Blockchain Papers

Pedro Jorge Melgo Vieira

No abstract is available for this record.

James Nicholson

This article considers Bitcoin as a system of exchange, and the block chain technology it is built on, in the context of supporting developing nations. If integrated correctly Bitcoin could have far reaching applications, from tackling corruption to empowering women. This article found Bitcoin to be a feasible option, with support from real world applications and global endorsement from users. The discussion is then applied in the context of corruption as it puts forward this emerging technology as an alternative to traditional centralised fiscal systems. The article posits that public libraries could be potential facilitators and a crucial component of this integration.

Christopher Cordi

Payment channels secured with cryptocurrency as collateral enable users to make many transactions with few blockchain broadcasts. Networks of payment channels have emerged as a proposed solution to Bitcoin’s scaling problem. Since the proposal of the first payment channel network, the Lightning Network, alternatives promising significant improvements, such as the Sprites protocol, have been proposed. Without at-scale implementations to analyze in situ, it is difficult to make meaningful comparisons of payment channel network protocols. In order to bridge this gap, we introduce a new simulation framework that can be used to evaluate how different payment channel network protocols will perform in both the expected and worst cases. 
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\nOur framework is generic and accommodates benchmarking across different variants of payment channel network protocols, network topologies, routing algorithms, and user behaviors. User spending behavior in our payment channel network simulator is generated based on behavioral modeling techniques used in credit card fraud research. Our simulation is the first payment channel network simulator to seed user behaviors with data from real-world credit card users. 
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\nOur framework can be used to evaluate expected case performance and resiliency to attacks across different payment channel network protocols and routing algorithms. We demonstrate the utility of our framework through comparisons of the Lightning Network to Sprites. We also compare the proposed decentralized routing algorithm, Flare, to an ideal centralized routing algorithm. Our results reveal that if spending behaviors are similar to those of credit card users, scale-free network topologies achieve higher throughput and resiliency compared to small-world networks. We also confirm that the Sprites protocol enjoys numerous advantages over the Lightning Network including smaller durations, shorter path length payments, and greater resiliency, all of which are most significant in decentralized topologies using decentralized routing algorithms.

Zehui Xiong, Yang Zhang, Dusit Niyato, Ping Wang · 5 authors

Blockchain, as the backbone technology of the current popular Bitcoin digital currency, has become a promising decentralized approach for resource and transaction management. Although blockchain has been widely adopted in many applications, e.g., finance, healthcare, and logistics, its application in mobile environments is still limited. This is due to the fact that blockchain users need to solve preset proof-of-work puzzles to add new transactions to the blockchain. Solving the proof-of-work, however, consumes substantial resources in terms of CPU time and energy, which is not suitable for resource-limited mobile devices. To facilitate blockchain applications in future mobile Internet of Things systems, multiple access mobile edge computing appears to be an auspicious option to solve the proof-of-work puzzles for mobile users. We first introduce a novel concept of edge computing for mobile blockchain. Then, we introduce an economic approach for edge computing resource management. Moreover, a demonstrative prototype of mobile edge computing enabled blockchain systems is presented with experimental results to justify the proposed concept.

Zehui Xiong, Yang Zhang, Dusit Niyato, Ping Wang · 5 authors

Blockchain, as the backbone technology of the current popular Bitcoin digital currency, has become a promising decentralized data management framework. Although blockchain has been widely adopted in many applications (e.g., finance, healthcare, and logistics), its application in mobile services is still limited. This is due to the fact that blockchain users need to solve preset proof-of-work puzzles to add new data (i.e., a block) to the blockchain. Solving the proof of work, however, consumes substantial resources in terms of CPU time and energy, which is not suitable for resource-limited mobile devices. To facilitate blockchain applications in future mobile Internet of Things systems, multiple access mobile edge computing appears to be an auspicious solution to solve the proof-of-work puzzles for mobile users. We first introduce a novel concept of edge computing for mobile blockchain. Then we introduce an economic approach for edge computing resource management. Moreover, a prototype of mobile edge computing enabled blockchain systems is presented with experimental results to justify the proposed concept.

Christian S. Perone

In this work, we propose a straightforward method to derive Elliptic Curve Digital Signature Algorithm (ECDSA) key pairs from embeddings created using Deep Learning and Metric Learning approaches. We also show that these keys allows the derivation of cryptocurrencies (such as Bitcoin) addresses that can be used to transfer and receive funds, allowing novel Blockchain-based applications that can be used to transfer funds or data directly to domains such as image, text, sound or any other domain where Deep Learning can extract high-quality embeddings; providing thus a novel integration between the properties of the Blockchain-based technologies such as trust minimization and decentralization together with the high-quality learned representations from Deep Learning techniques.

Shehar Bano, Alberto Sonnino, Mustafa Al-Bassam, Sarah Azouvi · 7 authors

The blockchain initially gained traction in 2008 as the technology underlying bitcoin, but now has been employed in a diverse range of applications and created a global market worth over $150B as of 2017. What distinguishes blockchains from traditional distributed databases is the ability to operate in a decentralized setting without relying on a trusted third party. As such their core technical component is consensus: how to reach agreement among a group of nodes. This has been extensively studied already in the distributed systems community for closed systems, but its application to open blockchains has revitalized the field and led to a plethora of new designs. The inherent complexity of consensus protocols and their rapid and dramatic evolution makes it hard to contextualize the design landscape. We address this challenge by conducting a systematic and comprehensive study of blockchain consensus protocols. After first discussing key themes in classical consensus protocols, we describe: first protocols based on proof-of-work (PoW), second proof-of-X (PoX) protocols that replace PoW with more energy-efficient alternatives, and third hybrid protocols that are compositions or variations of classical consensus protocols. We develop a framework to evaluate their performance, security and design properties, and use it to systematize key themes in the protocol categories described above. This evaluation leads us to identify research gaps and challenges for the community to consider in future research endeavours.

Nguyen Cong Luong, Zehui Xiong, Ping Wang, Dusit Niyato

Blockchain has recently been applied in many applications such as bitcoin, smart grid, and Internet of Things (IoT) as a public ledger of transactions. However, the use of blockchain in mobile environments is still limited because the mining process consumes too much computing and energy resources on mobile devices. Edge computing offered by the Edge Computing Service Provider can be adopted as a viable solution for offloading the mining tasks from the mobile devices, i.e., miners, in the mobile blockchain environment. However, a mechanism needs to be designed for edge resource allocation to maximize the revenue for the Edge Computing Service Provider and to ensure incentive compatibility and individual rationality is still open. In this paper, we develop an optimal auction based on deep learning for the edge resource allocation. Specifically, we construct a multi-layer neural network architecture based on an analytical solution of the optimal auction. The neural networks first perform monotone transformations of the miners' bids. Then, they calculate allocation and conditional payment rules for the miners. We use valuations of the miners as the data training to adjust parameters of the neural networks so as to optimize the loss function which is the expected, negated revenue of the Edge Computing Service Provider. We show the experimental results to confirm the benefits of using the deep learning for deriving the optimal auction for mobile blockchain with high revenue

Ahmed Elkahwagy

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Xueqin Liang, Zheng Yan

A number of information and resource sharing systems arise and become popular with the rapid development of communication technologies and mobile smart devices. The interactions between humans and machines are intense and their synergistic reactions have attracted special attention for the reason of forming so called Human–Machine Networks (HMN). HMNs refer to these networks where humans and machines work together to provide synergistic effects on their payoffs. Game theory, which can capture the interactions among players dexterously, has been widely used in solving various problems in HMN systems from the view of economics. In this paper, we extensively review the literature about game theoretical methods in HMNs, in particular focusing on its typical systems such as crowdsourcing, an elemental HMN and Internet of Things (IoT), a hybrid HMN, as well as Bitcoin. We propose a series of requirements to evaluate existing work. For reviewing and analyzing each system, we specify application purposes, players, strategies, game models and equilibria based on our proposed requirements. In the sequel, we identify a number of common and distinct open issues in HMNs and point out future research directions.

Cécile Pierrot, Benjamin Wesolowski

No abstract is available for this record.

Iris M. Barsan

Initial Coin Offerings (ICO) – a term intentionally mirroring Initial Public Offerings (IPO) – seem to be the new hype of the virtual currency community leading to an all-time high of the bitcoin of almost 5,000$ this year1. There is indeed a frenzy developing around ICOs reaching a record high of $1.7 billion in 20172 sparking an increasing interest from regulators on the American and Asian continents. Thus, ICOs have become a venture capital-raising tool for start-ups developing projects and applications on the blockchain and trying to escape the constraints of regulation. Regulation however seems to chatch up with ICOs. This paper analyzes ICOs from a legal perspective with a particular focus on European and French law.

Shuba Olena А., Honcharova Yuliia Yu., Bulygina Anastasia V.

The article is aimed at researching bitcoin, the digital currency. It has been found that Bitcoin is a cryptocurrency, that is, the virtual money, which has no material equivalent. The history of creation and development of cryptocurrency was reviewed. There is a reduction in volatility, which guarantees the security of currency, as well as the increase in currency volume and the inability to estimate the profitability of bitcoins. The dynamics of the value of digital currency in US dollars over recent years has been analyzed. Improvement of attitude of many countries to the considered cryptocurrency, in particular the USA, Germany, Spain, Canada, Australia, Israel and Scandinavian countries has been identified. The reasons of Ukraine’s interest in Bitcoin have been considered. Possibilities of creation of cryptocurrency on the territory of Ukraine have been analyzed, i.e. cost of electricity for mining, the legal status of mining firms, and the attitude of the National Bank of Ukraine to the digital currency. It has been concluded that the recognition of Bitcoin by the world countries in the future will allow it to be granted the status of world-wide currency.

Muhammad Reza Rizky Fauzi, Surya Michrandi Nasution, Marisa W. Paryasto

The present study discusses the workings of blockchain bitcoin in the transactions sector, on the development of today's emerging computers in the financial sector of blockchain bitcoin traction. In this case the author analyzes how the transaction is running, as well as how blockchain bitcoin is doing work in transactions on the system to make transactions. Transaction is a data structure that encodes the transfer of values between users with in a bitcoin system. Every transaction is a public entry in this bitcoin blockchain. And become a large transaction bookkeeping global.

Raja Sakti Arief Daulay, Surya Michrandi Nasution, Marisa W. Paryasto

The implementation research and analyze address blockchain on this bitcoin will have the results that refers to making address bitcoin a safe and boost security of address the bitcoin. The working mechanism of blockchain in making address bitcoin which is already in the blockchain system.

Volker Brühl

The phenomenon of virtual currencies has to be distinguished from the underlying distributed ledger technologies. Bitcoin and other cryptocurrencies need to be subject to strict financial regulation and supervision to ensure investor protection. At the same time, distributed ledger technologies will shape the future of the financial services in many respects. The disruptive potential is illustrated for selected financial products and processes.

M. Jancy Priya, Vanlin Sathya

A peer–to-peer allows online payments that sent directly from one party to another party without going through the financial institution. Digital signature is a part but the main benefit is lost, if a Trusted Third Party is still required to prevent digital signature. This digital signature uses peer–to-peer network. The network timestamps transaction by hashing them into an on-going chain of hash-based proof-of-work is done; it records that and cannot be changed without redoing the proof-of-work. The majority of CPU work is controlled by nodes. That are not cooperating to attack the network, they will generate the longest chain and outspace attackers.

Qing Zhou, Qingqing Zhang, Qi Zhang

In recent years, with the development of the Internet, network currency has gradually emerged. Bitcoin which is produced on the basis of complex algorithms has developed rapidly and attracted wide attention in academia. This paper explores the influence factors of bitcoin market transaction by analyzing the interaction between agents in bitcoin market transaction. Applying complex adaptive system modeling method based on multi-agent, this paper establishes an agent-based bitcoin market transaction model, and designs behavioral rules as well as transaction mechanism in detail for each agent in the process of market transaction. Then, we carry out a simulation on the Starlogo simulation platform and analyze the impact of the change in trader’s number on market transaction.

Russell O'Connor

Simplicity is a typed, combinator-based, functional language without loops and recursion, designed to be used for crypto-currencies and blockchain applications. It aims to improve upon existing crypto-currency languages, such as Bitcoin Script and Ethereum's EVM, while avoiding some of the problems they face. Simplicity comes with formal denotational semantics defined in Coq, a popular, general purpose software proof assistant. Simplicity also includes operational semantics that are defined with an abstract machine that we call the Bit Machine. The Bit Machine is used as a tool for measuring the computational space and time resources needed to evaluate Simplicity programs. Owing to its Turing incompleteness, Simplicity is amenable to static analysis that can be used to derive upper bounds on the computational resources needed, prior to execution. While Turing incomplete, Simplicity can express any finitary function, which we believe is enough to build useful ``smart contracts'' for blockchain applications.

Yutao Jiao, Ping Wang, Dusit Niyato, Zehui Xiong

Blockchain, an emerging decentralized security system, has been applied in many applications, such as bitcoin, smart grid, and Internet-of-Things. However, running the mining process may cost too much energy consumption and computing resource usage on handheld devices, which restricts the use of blockchain in mobile environments. In this paper, we consider deploying edge computing service to support the mobile blockchain. We propose an auction-based edge computing resource market of the edge computing service provider. Since there is competition among miners, the allocative externalities (positive and negative) are taken into account in the model. In our auction mechanism, we maximize the social welfare while guaranteeing the truthfulness, individual rationality and computational efficiency. Based on blockchain mining experiment results, we define a hash power function that characterizes the probability of successfully mining a block. Through extensive simulations, we evaluate the performance of our auction mechanism which shows that our edge computing resources market model can efficiently solve the social welfare maximization problem for the edge computing service provider.

Divesh Aggarwal, Gavin K. Brennen, Troy Lee, Miklós Sántha · 5 authors

The key cryptographic protocols used to secure the internet and financial transactions of today are all susceptible to attack by the development of a sufficiently large quantum computer. One particular area at risk is cryptocurrencies, a market currently worth over 100 billion USD. We investigate the risk posed to Bitcoin, and other cryptocurrencies, by attacks using quantum computers. We find that the proof-of-work used by Bitcoin is relatively resistant to substantial speedup by quantum computers in the next 10 years, mainly because specialized ASIC miners are extremely fast compared to the estimated clock speed of near-term quantum computers. On the other hand, the elliptic curve signature scheme used by Bitcoin is much more at risk, and could be completely broken by a quantum computer as early as 2027, by the most optimistic estimates. We analyze an alternative proof-of-work called Momentum, based on finding collisions in a hash function, that is even more resistant to speedup by a quantum computer. We also review the available post-quantum signature schemes to see which one would best meet the security and efficiency requirements of blockchain applications.

Giulio Malavolta, Pedro Moreno-Sánchez, Aniket Kate, Matteo Maffei · 5 authors

Permissionless blockchains protocols such as Bitcoin are inherently limited in transaction throughput and latency. Current efforts to address this key issue focus on off-chain payment channels that can be combined in a Payment-Channel Network (PCN) to enable an unlimited number of payments without requiring to access the blockchain other than to register the initial and final capacity of each channel. While this approach paves the way for low latency and high throughput of payments, its deployment in practice raises several privacy concerns as well as technical challenges related to the inherently concurrent nature of payments that have not been sufficiently studied so far. In this work, we lay the foundations for privacy and concurrency in PCNs, presenting a formal definition in the Universal Composability framework as well as practical and provably secure solutions. In particular, we present Fulgor and Rayo. Fulgor is the first payment protocol for PCNs that provides provable privacy guarantees for PCNs and is fully compatible with the Bitcoin scripting system. However, Fulgor is a blocking protocol and therefore prone to deadlocks of concurrent payments as in currently available PCNs. Instead, Rayo is the first protocol for PCNs that enforces non-blocking progress (i.e., at least one of the concurrent payments terminates). We show through a new impossibility result that non-blocking progress necessarily comes at the cost of weaker privacy. At the core of Fulgor and Rayo is Multi-Hop HTLC, a new smart contract, compatible with the Bitcoin scripting system, that provides conditional payments while reducing running time and communication overhead with respect to previous approaches. Our performance evaluation of Fulgor and Rayo shows that a payment with 10 intermediate users takes as few as 5 seconds, thereby demonstrating their feasibility to be deployed in practice.

Richard Adams, Beth Kewell, Glenn Parry

No abstract is available for this record.

Yan Chen

Over the past few years, Bitcoin has emerged as the first decentralized, global currency. The rise of Bitcoin has brought attention not only to digital currencies but also to the underlying technology empowering digital currencies: blockchain technology. A blockchain is a distributed ledger that records and secures transactions in a peer-to-peer network. Besides empowering digital currencies, blockchain technology has given innovators the capability of creating digital tokens to represent scarce assets, potentially reshaping the landscape of entrepreneurship and innovation. Blockchain tokens may democratize (1) entrepreneurship by giving entrepreneurs new ways to raise funds and engage stakeholders, and (2) innovation by giving innovators a new way to develop, deploy, and diffuse decentralized applications. Blockchain technology and tokens have sparked a new wave of innovation, which may start to revolutionize entrepreneurship and innovation.