Youngbin Kim, Jun Gi Kim, Wook Kim, Jae Ho Im · 7 authors
This paper proposes a method to predict fluctuations in the prices of cryptocurrencies, which are increasingly used for online transactions worldwide. Little research has been conducted on predicting fluctuations in the price and number of transactions of a variety of cryptocurrencies. Moreover, the few methods proposed to predict fluctuation in currency prices are inefficient because they fail to take into account the differences in attributes between real currencies and cryptocurrencies. This paper analyzes user comments in online cryptocurrency communities to predict fluctuations in the prices of cryptocurrencies and the number of transactions. By focusing on three cryptocurrencies, each with a large market size and user base, this paper attempts to predict such fluctuations by using a simple and efficient method.
<em>Blockchain</em> technology has the capacity to make digital goods immutable, transparent, externally provable, decentralized, and distributed. Besides the initial experiment or data acquisition, all remaining parts of the research cycle could take place within a <em>blockchain system</em>. Attribution, data, data postprocessing, publication, research evaluation, incentivisation, and research fund distribution would thereby become comprehensible, open (at will) and provable to the external world. Currently, scientists must be trusted to provide a true and useful representation of their research results in their final publication; <em>blockchain</em> would make much larger parts of the research cycle open to scientific self-correction. This bears the potential to be a technical solution to the current reproducibility crisis in science, and could ‘reduce waste and make more research results true’.
A. B. Ackerman, Anne B. Chang, Nadia Diakun-Thibault, Luca Forni · 7 authors
The President’s Precision Medicine Initiative (PMI) is “enabling a new era of clinical care through research, technology, and policies that empower patients, researchers, and providers to work together toward the development of individualized care”. Its commitment to privacy and security in the setting of responsible data sharing and transparency is articulated in the “Privacy and Trust Principles” and the “Data Security Policy Principles and Framework”, developed by an interagency working groups including the Office of the National Coordinator for Health Information Technology in conjunction with multiple stakeholders.
In this paper, we review the threats to the security, confidentiality, integrity, and availability of PMI data. PMI organizations can mitigate these challenges through a new system architecture in development at MIT -- the OPAL/Enigma project -- which creates a peer-to-peer network that enables parties to jointly store and analyze data with complete privacy, based on highly optimized version of multi-party computation with a secret-sharing. An auditable, tamper-proof distributed ledger (a permissioned blockchain) records and controls access through smart contracts and digital identities. We conclude with an initial use case of OPAL/Enigma that could empower precision medicine clinical trials and research.
MIT’s OPAL/Enigma challenges traditional data security paradigms. Centralized databases cannot assure security and data integrity, regardless de-identification and controlled access requirements. Safe, vetted queries that are distributed to private, encrypted databases assure that organizations and participants can share health care data with cryptographic guarantees of privacy with various stakeholders, assuring momentum for a new era of medical research and practice.
This paper provides the analysis of the blockchain use in microgrids. The analysis is given from the hypothesis that with the help of IT instruments, self-governed decentralized organizations based on blockchain technology will take and perform public functions traditionally performed by central authorities and corporations in order to organize their relations within the microgrids.
Swarms of robots will revolutionize many industrial applications, from targeted material delivery to precision farming. However, several of the heterogeneous characteristics that make them ideal for certain future applications --- robot autonomy, decentralized control, collective emergent behavior, etc. --- hinder the evolution of the technology from academic institutions to real-world problems. Blockchain, an emerging technology originated in the Bitcoin field, demonstrates that by combining peer-to-peer networks with cryptographic algorithms a group of agents can reach an agreement on a particular state of affairs and record that agreement without the need for a controlling authority. The combination of blockchain with other distributed systems, such as robotic swarm systems, can provide the necessary capabilities to make robotic swarm operations more secure, autonomous, flexible and even profitable. This work explains how blockchain technology can provide innovative solutions to four emergent issues in the swarm robotics research field. New security, decision making, behavior differentiation and business models for swarm robotic systems are described by providing case scenarios and examples. Finally, limitations and possible future problems that arise from the combination of these two technologies are described.
Christopher D. Clack, Vikram A. Bakshi, Lee Braine
In this position paper, we consider some foundational topics regarding smart\ncontracts (such as terminology, automation, enforceability, and semantics) and\ndefine a smart contract as an automatable and enforceable agreement. We explore\na simple semantic framework for smart contracts, covering both operational and\nnon-operational aspects, and describe templates and agreements for\nlegally-enforceable smart contracts, based on legal documents. Building upon\nthe Ricardian Contract, we identify operational parameters in the legal\ndocuments and use these to connect legal agreements to standardised code. We\nalso explore the design landscape, including increasing sophistication of\nparameters, increasing use of common standardised code, and long-term research.\n
<p>The invention of the blockchain technology can be equated with the invention of the writing or Internet network, considering their major role in the communication between individuals as well as legal persons, regarding information transfer, money transfer etc. The authors analyse the technology, the implemented and projected examples of its use, its relationship with accounting and auditing as well as its influence on the development of these economic sciences.</p><p>The development of accounting and auditing is linked to the development of modern technologies. Nowadays, according to the technological progress the role of blockhain technology is constantly increasing. Blockhain is a distributed database that maintains a continuously-growing list of data records secured from tampering and revision. Blockchain can be used in financial and banking sectors first of all, but also in e-government and administrative sectors.</p>The implementation of blockchain technologies in accounting and auditing doesn’t change their fundamental principles but increases the auditing capacities. In some countries blockchain is adopted for auditing as a practical matter, including the national level.
The proliferation of Internet of Things (IoT) devices has transformed various sectors, improving efficiency and connectivity. However, this rise also significantly amplifies security vulnerabilities, exposing IoT ecosystems to various cyber threats. Traditional security mechanisms often fall short in addressing these vulnerabilities due to their centralized nature and scalability issues. Blockchain technology, recognized for its robust security features such as decentralization, transparency, and immutability, offers a promising alternative. This paper explores the application of advanced blockchain technologies, such as smart contracts, zero-knowledge proofs, and off-chain transactions, to enhance IoT security. Through theoretical analysis and empirical data, we demonstrate how blockchain can resolve critical security issues in IoT networks, including data integrity, device authentication, and secure communication. The findings suggest that integrating blockchain technology into IoT frameworks can significantly mitigate risks and bolster security. This research contributes to the academic discourse by highlighting practical implementations, challenges, and future perspectives on the convergence of blockchain and IoT technologies.
Pedro Moreno-Sánchez, Muhammad Bilal Zafar, Aniket Kate
Abstract The decentralized I owe you (IOU) transaction network Ripple is gaining prominence as a fast, low-cost and efficient method for performing same and cross-currency payments. Ripple keeps track of IOU credit its users have granted to their business partners or friends, and settles transactions between two connected Ripple wallets by appropriately changing credit values on the connecting paths. Similar to cryptocurrencies such as Bitcoin, while the ownership of the wallets is implicitly pseudonymous in Ripple, IOU credit links and transaction flows between wallets are publicly available in an online ledger. In this paper, we present the first thorough study that analyzes this globally visible log and characterizes the privacy issues with the current Ripple network. In particular, we define two novel heuristics and perform heuristic clustering to group wallets based on observations on the Ripple network graph. We then propose reidentification mechanisms to deanonymize the operators of those clusters and show how to reconstruct the financial activities of deanonymized Ripple wallets. Our analysis motivates the need for better privacy-preserving payment mechanisms for Ripple and characterizes the privacy challenges faced by the emerging credit networks.
Aggelos Kiayias, Ηλίας Κουτσουπιάς, Maria Kyropoulou, Yiannis Tselekounis
We study the strategic considerations of miners participating in the bitcoin's protocol. We formulate and study the stochastic game that underlies these strategic considerations. The miners collectively build a tree of blocks, and they are paid when they create a node (mine a block) which will end up in the path of the tree that is adopted by all. Since the miners can hide newly mined nodes, they play a game with incomplete information. Here we consider two simplified forms of this game in which the miners have complete information. In the simplest game the miners release every mined block immediately, but are strategic on which blocks to mine. In the second more complicated game, when a block is mined it is announced immediately, but it may not be released so that other miners cannot continue mining from it. A miner not only decides which blocks to mine, but also when to release blocks to other miners. In both games, we show that when the computational power of each miner is relatively small, their best response matches the expected behavior of the bitcoin designer. However, when the computational power of a miner is large, he deviates from the expected behavior, and other Nash equilibria arise.
A public ledger is a tamperproof sequence of data that can be read and augmented by everyone. Public ledgers have innumerable and compelling uses. They can secure, in plain sight, all kinds of transactions ---such as titles, sales, and payments--- in the exact order in which they occur. Public ledgers not only curb corruption, but also enable very sophisticated applications ---such as cryptocurrencies and smart contracts. They stand to revolutionize the way a democratic society operates. As currently implemented, however, they scale poorly and cannot achieve their potential. Algorand is a truly democratic and efficient way to implement a public ledger. Unlike prior implementations based on proof of work, it requires a negligible amount of computation, and generates a transaction history that will not "fork" with overwhelmingly high probability. Algorand is based on (a novel and super fast) message-passing Byzantine agreement. For concreteness, we shall describe Algorand only as a money platform.
Algorand is a truly decentralized, new, and secure way to manage a shared ledger. Unlike prior approaches based on {\em proof of work}, it requires a negligible amount of computation, and generates a transaction history that does not fork with overwhelmingly high probability. This approach cryptographically selects ---in a way that is provably immune from manipulations, unpredictable until the last minute, but ultimately universally clear--- a set of verifiers in charge of constructing a block of valid transactions. This approach applies to any way of implementing a shared ledger via a tamper-proof sequence of blocks, including traditional blockchains. This paper also presents more efficient alternatives to blockchains, which may be of independent interest.
Algorand significantly enhances all applications based on a public ledger: payments, smart contracts, stock settlement, etc. But, for concreteness, we shall describe it only as a money platform.
Saulo Ricci, Alex Borges, Helder Luiz, Daniel Sadoc Menasché · 5 authors
Apesar do crescente interesse em cripto moedas, tanto indústria quanto a academia sentem falta de análises quantitativas desses sistemas. Neste trabalho, caracterizamos o Bitcoin, um dos mais populares sistemas de cripto moedas, sob a ótica quantitativa. Visamos métricas importantes relacionadas a transações, como a probabilidade uma transação ser confirmada e o tempo decorrido para essa confirmação. Nossos resultados mostram que há um número não negligenciável de transações que não são confirmadas 24 horas após serem postadas na rede. Nesse caso, nós observamos uma alta correlação entre a taxa de uma transação, seu volume e a suspeita de que a transação não será confirmada. O trabalho mostra que transações do Bitcoin geralmente são confirmadas em períodos curtos, mas ainda assim, muito acima de tempos usuais de sistemas de cartão de crédito. Finalmente, nós provemos uma análise de nível de atividade simples, comparando um período importante na existência do sistema do Bitcoin –o fechamento do Silk Road– e um peróodo subsequente. Em resumo, concluimos que a rede Bitcoin se apresenta resiliente e não é dependente de hubs altamente centralizados.
Michele Amoretti, Giacomo Brambilla, Francesco Medioli, Francesco Zanichelli
Location-Based Services (LBSs) build upon geographic information to provide users with location-dependent functionalities. In such a context, it is particularly important that geographic locations claimed by users are trustworthy. Centralized verification approaches proposed in the last few years are not satisfactory, as they entail a high risk to the privacy of users. In this paper, we present and evaluate a novel decentralized, infrastructure-independent proof-of-location scheme based on blockchain technology. Our scheme guarantees both location trustworthiness and user privacy preservation.
Shayan Eskandari, Jeremy Clark, Abdelwahab Hamou-Lhadj
In this paper we discuss existing approaches for Bitcoin payments, as suitable for a small business for small-value transactions. We develop an evaluation framework utilizing security, usability, deployability criteria,, examine several existing systems, tools. Following a requirements engineering approach, we designed, implemented a new Point of Sale (PoS) system that satisfies an optimal set of criteria within our evaluation framework. Our open source system, Aunja PoS, has been deployed in a real world cafe since October 2014.
Jul 1, 2016·2016 Intl IEEE Conferences on Ubiquitous Intelligence & Computing, Advanced and Trusted Computing, Scalable Computing and Communications, Cloud and Big Data Computing, Internet of People, and Smart World Congress (UIC/ATC/ScalCom/CBDCom/IoP/SmartWorld)
Till Neudecker, Philipp Andelfinger, Hannes Hartenstein
Flooding Peer-to-Peer (P2P) networks form the basis of services such as the electronic currency system Bitcoin. The decentralized architecture enables robustness against failure. However, knowledge of the network's topology can allow adversaries to attack specific peers in order to, e.g., isolate certain peers or even partition the network. Knowledge of the topology might be gained by observing the flooding process, which is inherently possible in such networks,, performing a timing analysis on the observations. In this paper we present a timing analysis method that targets flooding P2P networks, show its theoretical, practical feasibility. A validation in the real-world Bitcoin network proves the possibility of inferring network links of actively participating peers with substantial precision, recall (both ~ 40%), potentially enabling attacks on the network. Additionally, we analyze the countermeasure of trickling, quantify the tradeoff between the effectiveness of the countermeasure, the expected performance penalty. The analysis shows that inappropriate parametrization can actually facilitate inference attacks.
Permisionless decentralized ledgers ("blockchains") such as the one underlying the cryptocurrency Bitcoin allow anonymous participants to maintain the ledger, while avoiding control or "censorship" by any single entity. In contrast, permissioned decentralized ledgers exploit real-world trust and accountability, allowing only explicitly authorized parties to maintain the ledger. Permissioned ledgers support more flexible governance and a wider choice of consensus mechanisms. Both kinds of decentralized ledgers may be susceptible to manipulation by participants who favor some transactions over others. The real-world accountability underlying permissioned ledgers provides an opportunity to impose fairness constraints that can be enforced by penalizing violators after-the- fact. To date, however, this opportunity has not been fully exploited, unnecessarily leaving participants latitude to manipulate outcomes undetectably. This paper draws attention to this issue, and proposes design principles to make such manipulation more difficult, as well as specific mechanisms to make it easier to detect when violations occur.
Luke Anderson, Ralph Holz, Alexander Ponomarev, Paul Rimba · 5 authors
Half a decade after Bitcoin became the first widely used cryptocurrency, blockchains are receiving considerable interest from industry and the research community. Modern blockchains feature services such as name registration and smart contracts. Some employ new forms of consensus, such as proof-of-stake instead of proof-of-work. However, these blockchains are so far relatively poorly investigated, despite the fact that they move considerable assets. In this paper, we explore three representative, modern blockchains---Ethereum, Namecoin, and Peercoin. Our focus is on the features that set them apart from the pure currency use case of Bitcoin. We investigate the blockchains' activity in terms of transactions and usage patterns, identifying some curiosities in the process. For Ethereum, we are mostly interested in the smart contract functionality it offers. We also carry out a brief analysis of issues that are introduced by negligent design of smart contracts. In the case of Namecoin, our focus is how the name registration is used and has developed over time. For Peercoin, we are interested in the use of proof-of-stake, as this consensus algorithm is poorly understood yet used to move considerable value. Finally, we relate the above to the fundamental characteristics of the underlying peer-to-peer networks. We present a crawler for Ethereum and give statistics on the network size. For Peercoin and Namecoin, we identify the relatively small size of the networks and the weak bootstrapping process.
Problem Explaining: Nowadays the financial system has been affected dramatically by the development in the era of information and communication technology. One of these phenomena, is Crypto Currency Bitcoin is the most famous among them. In the reviews of Crypto Currency and Bitcoin, we can pay special attention to the public opinion, because it can have a significant impact on the future of money. Purpose: The aim of this study is to identify the preferences of people using Bitcoin as a novel product introduced by human into the financial system. For this purpose, the important factors in choosing Bitcoin have been checked. In terms of practical purpose and collecting descriptive information, this research is survey - correlation. Design/methodology/approach: In this study the important factors in the selection of Bitcoin through the investigation of the opinions of experts and consumers, offering model by patterning the technology acceptance and innovation publication models, interviewing with experts using a questionnaire and the analysis of the model through PLS partial least square method using Version 2 SMARTPLS software. Findings: The results show that the variables of infrastructure, structural, individualistic and cultural factors through perceived value have a significant and positive impact on the intention of using people. Meanwhile cultural factor has had the largest share, but innovative, political and environmental factors haven’t had any significant effect. The results of this research indicate the effective factors in the users’ tendency to use Bitcoin. Originality/value: The main question in this research is that: Is there any significant relationship between the values perceived by the consumer from Bitcoin and the intention of using it?
Bitcoin is the most important and well known form of digital currency. It is not produced or backed by any single entity. Its production takes place in a decentralised manner and its value derives only from the fact that there is a growing community that attributes value to it and chooses to transact using this innovative means of payment. However, its importance is increasing, especially in the field of e-commerce. The main aim of this article is to examine the consumer’s right of withdrawal, as it is regulated in the Consumer Rights Directive (Directive 2011/83/EU), in case of payments with bitcoins. More specifically, it is examined whether a consumer’s payment with bitcoins can be a hindrance to the consumer’s protection, with respect to the withdrawal right provided by the aforementioned Directive in cases of distance and off-premises contracts. Furthermore, the consequences of the exercise of the withdrawal right are examined, particularly with regards to reimbursement. The main concerns derive from the bitcoin’s disputed legal nature and its high value volatility. Keywords Bitcoin Consumer Rights Directive consumer’s right of withdrawal e-commerce digital currency
Dominic Wörner, Thomas von Bomhard, Yan-Peter Schreier, Dominik Bilgeri
The Bitcoin ecosystem has grown tremendously in recent years.While the main sectors of growth and venture capital funding have been infrastructure for the Bitcoin ecosystem itself as well as financial services, there is also a more recent evolution in sectors beyond financial services.We classify the venture-capital backed start up ecosystem accordingly and present its evolution over time.Thereby, we identify interesting sectors, i.e. digital assets, marketplaces, and notary services.Each sector is further subdivided, and six representative venture-backed start-up companies are presented in comprehensive case studies.We extract the core innovations and Bitcoin features on which these are based.Finally, we critically discuss their disruptive potential.
Tendermint is a new protocol for ordering events in a distributed network under adversarial conditions. More commonly known as consensus or atomic broadcast, the problem has attracted significant attention recently due to the widespread success of digital currencies, such as Bitcoin and Ethereum, which successfully solve the problem in public settings without a central authority. Tendermint modernizes classic academic work on the subject to provide a secure consensus protocol with accountability guarantees, as well as an interface for building arbitrary applications above the consensus. Tendermint is high performance, achieving thousands of transactions per second on dozens of nodes distributed around the globe, with latencies of about one second, and performance degrading moderately in the face of adversarial attacks.