain platforms such as Ethereum and Hyperledger, as well as IOT techniques such as barcodes, RFID, NFC, and QR codes. The performance of several consensus algorithms is also investigated.
This article examined how to work transactions that are stored in the digital ledgers are recorded in the Blockchain. It stores all the valuable data about the user's transactions. Results show that Blockchain has made the financial sector to great peak and got a good reputation among the people who thought it would not work well. By the use of cryptocurrency in the blockchain technology, the Ethereum market has more rise into the second-largest cryptocurrency platform in 2021. Furthermore, a key aspect of the user's gain on share markets as investments when its value goes peak. Due to a dilemma, in decentralized financial [Defi], Many of the users felt insecure while joining into the network. But after the use of transactions in the blockchain, Through serial investigational factor study, the recentlygrow scale was adapt to involve seven main characteristics of team-development intervention (i.e., Decentralization, immutability, transparency, persistency, auditability, security, and privacy). Many of the organizations came forward to implement blockchain technologies in the Ethereum platform to do the decentralized financial [Defi] exchanges. In this article, the theoretical and practical implications of building an application for financially exchanging the bitcoins (Crypto-coins) by using the compound protocol. This protocol makes our application highly secured and confidential in exchanging the Crypto-coins by following the rules.
Blockchain technology is gaining popularity day by day in every field. This technology has many advantages over traditional data storing approaches such as transparency, security, and immutability. This can be a boom in various healthcare applications. The core part of the technology is a smart contract which implies contract policies and conditions between two signing parties without any intermediary. In this chapter, a smart contract is proposed for the Healthcare system. Ethereum platform has been chosen for developing smart contracts. Remix Ethereum Integrated Development Environment (IDE) has been used for this purpose. Besides this, practical considerations have been addressed while building a smart contract. Further, the smart contract was tested for its functionality. Finally, optimization techniques have been applied to the developed smart contract to reduce the gas cost.