By deviating from an honest mining strategy, attackers can obtain additional rewards through mining attacks. Selfish mining is the most well-known mining attack. It includes selfish mining (SM1), ...optimal selfish mining (∊-optimal), and bribed selfish mining (BSM), etc. The mining models addressed in prior studies, however, are based on the Nakamoto consensus. Therefore, this paper proposes the ESM model (Selfish Mining under Ecological model). Our new model is fully compatible with fewer resource expenditure requirements. Meanwhile, we also describe a novel selfish mining attack that allows the malicious pool to gain additional revenue by using an ESM attack rather than SM1 when its power is less than 25%. Furthermore, we present an EBSM (Bribery Selfish Mining under Ecological) attack that combines ESM together with the bribery attack. As a result, under EBSM, the malicious solo miner has a chance to gain additional revenue. Finally, we undertake quantitative analyses and simulations to assess the effectiveness of our attacks.
There has been much debate about whether returns on financial assets, such as stock returns or commodity returns, are predictable; however, few studies have investigated cryptocurrency return ...predictability. In this article we examine whether bitcoin returns are predictable by a large set of bitcoin price-based technical indicators. Specifically, we construct a classification tree-based model for return prediction using 124 technical indicators. We provide evidence that the proposed model has strong out-of-sample predictive power for narrow ranges of daily returns on bitcoin. This finding indicates that using big data and technical analysis can help predict bitcoin returns that are hardly driven by fundamentals.
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.
Since the publication of Satoshi Nakamoto's white paper on Bitcoin in 2008, blockchain has (slowly) become one of the most frequently discussed methods for securing data storage and transfer through ...decentralized, trustless, peer-to-peer systems. This research identifies peer-reviewed literature that seeks to utilize blockchain for cyber security purposes and presents a systematic analysis of the most frequently adopted blockchain security applications. Our findings show that the Internet of Things (IoT) lends itself well to novel blockchain applications, as do networks and machine visualization, public-key cryptography, web applications, certification schemes and the secure storage of Personally Identifiable Information (PII). This timely systematic review also sheds light on future directions of research, education and practices in the blockchain and cyber security space, such as security of blockchain in IoT, security of blockchain for AI data, and sidechain security.
As a milestone in the development of outsourcing services, cloud computing enables an increasing number of individuals and enterprises to enjoy the most advanced services from outsourcing service ...providers. Because online payment and data security issues are involved in outsourcing services, the mutual distrust between users and service providers may severely impede the wide adoption of cloud computing. Nevertheless, most existing solutions only consider a specific type of services and rely on a trusted third-party to realize fair payment. In this paper, to realize secure and fair payment of outsourcing services in general without relying on any third-party, trusted or not, we introduce BPay, an outsourcing service fair payment framework based on blockchain in cloud computing. We first propose the system architecture, adversary model and design goals of BPay, then describe the design details. Our security and compatibility analysis indicates that BPay achieves soundness and robust fairness and it is compatible with the Bitcoin blockchain and the Ethereum blockchain. The key to the robust fairness and compatibility lies in an all-or-nothing checking-proof protocol and a top-down checking method. In addition, our experimental results show that BPay is computationally efficient. Finally, we present the applications of BPay in outsourcing services.
Some simple bitcoin economics Schilling, Linda; Uhlig, Harald
Journal of monetary economics,
October 2019, 2019-10-00, Letnik:
106
Journal Article
Recenzirano
Odprti dostop
•We provide a model of an endowment economy with two competing, but intrinsically worthless currencies (Dollar, Bitcoin) serving as medium of exchange.•We show a fundamental pricing equation, which ...in its simplest form implies that Bitcoin prices form a martingale.•“Mutual impatience” rules out Bitcoin speculation. Price volatility does not invalidate the medium-of-exchange function.•The Bitcoin block rewards are not a tax on Bitcoin holders: they are financed with a Dollar tax.•We discuss monetary policy implications, Bitcoin production via the proof-of-work competition, taxation of Bitcoin production, welfare implications and entry of new cryptocurrencies. We characterize the range of equilibria and provides specific examples.
We provide a model of an endowment economy with two competing, but intrinsically worthless currencies (Dollar, Bitcoin). Dollars are supplied by a central bank to achieve its inflation target, while the Bitcoin supply grows deterministically. Our fundamental pricing equation implies in its simplest form that Bitcoin prices form a martingale. “Mutual impatience” implies absence of speculation. Price volatility therefore does not invalidate the medium-of-exchange function. Bitcoin block rewards are not a tax on Bitcoin holders: they are financed with a Dollar tax. We discuss monetary policy implications, Bitcoin production, taxation, welfare and entry, and characterize the range of equilibria.
In recent years a new type of tradable assets appeared, generically known as cryptocurrencies. Among them, the most widespread is Bitcoin. Given its novelty, this paper investigates some statistical ...properties of the Bitcoin market. This study compares Bitcoin and standard currencies dynamics and focuses on the analysis of returns at different time scales. We test the presence of long memory in return time series from 2011 to 2017, using transaction data from one Bitcoin platform. We compute the Hurst exponent by means of the Detrended Fluctuation Analysis method, using a sliding window in order to measure long range dependence. We detect that Hurst exponents changes significantly during the first years of existence of Bitcoin, tending to stabilize in recent times. Additionally, multiscale analysis shows a similar behavior of the Hurst exponent, implying a self-similar process.
•We study statistical features and long-range dependence of Bitcoin returns.•Hurst exponent is computed for sliding windows.•Liquidity does not affect the level of long-range dependence.•Similar behavior of Hurst exponent at different time scales.
2022 has seen a significant decline in global cryptocurrency ratings, especially bitcoin. As it is known, one of the key components of the cryptocurrency’s cost is the amount of electrical energy ...spent by the computing equipment of the mining data centers. In the context of declining bitcoin rates, the management of the data centers’ energy costs becomes critical for maintaining the profitability and investment return of the mining projects. Russia is among the top-3 leading producers of cryptocurrencies, providing 11% of the global primary bitcoin transactions. In this regard, the management of the data centers’ costs related to the purchase of electricity in the Russian wholesale and retail electricity (capacity) markets presents a high scientific and practical importance. This article analyzes the pricing mechanisms for the purchase of electricity in Russia’s wholesale and retail electricity (capacity) markets on an industrial scale given the specifics of the hourly demand-based pricing. This paper suggests a new metrics system, including a capacity demand management coefficient and a transmission cost management coefficient, which allow setting specific price parameters for the different components of the electricity price based on demand analytics. Simulation of different parameters of the energy cost management in mining data centers demonstrated that the ultimate electricity price can, on average, be reduced by 70% of the initial level across all regions of the Siberian Federal District of Russia. The suggested energy cost management model takes into account both internal and external factors of industrial data centers as well as monitoring of their operations along with the price factors of the wholesale and retail electricity markets. This material may be useful to specialists in the field of management of mining data centers who are involved in the operation and/or design of such facilities across various regions of Russia.
The financial technology (FinTech) sector sees high potential value in cryptocurrency blockchain protocols, or distributed-ledger technology (DLT). However, the requirements and guarantees of ...blockchains for cryptocurrencies do not match those of FinTech-from transaction throughput to security primitives and privacy. The author explores how blockchain research beyond Bitcoin is closing these gaps and some of the challenges that remain.
•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.
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