Bitcoin is an emerging crypto-currency, which is wrapped in mystery and controversy. The goal is to transform how we transfer payments. The current approach for sending money from one remote party to another is via bank deposit and transfer by check or bank transfer. PayPal and other services were developed to provide faster payments to verified individuals, but each layer in the transaction adds time, cost, and/or risk to the transaction. Users of this new digital currency proclaim the benefits of security, anonymity, and efficiency for making transactions. The functionality and structure of the Bitcoin Network is complex and often attacked for not being a suitable replacement for currency. An independent understanding can be developed of the composite Bitcoin Financial Systems of Systems architecture by considering the challenges any System of System would face. A functional analysis, employing the Systems Modeling Language (SysML), is performed on the Bitcoin System of Systems architecture to help gain an understanding of the structure and functionality, and how that relates to the key actors and use cases, for determining if the users’ expectations are aligned with the architecture.
We propose a high level network architecture for an economic system that integrates money, governance and reputation. We introduce a method for issuing, and redeeming a digital coin using a mechanism to create a sustainable global economy and a free market. To maintain a currency's value over time, and therefore be money proper, we claim it must be issued by the buyer and backed for value by the seller, exchanging the products of labour, in a free market. We also claim that a free market and sustainable economy cannot be maintained using economically arbitrary creation and allocation of money. Nakamoto, with Bitcoin, introduced a new technology called the cryptographic blockchain to operate a decentralised and distributed accounts ledger without the need for an untrusted third party. This blockchain technology creates and allocates new digital currency as a reward for "proof-of-work", to secure the network. However, no currency, digital or otherwise, has solved how to create and allocate money in an economically non-arbitrary way, or how to govern and trust a world-scale free enterprise money system. We propose an "Ontologically Networked Exchange" (ONE), with purpose as its highest order domain. Each purpose is defined in a contract, and the entire economy of contracts is structured in a unified ontology. We claim to secure the ONE network using economically non-arbitrary methodologies and economically incented human behaviour. Decisions influenced by reputation help to secure the network without an untrusted third party. The stack of contracts, organised in a unified ontology, functions as a super recursive algorithm, with individual use programming the algorithm, acting as the "oracle". The state of the algorithm becomes the "memory" of a scalable and trustable artificial intelligence (AI). This AI offers a new platform for what we call the "Autonomy-of-Things" (AoT).
Bitcoin (BTC) is a major virtual currency. Using weekly data over the 2010-2013 period, we analyze a BTC investment from the standpoint of a US investor with a diversified portfolio including both traditional assets (worldwide stocks, bonds, hard currencies) and alternative investments (commodities, hedge funds, real estate). Over the period under consideration, BTC investment had highly distinctive features, including exceptionally high average return and volatility. Its correlation with other assets was remarkably low. Spanning tests confirm that BTC investment offers significant diversification benefits. We show that the inclusion of even a small proportion of BTCs may dramatically improve the risk-return trade-off of well-diversified portfolios. Results should however be taken with caution as the data may reflect early-stage behavior that may not last in the medium or long run.
Feng Mai, Qing Bai, Zhe Shan, Xin Wang · 5 authors
Bitcoin’s emergence has the potential to pave the way for a technological revolution in financial markets. What determines its valuation is an important open question with far-reaching business and policy implications. Building on Information Systems and Finance literature, we examine the dynamic interactions between social media and the monetary value of Bitcoin using textual analysis and vector error correction models. We show that more bullish forum posts are associated with higher future Bitcoin values. Interestingly, social media’s effects on Bitcoin are driven primarily by the silent majority, the 95% of users who are less active and whose contributions amount to less than 40% of total messages. In addition, messages on an Internet forum, relative to tweets, have a stronger impact on future Bitcoin value. Overall, our findings reveal that social media sentiment is an important predictor in determining Bitcoin’s valuation, but not all social media messages are of equal impact. This study offers new insights into the digital currency market and the economic impact of social media.
The advent of Bitcoin in 2009 has not only introduced Cryptocurrencies and lead to a new digitization movement in the financial, especially payments industry but also made way for a new breed of innovative technologies based on decentralized digital currencies. Generally, decentralized consensus systems could change the very nature of how companies, organizations and individuals are built and interact with each other. Decentralized consensus systems, decentralized applications and smart contracts provide the conceptual framework as well as the technological basis to establish predefined, incorruptible protocols and contracts to organize human behavior and interconnectedness. However, the technical protocols and implementations are quite complex and practitioners as well as interdisciplinary researchers not familiar with cryptography, network protocols or decentralized networks are struggling to find access to these concepts and grasp their potential. To fill this gap, we develop a comprehensive taxonomy of decentralized consensus systems in order to provide a tool for researchers and practitioners alike to facilitate classification and analysis of emerging technologies in the field of "Crypto 2.0", the next level of innovation beyond cryptocurrencies.
PGP is built upon a Distributed Web of Trust in which the trustworthiness of a user is established by others who can vouch through a digital signature for that particular identity. Preventing its wholesale adoption are a number of inherent weaknesses to include (but not limited to) the following: 1) Trust Relationships are built on a subjective honor system, 2) Only first degree relationships can be fully trusted, 3) Levels of trust are difficult to quantify with actual values, and 4) Issues with the Web of Trust itself (Certification and Endorsement). Although the security that PGP provides is proven to be reliable, it has largely failed to garner large scale adoption. In this paper, we propose several novel contributions to address the aforementioned issues with PGP and associated Web of Trust. To address the subjectivity of the Web of Trust, we provide a new certificate format based on Bitcoin which allows a user to verify a PGP certificate using Bitcoin identity-verification transactions - forming first degree trust relationships that are tied to actual values (i.e., number of Bitcoins transferred during transaction). Secondly, we present the design of a novel Distributed PGP key server that leverages the Bitcoin transaction blockchain to store and retrieve Bitcoin-Based PGP certificates. Lastly, we provide a web prototype application that demonstrates several of these capabilities in an actual environment.
Shayan Eskandari, David Barrera, Elizabeth Stobert, Jeremy Clark
Bitcoin users are directly or indirectly forced to deal with public key cryptography, which has a number of security and usability challenges that differ from the password-based authentication underlying most online banking services. Users must ensure that keys are simultaneously accessible, resistant to digital theft and resilient to loss. In this paper, we contribute an evaluation framework for comparing Bitcoin key management approaches, and conduct a broad usability evaluation of six representative Bitcoin clients. We find that Bitcoin shares many of the fundamental challenges of key management known from other domains, but that Bitcoin may present a unique opportunity to rethink key management for end users.
Open access
3 source records
User Authentication and Security Systems
Advanced Steganography and Watermarking Techniques
Journal of Anthropology and Archaeology is a peer-reviewed international journal, which publishes original papers promoting theoretical, methodological and empirical developments in the discipline of socio-cultural anthropology.
In spite of the fact that a lot of virtual currencies have been created in recent years, bitcoin is the best known from all of them and regularly reported in the news. Currency without identified creator is appreciated by its user for non-centralized running, without any chance of governments to influence the money supply. The advantages of bitcoin, such as very quick payments worldwide, stop of inflations caused by governments trying to solve their own problems or high level of transactions privacy are widely mentioned. The aim of the article is not to describe the technical issue of bitcoin and explain how this system works, because it has been widely explained in other articles. The aim is focusing on economic aspects of bitcoin, the technical aspects are mentioned only if necessary. For accomplishing the aim the article is split in two parts. The first part is dedicated to answering the question “What is bitcoin?”. It examines whether bitcoin complies with theoretical, empirical and law definition of money. The law definition of money compliance is done for Czech, German and EU law in general, but attitudes of US and Chinese governments are also mentioned. According to the findings, bitcoin cannot be easily considered as money. The second part is focused on store of value money function. Better store of value in comparison with fiat currencies should be important advantage of bitcoin. This function examination is based on volatility calculation for bitcoin and other currencies and assets. Comparing of results shows that volatility (and therefore risk) of bitcoin is significantly higher than of other currencies and assets.
Several new services incentivize clients to compete in solving large computation tasks in exchange for financial rewards. This model of competitive distributed computation enables every user connected to the Internet to participate in a game in which he splits his computational power among a set of competing pools — the game is called a computational power splitting game. We formally model this game and show its utility in analyzing the security of pool protocols that dictate how financial rewards are shared among the members of a pool. As a case study, we analyze the Bitcoin cryptocurrency which attracts computing power roughly equivalent to billions of desktop machines, over 70% of which is organized into public pools. We show that existing pool reward sharing protocols are insecure in our game-theoretic analysis under an attack strategy called the “block withholding attack”. This attack is a topic of debate, initially thought to be ill-incentivized in today’s pool protocols: i.e., causing a net loss to the attacker, and later argued to be always profitable. Our analysis shows that the attack is always well-incentivized in the long-run, but may not be so for a short duration. This implies that existing pool protocols are insecure, and if the attack is conducted systematically, Bitcoin pools could lose millions of dollars worth in months. The equilibrium state is a mixed strategy—that is—in equilibrium all clients are incentivized to probabilistically attack to maximize their payoffs rather than participate honestly. As a result, a part of the Bitcoin network is incentivized to waste resource competing for higher selfish reward.
Ifigeneia Georgoula, Demitrios E. Pournarakis, Christos Bilanakos, Dionisios N. Sotiropoulos · 5 authors
This paper uses time-series analysis to study the relationship between Bitcoin prices and fundamental economic variables, technological factors and measurements of collective mood derived from Twitter feeds. Sentiment analysis has been performed on a daily basis through the utilization of a state-of-the-art machine learning algorithm, namely Support Vector Machines (SVMs). A series of short-run regressions shows that the Twitter sentiment ratio is positively correlated with Bitcoin prices. The short-run analysis also reveals that the number of Wikipedia search queries (showing the degree of public interest in Bitcoins) and the hash rate (measuring the mining difficulty) have a positive effect on the price of Bitcoins. On the contrary, the value of Bitcoins is negatively affected by the exchange rate between the USD and the euro (which represents the general level of prices). A vector error-correction model is used to investigate the existence of long-term relationships between cointegrated variables. This kind of long-run analysis reveals that the Bitcoin price is positively associated with the number of Bitcoins in circulation (representing the total stock of money supply) and negatively associated with the Standard and Poor's 500 stock market index (which indicates the general state of the global economy).
The buzz surrounding Bitcoin has reached a fever pitch. Yet in academic legal discussions, disproportionate emphasis is placed on bitcoins (that is, virtual currency), and little mention is made of blockchain technology—the true innovation behind the Bitcoin protocol. Simply, blockchain technology solves an elusive networking problem by enabling “trustless” transactions: value exchanges over computer networks that can be verified, monitored, and enforced without central institutions (for example, banks). This has broad implications for how we transact over electronic networks. This Note integrates current research from leading computer scientists and cryptographers to elevate the legal community’s understanding of blockchain technology and, ultimately, to inform policymakers and practitioners as they consider different regulatory schemes. An examination of the economic properties of a blockchain-based currency suggests the technology’s true value lies in its potential to facilitate more efficient digital-asset transfers. For example, applications of special interest to the legal community include more efficient document and authorship verification, title transfers, and contract enforcement. Though a regulatory patchwork around virtual currencies has begun to form, its careful analysis reveals much uncertainty with respect to these alternative applications.
In this paper, I propose a new concept for understanding the role of algorithms in daily life: algorithmic authority. Algorithmic authority is the legitimate power of algorithms to direct human action and to impact which information is considered true. I use this concept to examine the culture of users of Bitcoin, a crypto-currency and payment platform. Through Bitcoin, I explore what it means to trust in algorithmic authority. My study of the Bitcoin community utilizes interview and survey data. I found that Bitcoin users prefer algorithmic authority to the authority of conventional institutions which they see as untrustworthy. However, I argue that Bitcoin users do not have blind faith in algorithms; rather, they acknowledge the need for mediating algorithmic authority with human judgment. I examine the tension between members of the Bitcoin community who would prefer to integrate Bitcoin with existing institutions and those who would prefer to resist integration.