Blockchain Papers

Min Cheol Chang, Yong Sauk Hau, Jae Chan Park, Jae Min Lee

Chang, Min Cheol MD; Hau, Yong Sauk PhD; Park, Jae Chan PhD; Lee, Jae Min MD Author Information

Lars Steinert, Christian Herff

Cryptocurrencies have recently received large media interest. Especially the great fluctuations in price have attracted such attention. Behavioral sciences and related scientific literature provide evidence that there is a close relationship between social media and price fluctuations of cryptocurrencies. This particularly applies to smaller currencies, which can be substantially influenced by references on Twitter. Although these so-called "altcoins" often have smaller trading volumes they sometimes attract large attention on social media. Here, we show that fluctuations in altcoins can be predicted from social media. In order to do this, we collected a dataset containing prices and the social media activity of 181 altcoins in the form of 426,520 tweets over a timeframe of 71 days. The containing public mood was then estimated using sentiment analysis. To predict altcoin returns, we carried out linear regression analyses based on 45 days of data. We showed that short-term returns can be predicted from activity and sentiments on Twitter.

Ho-Kyung Yang, Hyun-Jong Cha, You-Jin Song

With the recent increase in the number of IoT devices and the development of centralized management systems, risks in cyber space, including personal information phishing, malicious code infection, hacking, and DDos attack, are becoming major issues in the real world. The recently developed distributed data management technology, blockchain, provides reliability in transactions without the intervention of a third party. This new technology, blockchain, promotes integrity and reliability of transaction records by allowing for all network participants to jointly own and verify data, which was previously done by a central server. Due to distributed data management, the technology can reduce brokerage fees and construction costs, and guarantees high levels of integrity and security of data. This paper examines the effective identifier management using blockchain technology under the named data networking environment. The proposed system does not expose a specific user's identifier by creating a transaction using the content name of the identifier. The identifier can be safely stored and managed through such an identifier split management technique.

Erik P. M. Vermeulen, Mark Fenwick, Wulf A. Kaal

We live in a world that has historically been dominated by centralized, hierarchical organizations. Such organizations are characterized by (i) a centralized source of authority; (ii) a formal hierarchy with clearly defined “roles”; and, (iii) standardized operational systems and procedures dictated by that centralized authority/hierarchy. This type of organization has exerted an enormous influence on modern political, economic and social life, particularly in a business context. Regulatory models have been designed to support and sustain businesses organized in this way. Today, however, new digital technologies are disrupting this “old world” and introducing a shift in the practices and mindset of our society. New technologies are driving the emergence of “flatter”, more decentralized forms of organization. In this paper, we offer an analysis of how blockchain and related distributed ledger technologies are disrupting corporate organizations as an illustration of this broader “digital transformation.” The paper briefly introduces the digital transformation and main argument (Section 1); then considers how the digital transformation has led to the emergence of “platform” companies (Section 2). Since blockchain technology can be viewed as a next step in the “digital development” of a corporate organization, the paper then discusses the main features of blockchain technologies and smart contracts (Sections 3 & 4) and examines the often-made claim that these technologies are all just hype / a fad (Section 5). Section 6 explores why these technologies are so potentially disruptive in a business context and then introduces several examples of such blockchain-based business organizations, as well as possible future developments (Sections 7 and 8). Section 9 concludes.

Anik Islam, Md. Fazlul Kader, Soo Young Shin

Existing education systems are facing a threat of question paper leaking\n(QPL) in the exam which jeopardizes the quality of education. Therefore, it is\nhigh time to think about a more secure and flexible question sharing system\nwhich can prevent QPL issue in the future education system. Blockchain enables\na way of creating and storing transactions, contracts or anything that requires\nprotection against tampering, accessing etc. This paper presents a new scheme\nfor smart education, by utilizing the concept of blockchain, for question\nsharing. A two-phase encryption technique for encrypting question paper (QSP)\nis proposed. In the first phase, QSPs are encrypted using timestamp and in the\nsecond phase, previous encrypted QSPs are encrypted again using a timestamp,\nsalt hash and hashes from previous QSPs. These encrypted QSPs are stored in the\nblockchain along with a smart contract which helps the user to unlock the\nselected QSP. An algorithm is also proposed for selecting a QSP for the exam\nwhich picks a QSP randomly. Moreover, a timestamp based lock is imposed on the\nscheme so that no one can decrypt the QSP before the allowed time. Finally,\nsecurity is analyzed by proving different propositions and the superiority of\nthe proposed scheme over existing schemes is proven through a comparative study\nbased on the different features.\n

Byung-Wan Jo, Rana Muhammad Asad Khan, Yun‐Sung Lee

The Internet-of-things (IoT) and blockchain are growing realities of modern society, and both are rapidly transforming civilization, either separately or in combination. However, the leverage of both technologies for structural health monitoring (SHM) to enable transparent information sharing among involved parties and autonomous decision making has not yet been achieved. Therefore, this study combines IoT with blockchain-based smart contracts for SHM of underground structures to define a novel, efficient, scalable, and secure distributed network for enhancing operational safety. In this blockchain-IoT network, the characteristics of locally centralized and globally decentralized distribution have been activated by dividing them into core and edge networks. This division enhances the efficiency and scalability of the system. The proposed system was effective in simulation for autonomous monitoring and control of structures. After proper design, the decentralized blockchain networks may effectively be deployed for transparent and efficient information sharing, smart contracts-based autonomous decision making, and data security in SHM.

Damiano Di Francesco Maesa, Andrea Marino, Laura Ricci

No abstract is available for this record.

Sergi Delgado-Segura, Surya Bakshi, Cristina Pérez‐Solà, James Litton · 7 authors

Bitcoin relies on a peer-to-peer overlay network to broadcast transactions and blocks. From the viewpoint of network measurement, we would like to observe this topology so we can characterize its performance, fairness and robustness. However, this is difficult because Bitcoin is deliberately designed to hide its topology from onlookers. Knowledge of the topology is not in itself a vulnerability, although it could conceivably help an attacker performing targeted eclipse attacks or to deanonymize transaction senders. In this paper we present TxProbe, a novel technique for reconstructing the Bitcoin network topology. TxProbe makes use of peculiarities in how Bitcoin processes out of order, or "orphaned" transactions. We conducted experiments on Bitcoin testnet that suggest our technique reconstructs topology with precision and recall surpassing 90%. We also used TxProbe to take a snapshot of the Bitcoin testnet in just a few hours. TxProbe may be useful for future measurement campaigns of Bitcoin or other cryptocurrency networks.

Evgeniy Shishkin

Smart contracts are a special type of programs running inside a blockchain. Immutable and transparent, they provide means to implement fault-tolerant and censorship-resistant services. Unfortunately, its immutability causes a serious challenge of ensuring that a business logic and implementation is correct upfront, before publishing in a blockchain. Several big accidents have indeed shown that users of this technology need special tools to verify smart contract correctness. Existing automated checkers are able to detect only well known implementation bugs, leaving the question of business logic correctness far aside. In this work, we present a symbolic model-checking technique along with a formal specification method for a subset of Solidity programming language that is able to express both state properties and trace properties; the latter constitutes a weak analogy of temporal properties. We evaluate the proposed technique on the MiniDAO smart contract, a young brother of notorious TheDAO. Our Proof-of-Concept was able to detect a non-trivial error in the business logic of this smart contract in a few seconds.

Nikolaus Hautsch, Christoph Scheuch, Stefan Voigt

Abstract A blockchain replaces central counterparties with time-consuming consensus protocols to record the transfer of ownership. This settlement latency slows cross-exchange trading, exposing arbitrageurs to price risk. Off-chain settlement, instead, exposes arbitrageurs to costly default risk. We show with Bitcoin network and order book data that cross-exchange price differences coincide with periods of high settlement latency, asset flows chase arbitrage opportunities, and price differences across exchanges with low default risk are smaller. Blockchain-based trading thus faces a dilemma: Reliable consensus protocols require time-consuming settlement latency, leading to arbitrage limits. Circumventing such arbitrage costs is possible only by reinstalling trusted intermediation, which mitigates default risk.

Muoi Tran, Loi Luu, Min Suk Kang, Iddo Bentov · 5 authors

Bitcoin provides only pseudo-anonymous transactions, which can be exploited to link payers and payees -- defeating the goal of anonymous payments. To thwart such attacks, several Bitcoin mixers have been proposed, with the objective of providing unlinkability between payers and payees. However, existing Bitcoin mixers can be regarded as either insecure or inefficient.

André Greubel, Alexandra Dmitrienko, Samuel Kounev

In the Tor anonymity network, the distribution of topology information relies on the correct behavior of five out of the nine trusted directory authority servers. This centralization is concerning since a powerful adversary might compromise these servers and conceal information about honest nodes, leading to the full de-anonymization of all Tor users. Our work aims at distributing the work of these trusted authorities, such increasing resilience against attacks on core infrastructure components of the Tor network. In particular, we leverage several emerging technologies, such as blockchains, smart contracts, and trusted execution environments to design and prototype a system called SmarTor. This system replaces the directory authorities with a smart contract and a distributed network of untrusted entities responsible for bandwidth measurements. We prototyped SmarTor using Ethereum smart contracts and Intel SGX secure hardware. In our evaluation, we show that SmarTor produces significantly more reliable and precise measurements compared to the current measurement system. Overall, our solution improves the decentralization of the Tor network, reduces trust assumptions and increases resilience against powerful adversaries like law enforcement and intelligence services.

Rômulo Rhemo Palitot Braga, Arthur Augusto Barbosa Luna

This article analyzes some of the existing digital anonymity technologies, as well as their impact on the process and facilitation of the money laundering process. It presents the concept of superficial Internet and clarifies the difference between the Deep Web and the Dark Web, exposing how it works one of its most important operating structures, the TOR protocol. It also details the operation of BitCoin, one of the most important crypto-coins today, and draws a parallel on how these technologies can impact the practice of money laundering, as well as discusses the capacity of the mechanisms currently in place to curb and punish it. The anonymity guaranteed by the use of BitCoin is so much that in the first half of May 2017, hackers infected thousands of computers in dozens of countries, including Brazil, the United Kingdom, the United States, China, Russia, Spain and Italy, encrypting computer files and requiring redemption payment for the coded data.

Antônio Carlos Efing, Adrielly Pinho dos Santos

Smart contracts são criados por meio de códigos computacionais para execução automática de seus termos após a implementação da condição avençada pelas partes. Apresentam-se como fruto da Revolução Tecnológica, especialmente com o advento da internet e ganham relevância no mundo negocial após o surgimento da tecnologia blockchain, a qual permite o armazenamento dos códigos em cadeia de blocos, reduzindo os custos de execução contratual. Assim, os códigos que dão origem aos contratos inteligentes serão autoexecutáveis, autoaplicáveis e obrigatórios, e nada poderá interferir na produção dos efeitos jurídicos avençados pelas partes. São inúmeros desafios jurídicos impostos à realização dos smart contracts no Brasil, principalmente, porque inexistem leis específicas para tutela desta inovação contratual. A pesquisa buscou verificar a existência de obstáculos a execução destes contratos, à luz do princípio da função social dos contratos, por tratar-se norma principiológica cuja aplicação é indispensável a garantia do equilíbrio entre as partes durante todas as fases contratuais. Constatou-se, por meio do método dedutivo e procedimento monográfico, que as próprias características dos smart contracts executados em blockhain, obstam a efetividade das garantias inerentes ao princípio da função social, ante a irreversibilidade dos efeitos jurídicos produzidos, evidenciando, pois, a relevância do tema para a ciência jurídica.

Tsung-Ting Kuo, Rodney A. Gabriel, Lucila Ohno‐Machado

OBJECTIVE: Decentralized privacy-preserving predictive modeling enables multiple institutions to learn a more generalizable model on healthcare or genomic data by sharing the partially trained models instead of patient-level data, while avoiding risks such as single point of control. State-of-the-art blockchain-based methods remove the "server" role but can be less accurate than models that rely on a server. Therefore, we aim at developing a general model sharing framework to preserve predictive correctness, mitigate the risks of a centralized architecture, and compute the models in a fair way. MATERIALS AND METHODS: We propose a framework that includes both server and "client" roles to preserve correctness. We adopt a blockchain network to obtain the benefits of decentralization, by alternating the roles for each site to ensure computational fairness. Also, we developed GloreChain (Grid Binary LOgistic REgression on Permissioned BlockChain) as a concrete example, and compared it to a centralized algorithm on 3 healthcare or genomic datasets to evaluate predictive correctness, number of learning iterations and execution time. RESULTS: GloreChain performs exactly the same as the centralized method in terms of correctness and number of iterations. It inherits the advantages of blockchain, at the cost of increased time to reach a consensus model. DISCUSSION: Our framework is general or flexible and can also address intrinsic challenges of blockchain networks. Further investigations will focus on higher-dimensional datasets, additional use cases, privacy-preserving quality concerns, and ethical, legal, and social implications. CONCLUSIONS: Our framework provides a promising potential for institutions to learn a predictive model based on healthcare or genomic data in a privacy-preserving and decentralized way.

Azim Muhammad Fahmi, Noor Azah Samsudin, Aida Mustapha, Nazim Razali · 5 authors

In 2017, a significant number of individuals profited from the staggering growth of the price of Bitcoin from $800 USD in January to almost $20,000 USD in December. Because the cryptocurrency market being relatively new when compared to traditional markets such as stocks, foreign exchange, and gold, there is a significant lack of studies in regard to predicting its price behavior. This research is interested in evaluating a number of regression-based algorithms in predicting the price of the Bitcoin (BTC) against United States Dollar (USD). Among the algorithms that will be investigated include the Linear Regression (LR), Neural Network Regression (NNR), Bayesian Linear Regression (BLR), and Boosted Decision Tree Regression (BDTR). By applying such regression-based analysis algorithms, the findings f should further help document the behavior of such a brand new, challenging yet extremely lucrative market. Â

Christof Ferreira Torres, Julian Schütte, Radu State

The capability of executing so-called smart contracts in a decentralised manner is one of the compelling features of modern blockchains. Smart contracts are fully fledged programs which cannot be changed once deployed to the blockchain. They typically implement the business logic of distributed apps and carry billions of dollars worth of coins. In that respect, it is imperative that smart contracts are correct and have no vulnerabilities or bugs. However, research has identified different classes of vulnerabilities in smart contracts, some of which led to prominent multi-million dollar fraud cases. In this paper we focus on vulnerabilities related to integer bugs, a class of bugs that is particularly difficult to avoid due to some characteristics of the Ethereum Virtual Machine and the Solidity programming language.

Gabriel Axel Montes, Ben Goertzel

No abstract is available for this record.

Noe Elisa, Longzhi Yang, Fei Chao, Yi Cao

Abstract Electronic government (e-government) uses information and communication technologies to deliver public services to individuals and organisations effectively, efficiently and transparently. E-government is one of the most complex systems which needs to be distributed, secured and privacy-preserved, and the failure of these can be very costly both economically and socially. Most of the existing e-government systems such as websites and electronic identity management systems (eIDs) are centralized at duplicated servers and databases. A centralized management and validation system may suffer from a single point of failure and make the system a target to cyber attacks such as malware, denial of service attacks (DoS), and distributed denial of service attacks (DDoS). The blockchain technology enables the implementation of highly secure and privacy-preserving decentralized systems where transactions are not under the control of any third party organizations. Using the blockchain technology, exiting data and new data are stored in a sealed compartment of blocks (i.e., ledger) distributed across the network in a verifiable and immutable way. Information security and privacy are enhanced by the blockchain technology in which data are encrypted and distributed across the entire network. This paper proposes a framework of a decentralized e-government peer-to-peer (p2p) system using the blockchain technology, which can ensure both information security and privacy while simultaneously increasing the trust of the public sectors. In addition, a prototype of the proposed system is presented, with the support of a theoretical and qualitative analysis of the security and privacy implications of such system.

Pranay Gupta, T. Mandy Tham

No abstract is available for this record.

Mohammad Knio

This The virtual currency is a paramount in a strong economical situation of any country in the future, especially the countries that try to lead the world with its economy, this currency has been created to replace the traditional currency of the countries that can be issued by any central bank and put a value for it, but the virtual currency is a currency that no one can control and manipulate its value and no one can use it to control any country economical situation (c.f. Selgin, 1988).The virtual currency helps poor countries to develop its economy because it will have the same currency that any developed country has with the same value. But the virtual currency will face a lot of problems before entering to market(Gandal, N., &Halaburda, H. (2014) and will face a lot of barriers that will stop the development of the state economy, some of those problems are: the culture of the country and the government laws and policies, plus there is an important problem that it will face and it represent by the economic agreements and the Unified Banks Network (e.g. Jerin, 2014).To solve those problems the research will use the qualitative method with an interpretive research philosophy, that helps the research to use specific case study that have similar situation to collect the second data and use the interview to collect the primary data.The interview that is made with experts will show some solution that answer the research question and it can be applied and the step to apply it to receive to needed solution to let the virtual currency be accepted in the market (Gandal, N., &Halaburda, H. (2014). Therefore, the government started to encourage the citizen and the companies to use this new currency, and they created an environment that helps those users to trust and accept it.This currency will face a lot of obstacles and problems at the beginning, the government will try to put plans and long term strategies to solve these problems before they occur, starting from creating and issuing new laws and policies arriving to create a large and strong educational advertising to let the citizen know this new currency and its benefits.Also, the private sectorsare responsible too, especially the bank sectors because they have the principle relation with this field and they have to motivate their customers to use it (Gans, J., &Halaburda, 2013).From this research, we will try to find some solutions that the concerned sector need to apply to let the virtual currency enter the market and let the citizen trust it and start trading with it (Gandal, N., &Halaburda, H. (2014).

Wai Wai Wong, Chin Lay Gan

In this era of increasing cyber dependency in business dealings there is huge potential in the adoption of Distributed Ledger Technologies (DLT) particularly in the context of smart contract in the commercial world. The phenomenon of smart contract operates independently without the cumbersome need to engage any intermediary and is capable of executing specific task.(Thake, 2018) People relates it more to a piece of code (known as a software agent) that is designed to execute certain tasks if pre-defined conditions are met. Such tasks are often embedded within, and performed on a distributed ledger.”(Stark, 2016) However, if one accepts the contention that smart contract is not merely as a set of computer code but a smart legal contract which contains obligations and legal terms that are enforceable, hence, in programming or writing smart contract, one must ensure that the software developers who design smart contract take note of the legal rules and principles behind the specific type of contract in question. It has been argued that there is too much dependency on the programming aspect in the creation of smart contracts by programmers and computer scientists. (Khalil et al., 2017)

Antônio Pereira dos Santos, Zenon Chaczko

Blockchain has been evolving and gaining new heights over the years. The shift in the perspective is allowing new user cases beyond the cryptocurrency space. Cryptocurrencies are digital assets supported by the complexities of cryptography, game theory and peer-to-peer networks. Blockchain became a popular platform for decentralized applications, as well as a valuable tool for start-ups seeking fundraising. The aim of this research paper is to review and assess the status quo for each branch of use cases, and then analyze the enabling and inhibiting factors influencing the adoption of blockchain. These findings permit a broader comprehension over the concepts backing blockchain. It will help new users to establish strategies, develop solutions and encourage the employment of blockchain technology.

D. P. Zegzhda, D. A. Moskvin, A. V. Myasnikov

Abstract The article studies the architectures of the modern systems of decentralized data storage and processing, applicability of the blockchain technology in these systems, existing security threats in comparison with the decentralized systems, and methods of security assurance allowing avoidance of these threats.