Shaista Bibi, Shahid Hussain, Muhammad Imran Faisal
Cryptocurrency is one of the emerging online currency of the modern era. Big companies are investing in this technology. However, some established companies still hesitate to use it. According to them, it is a volatile trend which will fade up eventually. There is no such authority which will provide them feasibility information. So, investors can be helped by providing them feasibility information about locations for cryptocurrency investment around the world. This paper aims to provide the aforementioned information to the investors. The proposed methodology is based on Topic modeling along with public opinion mining about cryptocurrencies, blockchain network, bitcoin, litecoin, and ethereum. The crawled data for other cryptocurrencies are much insufficient, so that are excluded from the study. In the proposed methodology, the top locations where cryptocurrency is widely used are identified, then in that particular locations' users concerns along with their sentiment analyses are investigated. Top locations are identified such as Australia, Denmark, Netherlands, and the USA etc. Almost 83.7% tweets of Sweden show positive sentiment for cryptocurrency investment which ranks as the highest having friendly environment for cryptocurrency investment. Similarly, the UK shows the least positive perception of cryptocurrency and blockchain technology usage. Some of the noteworthy terms found are legitimacy, authorization rules, volatility, profit, investment, and fluctuations. Which describe the users' concerns/ interests' about cryptocurrency. Investors can focus on all these areas during business. These subtopics can help business experts to evolve their businesses' and to make them more sustainable on the basis of public perception.
Proof-of-burn has been used as a mechanism to destroy cryptocurrency in a verifiable manner. Despite its well known use, the mechanism has not been previously formally studied as a primitive. In this paper, we put forth the first cryptographic definition of what a proof-of-burn protocol is. It consists of two functions: First, a function which generates a cryptocurrency address. When a user sends money to this address, the money is irrevocably destroyed. Second, a verification function which checks that an address is really unspendable. We propose the following properties for burn protocols. Unspendability, which mandates that an address which verifies correctly as a burn address cannot be used for spending; binding, which allows associating metadata with a particular burn; and uncensorability, which mandates that a burn address is indistinguishable from a regular cryptocurrency address. Our definition captures all previously known proof-of-burn protocols. Next, we design a novel construction for burning which is simple and flexible, making it compatible with all existing popular cryptocurrencies. We prove our scheme is secure in the Random Oracle model. We explore the application of destroying value in a legacy cryptocurrency to bootstrap a new one. The user burns coins in the source blockchain and subsequently creates a proof-of-burn, a short string proving that the burn took place, which she then submits to the destination blockchain to be rewarded with a corresponding amount. The user can use a standard wallet to conduct the burn without requiring specialized software, making our scheme user friendly. We propose burn verification mechanisms with different security guarantees, noting that the target blockchain miners do not necessarily need to monitor the source blockchain. Finally, we implement the verification of Bitcoin burns as an Ethereum smart contract and experimentally measure that the gas costs needed for verification are as low as standard Bitcoin transaction fees, illustrating that our scheme is practical.
The world is slowly but surely going digital. Information is increasingly being stored digitally, and so are our personal information. The concept of digital identity is not a new one. It has been experimented with in various forms, such as in an employee portal. The use of mobile phones to access information is also a growing trend. Thus, it seems logical to combine the two to build digital identity on mobile. \n This project aims to develop an Android application to store and verify digital identity information. It uses the Ethereum blockchain to store digital identity documents and their associated keys in order to prevent tampering by a third party. The information being sent from one party to another is verified using the keys stored in the blockchain. All documents follow the formats proposed by the W3C Credentials Working Group, and this allows the format of the documents to be standardised and easily verifiable. Verification is done via digital signatures, which prevents unauthorised modification of the information while it are being sent or received. \n While the information is being transmitted, RSA encryption is used to preserve confidentiality. Only the sender and receiver will have the keys needed to decrypt the information. The receiver can then retrieve the public key specified in the credential from the Ethereum blockchain and use it to verify the information received. With the use of a public key infrastructure via the blockchain, and the secure storage and transmission of information via end-to-end encryption, information can be exchanged and verified securely. With this system in place, digital identities can be created, verified and used easily and safely.
N. Sai Sirisha, Tarasha Agarwal, Ranjeet Monde, Richa Yadav · 5 authors
The lack of transparency has made people lose trust in charities, making social funding stagnant. The donor is unaware of the legitimate utilization of his funds. Corruption adds to the distrust of the donor. This paper proposes a system called Charity-Chain that is a decentralised network built on the Ethereum blockchain. It helps social organisations to run projects transparently, using smart contract-based incentives to ensure their impact is independently verified and accessible to everyone. This makes it much easier for funders (philanthropic organisations, impact investors, small donors) to monitor their transactions and hence restore their trust in giving to such social organizations.
In Chapter 1 , I introduced Ethereum when I covered bitcoin, altcoins, and different consensus mechanisms. Specifically, I covered Ethereum’s PoW consensus and how utilizing Ethereum enables developers to create their own smart contracts and tokens. I mentioned that the Ethereum tokens can be generated as Ethereum requests for comment (ERCs) such as ERC-20, ERC-223, or ERC-777. In Chapter 3 , you created your own blockchain, and I covered bitcoin wallets and transactions.
We conduct a detailed analysis of investors in successful initial coin offerings (ICOs). The average ICO has 4700 contributors. The median participant contributes small amounts and many investors sell their tokens before the underlying product is developed. Large presale investors obtain tokens at a discount and flip part of their allocation shortly after the ICO. ICO contributors lack the protections traditionally afforded to investors in early-stage financing. Nevertheless, returns 9 months after the ICO are positive on average, driven mostly by an increase in the value of the Ethereum cryptocurrency.
Santiago Bragagnolo, Matteo Marra, Guillermo Polito, Elisa Gonzalez Boix
Analysing the blockchain is becoming more and more relevant for detecting attacks and frauds on cryptocurrency exchanges and smart contract activations. However, this is a challenging task due to the continuous growth of the blockchain. For example, in early 2017 Ethereum was estimated to contain approximately 300GB of data [1], a number that keeps growing day after day. In order to analyse such ever-growing amount of data, this paper argues that blockchain analysis should be treated as a novel type of application for Big Data platforms. In this paper we explore the application of parallelization techniques from the Big Data domain, in particular Map/Reduce, to extract and analyse information from the blockchain. We show that our approach significantly improves the index generation by 7.77 times, with a setup of 20 worker nodes, 1 Ethereum node and 1 Database node. We also share our findings of our massively parallel setup for querying Ethereum in terms of architecture and the bottlenecks. This should help researchers setup similar infrastructures for analysing the blockchain in the future.
Rishabh Mehta, Naman Kapoor, Soumya Sourav, Rajeev Shorey
In this paper, we aim to address the major problem of correct image attribution for photos being uploaded on the stock photo websites and peer-to-peer image sharing marketplaces, ensuring that original photographers are rightfully recognized and credited for their works. There are now millions of royalty-free images being shared every week on stock photo websites. There is a major discontent among photographers and graphics designers who share images on such websites regarding a widespread malpractice where others try to take credit for and benefit from original author's work. This happens when someone other than the original author uploads the same image as one already shared on the marketplace or uses image processing methods such as rotation, cropping, gray scale conversion etc and then uploads this tampered image to avoid copyright violation detection. To counter such problems, we propose a decentralised peer-to-peer photo sharing marketplace built on top of Ethereum test chain and demonstrate how it is fair, trustworthy and practical. Our decentralised application leverages perceptual hashes and robust smart contracts of Ethereum to automatically detect and reject tampered images that are perceptually similar to images already present on the marketplace. Due to inherent properties of Blockchain, our marketplace has no central authority controlling it, no third party interference, no single point of failure, zero-censorship and preserves online user privacy. To the best of our knowledge, this is the first work that provides a practical solution for automatically detecting and rejecting perceptually similar images on a decentralised image sharing platform, thus protecting the copyrights of genuine image authors.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
We explore the governance mechanisms of decentralized organization drawing on an empirical study of the open source blockchain project Ethereum. We identify three classes of governance mechanisms: control, coordination, and realignment, and compare governance praxis in centralized and decentralized organizations. The findings point to governing action through mutually affective processes between stakeholders and the organization as an emergent whole, in which we map articulations of governance to the process-ontological concepts code and territory. This informs a philosophical interpretation in which governing action is understood as both coding/decoding of norms and practices, and territorializing/deterritorializing of organizational boundaries through perceived shared notions of identity. We argue that interpretations of governance mechanisms in near-autonomous or stigmergic forms of a decentralized organization require a theoretical taxonomy emphasizing process over structure.
"Smart contracts...guarantee a very specific set of outcomes. There's never any confusion and there's never any need for litigation." ~JeffGarzik "If the blockchain promise comes to a reality...most goods, labor and capital will be allocated through decentralized global platforms. Disputes will certainly arise." ~ Clément Lesaege and Federico Ast Blockchain-based "smart" contracts may characterize much of the future of exchange as they expand the scope of potentially efficient bargains through restructuring and reducing transaction costs relative to traditional contracts. This Article analyzes the changes in transaction costs and execution efficiencies as contractual "distance"-the number of intermediaries required to make an exchange, weighted by the rational level of actual agreement between parties-increases between bespoke contracts, template contracts, contracts of adhesion, and algorithmic contracts housed on platforms like Ethereum and arbitrated on platforms such as Kleros. This framework shows that smart contracts have the potential to lower the contractual distance required to make an exchange by (1) overcoming trust issues that require intermediaries, (2) lowering the incentive to write certain kinds of boilerplate, and (3) increasing the incentive to understand contractual terms. As a result, wide implementation of smart contracts may return contract law closer to the legal ideal of mutual understanding as the basis for exchange. At the same time, these auto-executing agreements risk making the future of contract law a return to the era of sealed instruments, enforcing themselves regardless of impossibility, fraud, and other legal safeguards. As examples of these costs and benefits, the Article focuses on smart contracts in two industries: the environmental public goods sector and the film industry. These industries illustrate the potential for smart contracts as well as steps that can be taken to ensure that as code becomes law, it will retain the doctrinal wisdom applied to contracts before they became "smart."
Rui Song, Yubo Song, Ziming Liu, Min Tan · 5 authors
The birth of blockchain has promoted the development of electronic currencies such as Bitcoin and Ethereum. Blockchain builds a financial system based on cryptology instead of credit, which allows parties to complete the tran... | Find, read and cite all the research you need on Tech Science Press
In the previous chapter, you learned how to create your own private Ethereum test network so that you can try out the various Ethereum transactions, such as transferring Ethers to different accounts and performing mining. You also learned how to create accounts so that you can hold your own Ethers. In this chapter, you will learn how to use a Chrome extension known as the MetaMask. The MetaMask Chrome extension is an Ethereum wallet that allows you to hold your Ethereum account, and it will be an essential tool to help you develop and test Smart Contracts in the next few chapters.
We take this question to be isomorphic to, "What Keeps Fixed Exchange Rates Fixed?" and address it with analysis familiar in exchange-rate economics. Stablecoins solve the volatility problem by pegging to a national currency, typically the US dollar, and are used as vehicles for exchanging national currencies into non-stable cryptocurrencies, with some stablecoins having a ratio of trading volume to outstanding supply exceeding one daily. Using a rich dataset of signed trades and order books on multiple exchanges, we examine how peg-sustaining arbitrage stabilizes the price of the largest stablecoin, Tether. We find that stablecoin issuance, the closest analogue to central-bank intervention, plays only a limited role in stabilization, pointing instead to stabilizing forces on the demand side. Following Tether's introduction to the Ethereum blockchain in 2019, we find increased investor access to arbitrage trades, and a decline in arbitrage spreads from 70 to 30 basis points. We also pin down which fundamentals drive the two-sided distribution of peg-price deviations: Premiums are due to stablecoins' role as a safe haven, exhibiting, for example, premiums greater than 100 basis points during the COVID-19 crisis of March 2020; discounts derive from liquidity effects and collateral concerns.
This work presents ContractChecker, a Blockchain-based security protocol for verifying the storage consistency between the mutually distrusting cloud provider and clients. Unlike existing protocols, the ContractChecker uniquely delegates log auditing to the Blockchain, and has the advantages in reducing client cost and lowering requirements on client availability, lending itself to modern scenarios with mobile and web clients. The ContractChecker collects the logs from both clients and the cloud server, and verifies the consistency by cross-checking the logs. By this means, it does not only detects the attacks from malicious clients and server forging their logs, but also is able to mitigate those attacks and recover the system from them. In addition, we design new attacks against ContractChecker exploiting various limits in real Blockchain systems (e.g., write unavailability, Blockchain forks, contract race conditions). We analyze and harden the security of ContractChecker protocols against the proposed new attacks. For evaluating the cost, we build a functional prototype of the ContractChecker on Ethereum/Solidity. By experiments on private and public Ethereum testnets, we extensively evaluate the cost of the ContractChecker in comparison with that of existing client-based log auditing works. The result shows the ContractChecker can scale to hundreds of clients and save client costs by more than one order of magnitude.
Cryptocurrencies have emerged about ten years ago as a new form of currency and have attracted much attention since they depend on a fully decentralized system, and so their transactions are very fast and have zero transaction cost. Therefore, character of cryptocurrencies and their volatility have been discussed widely by investors, policymakers and economists in recent years. From this point of view, this study aims to explain the price volatility of cryptocurrencies with macro-financial indicators, and thereby, the effects of S&P 500 stock market index, gold price, oil price, 2-year benchmark US Bond interest rate and US Dollar index on the prices of four major cryptocurrencies, Bitcoin, Litecoin, Ethereum, and Ripple, are investigated. The study comprises a panel data analysis applied to daily data over the period of August 2016 – April 2019, and analysis results show that increases in gold price, oil price and S&P 500 index raise the prices of cryptocurrencies, while increases in 2-year benchmark US Bond interest rate and US Dollar index cause to a fall. This adverse effects of the US Dollar index and US Bond interest rate on the prices of cryptocurrencies indicates that when the value of US Dollar and US Bond yield decrease investors prefer to invest in cryptocurrencies as alternative investment instruments. On the other hand, cryptocurrencies move with a similar trend of stock market index, gold price and oil price which are overall market indicators. Thereby, findings of this study show that cryptocurrencies behave more like an investment instrument than a currency, and prices of these financial assets interact with significant macro-financial indicators.