Thach Ngoc Nguyen, Christian Servín, Владик Крейнович
Nowadays, most financial transactions are based on a centralized system, when all the transaction records are stored in a central location. This centralization makes the financial system vulnerable to cyber-attacks. A natural way to make the financial system more robust and less vulnerable is to switch to decentralized currencies. Such a transition will also make financial system more transparent. Historically first currency of this type -- bitcoin -- use a large amount of electric energy to mine new coins and is, thus, not scalable to the level of financial system as a whole. A more realistic and less energy-consuming scheme is provided by proof-of-stake currencies, where the right to mint a new coin is assigned to a randomly selected user, with probability depending of the user's stake (e.g., his/her number of coins). What probabilities should we choose? In this paper, we find the probability selection that provides the optimal result -- optimal in the sense that it is the least inductive to cheating.
Nikos Fotiou, Vasilios A. Siris, George C. Polyzos
Despite technological advances, most smart objects in the Internet of Things (IoT) cannot be accessed using technologies designed and developed for interacting with powerful Internet servers. IoT use cases involve devices that not only have limited resources, but also they are not always connected to the Internet and are physically exposed to tampering. In this paper, we describe the design, development, and evaluation of a smart contract-based solution that allows end-users to securely interact with smart devices. Our approach enables access control, Thing authentication, and payments in a fully decentralized setting, taking at the same time into consideration the limitations and constraints imposed by both blockchain technologies and the IoT paradigm. Our prototype implementation is based on existing technologies, i.e., Ethereum smart contracts, which makes it realistic and fundamentally secure.
A treasury system is a community-controlled and decentralized collaborative decision-making mechanism for sustainable funding of blockchain development and maintenance. During each treasury period, project proposals are submitted, discussed, and voted for; top-ranked projects are funded from the treasury. The Dash governance system is a real-world example of such kind of systems. In this work, we, for the first time, provide a rigorous study of the treasury system. We modelled, designed, and implemented a provably secure treasury system that is compatible with most existing blockchain infrastructures, such as Bitcoin, Ethereum, etc. More specifically, the proposed treasury system supports liquid democracy/delegative voting for better collaborative intelligence. Namely, the stake holders can either vote directly on the proposed projects or delegate their votes to experts. Its core component is a distributed universally composable secure end-to-end verifiable voting protocol. The integrity of the treasury voting decisions is guaranteed even when all the voting committee members are corrupted. To further improve efficiency, we proposed the world's first honest verifier zero-knowledge proof for unit vector encryption with logarithmic size communication. This partial result may be of independent interest to other cryptographic protocols. A pilot system is implemented in Scala over the Scorex 2.0 framework, and its benchmark results indicate that the proposed system can support tens of thousands of treasury participants with high efficiency.
The purpose of this study is to develop robust estimation of association between two types of crypto-currencies namely Bitcoin and Ethereum. Daily data of crypto-currencies are collected from https://coinmarketcap.com. The period for data analysis is started from January 2017 until October 2018. The value of mean return for Bitcoin is 13.18 %. Meanwhile, the value of mean return for Ethereum is 27.85 %. The standard deviation for Bitcoin is 30.27 % and Ethereum is 64.24 %. Then, this study performed Person product moment coefficient analysis to evaluate the correlation between these two crypto-currencies. Result indicates the association coefficient value is 0.50. The correlation shows there is strong positive correlation between Bitcoin return and Ethereum return. As conclusion, there is significant relationship between Bitcoin and Ethereum return data with strong positive correlation (r = 0.503, n = 21, p =0.020).The significant of this study is to help investors to make better decision in selecting appropriate investment portfolio for their investment fund that contributes better return and lower risk.
Phan The Duy, Do Thi Thu Hien, Do Hoang Hien, Van-Hau Pham
In the "Industry 4.0" era, blockchain as well as related distributed ledger technologies has been an unmissable trend for both academy and industry recently. Blockchain technology has become famous as the innovative technology that underlies cryptocurrencies such as Bitcoin and Ethereum platform. It also has been spreading with multiple industries exploring their capabilities and new blockchain use cases springing up on a daily basis. Its emergence has brought a great deal of impact on how the information will be stored and processed securely. Furthermore, almost of advocates say that blockchain will disrupt and change everything from education to financial payments, insurance, intellectual property, healthcare,... in the years to come. However, a comprehensive survey on potential and issues of blockchain adoption in academy and industry has not been yet accomplished. This paper tries to conduct a comprehensive survey on the blockchain technology adoption by discussing its influences as well as the opportunities and challenges when utilizing it in the real-world scenarios.
In this paper, we present a prototype of multi-user system for access control to datasets stored in an untrusted cloud environment. Cloud storage like any other untrusted environment needs the ability to secure share information. Our approach provides an access control over the data stored in the cloud without the provider participation. The main tool of access control mechanism is ciphertext-policy attribute-based encryption scheme with dynamic attributes. Using a blockchain-based decentralized ledger, our system provides immutable log of all meaningful security events, such as key generation, access policy assignment, change or revocation, access request. We propose a set of cryptographic protocols ensuring privacy of cryptographic operations requiring secret or private keys. Only ciphertexts of hash codes are transferred through the blockchain ledger. The prototype of our system is implemented using smart contracts and tested on Ethereum blockchain platform.
The advancements of AI techniques and its transformation made an intelligent automated process using Internet of Things (IoT), machine optimization in various industrial applications. One of the notable change happens in the healthcare industry witnessed significant progress, leading to the emergence of Health 4.0. This new era encompasses a wide range of cutting-edge technologies including the Internet of Things (IoT), Internet of Services (IoS), Medical Cyber-Physical Systems (CPS), Health Cloud, Health Fog etc. The largest barrier to electronic healthcare is securing all medical equipment that are connected to the internet. Blockchain, a distributed and immutable ledger or database, has gained popularity across various sectors, including healthcare, due to its efficiency and reliability by offering features such as decentralization, enhanced security, and immutability. This chapter aims to explore the advantages and challenges associated with implementing blockchain technology in healthcare 4.0 by providing factual evaluation of block chain's progress in healthcare.
Kuo‐Hui Yeh, Chunhua Su, Jia-Li Hou, Wayne Chiu · 5 authors
Recently, the popularity and universality of smart-devices has led to rapid advancement in the development of applications for mobile commerce around the world. Novel mobile payment schemes, such as Apple pay, Android pay, and Samsung pay are becoming an increasingly popular ways to conduct online transactions, no matter what type of smart devices are used. Due to the attendant growth in the importance of security, significant attention has been devoted to the challenge of designing and implementing a robust mobile payment scheme for securing online transactions. In this paper, we demonstrate a robust mobile payment scheme based on sturdy certificateless signatures with bilinear pairing. We elegantly refine the proposed mobile payment scheme to make it suitable for computation-constrained mobile devices. The practicability of the proposed mobile payment scheme is then certified via a rigorous security analysis and thorough performance evaluation using the Raspberry PI as the implementation platform for our proposed scheme. Furthermore, we implement a transaction repository with the aid of smart contract technology. The simulation results, based on Ethereum, demonstrate the feasibility of employing the smart contract technology to secure mobile payments.
In a world full of new technology, the risk of fraud is constantly increasing. In the securities industry, this risk existed long before the use of technology. Congress enacted the Securities Act of 1933 to combat the risk of fraud and misrepresentation in the sale of securities. By requiring full disclosure, investors have the opportunity to make informed decisions prior to investing. However, Distributed Autonomous Organizations (“DAOs”), through the use of blockchains and smart-contracts, engage in the sale of securities without fully disclosing the risks or complying with the registration requirements of the Securities Act of 1933. Compliance with the burdensome requirements of registration, however, would destroy this new technology and method of conducting business. To avoid this set-back, Congress must amend the registration requirements to provide an exemption for DAOs. This exemption, although reducing current registration burdens, must still require DAOs to disclose certain information, thereby ensuring investors are informed prior to investing. Furthermore, due to the unique nature of the blockchain, smartcontract, and DAOs, Congress must impose a fiduciary duty on the creators of DAOs to ensure compliance with the disclosure requirements. Further, Congress should consider the allowance of burden-shifting following the initial crowdsale.
Sina Rafati Niya, Florian Schüpfer, Thomas Bocek, Burkhard Stiller
Abstract This work introduces the design and implementation of an Android-based Peer-to-peer Purchase and Rental Application termed PuRSCA, which leverages Smart Contracts (SC) and the Ethereum public blockchain (BC). As a Device-to-device (D2D) communication protocol, WiFi-Direct is chosen to enable the P2P data transmission between two parties. This work results in a cost-efficient, secure, SC-based, P2P, and Decentralized application (Dapp). Evaluations on performance of this Dapp is specified in terms of its D2D deployment, transaction costs, scalability, security, and privacy.
Shaun Azzopardi, Gordon J. Pace, Fernando Schapachnik
Smart contracts have been proposed as executable implementations enforcing real-life contracts. Unfortunately, the semantic gap between these allows for the smart contract to diverge from its intended deontic behaviour. In this paper we show how a deontic contract can be used for real-time monitoring of smart contracts specifically and request-based interactive systems in general, allowing for the identification of any violations. The deontic logic of actions we present takes into account the possibility of action failure (which we can observe in smart contracts), allowing us to consider novel monitorable semantics for deontic norms. For example, taking a rights-based view of permissions allows us to detect the violation of a permission when a permitted action is not allowed to succeed. A case study is presented showing this approach in action for Ethereum smart contracts.
Nowadays cutting-edge technologies such as machine learning, analytics, artificial intelligence, the cloud, and the blockchain are entering the marketplace at an unprecedented speed. The blockchain is one of the forerunners among them and is considered to be the next tech disruptor. According to a survey by the World Economic Forum, 10 percent of the global GDP will be relying on blockchain-based technology by 2027.
With the explosive growth in cryptocurrencies over the last couple of years, the cost of mining these technologies (the process through which users devote CPU power to operate the underlying blockchains) have similarly exploded. This paper examines one overarching question regarding this issue â what factor or factors explain the geographic distribution of cryptocurrency nodes (mining operations) across the world? In exploring this question, this research considers electricity price, internet access, Tor network relays, and others. Using node distribution data for Bitcoin and Ethereum â the two largest cryptocurrencies â this paper analyzes cross-sectional and panel data regression models, and establishes that electricity price has not played a significant role in this distribution up to this point, and concludes that the historical association between Tor relays and Bitcoin use has had a much greater impact. Lastly, this paper discusses the broader implications of its findings, and the potential areas of research for further understanding of this field.