Blockchain Papers

Ahmet Şensoy

No abstract is available for this record.

Aleksandar Đorđević, Miloš Todorović

The connection between financial innovation and information technology industry has provided and kept the crypto currencies for some ten years on the market, a kind of offset of monetary evolution after the introduction of virtual, electronic and digital money. Although their essence is still wrapped up under the veil of secrets, the facts show that the value of Bitcoin as the first crypto currency has a rising trend, and that an increasing number of firms and individuals are deciding to use it. This will result in the emergence of over 1000 new crypto currencies. This paper explains the emergence and functioning of the Bitcoin, its characteristics and functions, the benefits and risks that it carries, as well as possible scenarios of further development of the international monetary system with crypto currencies.

Aaron Wright, Primavera De Filippi

Since Bitcoin appeared in 2009, the digital currency has been hailed as an Internet marvel and decried as the preferred transaction vehicle for all manner of criminals. It has left nearly everyone without a computer science degree confused: Just how do you “mine” money from ones and zeros?\nThe answer lies in a technology called blockchain, which can be used for much more than Bitcoin. A general-purpose tool for creating secure, decentralized, peer-to-peer applications, blockchain technology has been compared to the Internet itself in both form and impact. Some have said this tool may change society as we know it. Blockchains are being used to create autonomous computer programs known as “smart contracts,” to expedite payments, to create financial instruments, to organize the exchange of data and information, and to facilitate interactions between humans and machines. The technology could affect governance itself, by supporting new organizational structures that promote more democratic and participatory decision making.\nPrimavera De Filippi and Aaron Wright acknowledge this potential and urge the law to catch up. That is because disintermediation—a blockchain’s greatest asset—subverts critical regulation. By cutting out middlemen, such as large online operators and multinational corporations, blockchains run the risk of undermining the capacity of governmental authorities to supervise activities in banking, commerce, law, and other vital areas. De Filippi and Wright welcome the new possibilities inherent in blockchains. But as Blockchain and the Law makes clear, the technology cannot be harnessed productively without new rules and new approaches to legal thinking.

Bailu Fu, Zhan Shu, Xiaogang Liu

Motivated by the recent blockchain technology originally built for bitcoin transactions, various industries are exploring the opportunities to redefine their existing operational systems. In this study, an innovative environmentally sustainable solution is proposed for the fashion apparel manufacturing industry (FAMI), which is energized by blockchain. Incorporating the Emission Trading Scheme (ETS), and a novel “emission link” system, the proposed framework exposes carbon emission to the public and establishes a feature to reduce the emissions for all key steps of clothing making. Fully compatible with Industry 4.0, blockchain provides decentralization, transparency, automation, and immutability characteristics to the proposed framework. Specifically, the blockchain supported ETS framework, the carbon emissions of clothing manufacturing life cycle, and the emission link powered procedures are introduced in detail. A case study is provided to demonstrate the carbon emission evaluation procedure. Finally, a multi-criteria evaluation is performed to demonstrate the benefits and drawbacks of the proposed system.

Marco Alberto Javarone, Craig Wright

Bitcoins and Blockchain technologies are attracting the attention of different scientific communities. In addition, their widespread industrial applications and the continuous introduction of cryptocurrencies are also stimulating the attention of the public opinion. The underlying structure of these technologies constitutes one of their core concepts. In particular, they are based on peer-to-peer networks. Accordingly, all nodes lie at the same level, so that there is no place for privileged actors as, for instance, banking institutions in classical financial networks. In this work, we perform a preliminary investigation on two kinds of network, i.e. the Bitcoin network and the Bitcoin Cash network. Notably, we analyze their global structure and we try to evaluate if they are provided with a small-world behavior. Results suggest that the principle known as 'fittest-gets-richer', combined with a continuous increasing of connections, might constitute the mechanism leading these networks to reach their current structure. Moreover, further observations open the way to new investigations into this direction.

Marco Alberto Javarone, Craig Wright

Bitcoins and Blockchain technologies are attracting the attention of different scientific communities. In addition, their widespread industrial applications and the continuous introduction of cryptocurrencies are also stimulating the attention of the public opinion. The underlying structure of these technologies constitutes one of their core concepts. In particular, they are based on peer-to-peer networks. Accordingly, all nodes lie at the same level, so that there is no place for privileged actors as, for instance, banking institutions in classical financial networks. In this work, we perform a preliminary investigation on two kinds of network, i.e. the Bitcoin network and the Bitcoin Cash network. Notably, we analyze their global structure and we try to evaluate if they are provided with a small-world behavior. Results suggest that the principle known as 'fittest-gets-richer', combined with a continuous increasing of connections, might constitute the mechanism leading these networks to reach their current structure. Moreover, further observations open the way to new investigations into this direction.

Mauro Conti, Ankit Gangwal, Sushmita Ruj

Bitcoin cryptocurrency system enables users to transact securely and pseudo-anonymously by using an arbitrary number of aliases (Bitcoin addresses). Cybercriminals exploit these characteristics to commit immutable and presumably untraceable monetary fraud, especially via ransomware; a type of malware that encrypts files of the infected system and demands ransom for decryption. In this paper, we present our comprehensive study on all recent ransomware and report the economic impact of such ransomware from the Bitcoin payment perspective. We also present a lightweight framework to identify, collect, and analyze Bitcoin addresses managed by the same user or group of users (cybercriminals, in this case), which includes a novel approach for classifying a payment as ransom. To verify the correctness of our framework, we compared our findings on CryptoLocker ransomware with the results presented in the literature. Our results align with the results found in the previous works except for the final valuation in USD. The reason for this discrepancy is that we used the average Bitcoin price on the day of each ransom payment whereas the authors of the previous studies used the Bitcoin price on the day of their evaluation. Furthermore, for each investigated ransomware, we provide a holistic view of its genesis, development, the process of infection and execution, and characteristic of ransom demands. Finally, we also release our dataset that contains a detailed transaction history of all the Bitcoin addresses we identified for each ransomware.

Meisser, Luzius, Gabriela Hauser-Spühler

Bitcoin und die zugrunde liegende Technologie der Blockchain sind längst keine Randphänomene mehr. Zwar ist Bitcoin in vielerlei Hinsicht neuartig. Das steht aber einer Einordnung als «Geld im weiteren Sinn» bzw. als «Kryptowährung» nicht im Weg. Bitcoin ient zurzeit primär als Spekulationsobjekt, aber auch zur Wertaufbewahrung und als Zahlungsmittel. Während das Bitcoin-System nur die Übertragung von Bitcoins erlaubt, ist die Blockchain von Ethereum, der zweitgrössten Kryptowährung, frei programmierbar and erlaubt die Emission beliebiger «Tokens». Diese können Währungen, Anleihen, Aktien oder beliebige andere Vermögenswerte mit oder ohne vom Emittenten garantierten Wert darstellen. Kryptowährungen haben das Potenzial, einen Digitalisierungsschub im Finanzbereich auszulösen. Um dieses Potenzial zu realisieren, bedarf es aber noch der Klärung verschiedener Rechtsfragen und der Beseitigung rechtlicher Hürden.

Jiao Jiao, Shuanglong Kan, Shang‐Wei Lin, David Sanán · 6 authors

Bitcoin has attracted everyone's attention and interest recently. Ethereum (ETH), a second generation cryptocurrency, extends Bitcoin's design by offering a Turing-complete programming language called Solidity to develop smart contracts. Smart contracts allow creditable execution of contracts on EVM (Ethereum Virtual Machine) without third parties. Developing correct smart contracts is challenging due to its decentralized computation nature. Buggy smart contracts may lead to huge financial loss. Furthermore, smart contracts are very hard, if not impossible, to patch once they are deployed. Thus, there is a recent surge of interest on analyzing/verifying smart contracts. While existing work focuses on EVM opcode, we argue that it is equally important to understand and define the semantics of Solidity since programmers program and reason about smart contracts at the level of source code. In this work, we develop the structural operational semantics for Solidity, which allows us to identify multiple design issues which underlines many problematic smart contracts. Furthermore, our semantics is executable in the K framework, which allows us to verify/falsify contracts automatically.

Ruchi Mittal, M. P. S. Bhatia

In the modern era, researchers are predicting prices of various kinds of cryptocurrency to understand their trend in the sector of finance. In this paper, we focus on price prediction of cryptocurrencies based on a period, i.e., for the year 2013 to 2018. From our research, we have identified the highest prices for bitcoin for historical dates and trained Long Short-Term Memory Networks to learn and predict the highest rate for a future period. Thus, trend analysis of cryptocurrency prices has been done, and neural networks have been leveraged to determine from time series data and predict future values.

Andrew Sward, Ivy Vecna, Forrest Stonedahl

This paper provides the first comprehensive survey of methods for inserting arbitrary data into Bitcoin’s blockchain. Historical methods of data insertion are described, along with lesser-known techniques that are optimized for efficiency. Insertion methods are compared on the basis of efficiency, cost, convenience of data reconstruction, permanence, and potentially negative impact on the Bitcoin ecosystem.

Andreas Freund, Danielle Stanko

Starting with BitTorrent and then Bitcoin, decentralized technologies have been on the rise over the last 15+ years, gaining significant momentum in the last 2+ years with the advent of platform ecosystems such as the Blockchain platform Ethereum. New projects have evolved from decentralized games to marketplaces to open funding models to decentralized autonomous organizations. The hype around cryptocurrency and the valuation of innovative projects drove the market cap of cryptocurrencies to over a trillion dollars at one point in 2017. These high valued technologies are now enabling something new: globally scaled, decentralized business models. Despite their valuation and the hype, these new business ecosystems are frail. This is not only because the underlying technology is rapidly evolving, but also because competitive markets see a profit opportunity in exponential cryptocurrency returns. This extracts value from these ecosystems, which could lead to their collapse, if unchecked. In this paper, we explore novel ways for decentralized economies to protect themselves from, and coexist with competitive markets at a global scale utilizing decentralized technologies such as Blockchain.

Rishabh Bhatia, Saaransh Gupta, Sanchit Sharma

No abstract is available for this record.

منير ماهر أحمد, أحمد سفيان عبد الله, عبد الله بن شريف

No abstract is available for this record.

E. Pohl, César Najera Reyes

Resumen: El dinero debe ser una de las creaciones humanas más exitosas en términos de extensión y masividad. Sus formas, sin embargo, son múltiples. Por ejemplo, hoy presenciamos un boom de criptomonedas que amenaza con dejar obsoleto al dinero físico. Pero, tal como agudamente muestra este texto, sin importar cuan digital sea una criptomoneda, su creación sí tiene efectos físicos a gran escala, especialmente en términos de consumo energético y huella de carbono.

Σωτήριος Σταμπέρνας, Sotirios Stampernas

Η τεχνολογία κατανεμημένου καθολικού είναι μια βάση δεδομένων όσον αφορά τις συναλλαγές που, αντί να αποθηκεύεται σε μια κεντρική τοποθεσία, κατανέμεται σε ένα δίκτυο πολλών υπολογιστών. Συνήθως, όλα τα μέλη του δικτύου μπορούν να διαβάζουν τις πληροφορίες και, ανάλογα με τις άδειες που τους έχουν δοθεί, να προσθέτουν στοιχεία. Ο γνωστότερος τύπος τεχνολογίας κατανεμημένου καθολικού είναι η αλυσίδα συστοιχιών (blockchain). Όπου οι συναλλαγές ομαδοποιούνται σχηματίζοντας συστοιχίες (blocks) οι οποίες συνδέονται μεταξύ τους με χρονολογική σειρά δημιουργώντας μια αλυσίδα (chain). Αυτή είναι και η τεχνολογία πίσω από τα κρυπτονομίσματα τα που ξεκίνησαν με την έλευση του Bitcoin. Η πρόσφατη επικέντρωση στην τεχνολογία της αλυσίδας συστοιχιών προήλθε από την εμπορική επιτυχία του Bitcoin και της προσοχής που έτυχε από τους ερευνητές και τις επιχειρήσεις. Σε αυτή την διπλωματική εργασία ασχολούμαστε με την τρέχουσα κατάσταση της αλυσίδας συστοιχιών και επιπλέον με μια εφαρμογή πέραν των κρυπτονομισμάτων, που ονομάζεται έξυπνο συμβόλαιο. Επιπλέον, συγκρίνουμε πέντε πλατφόρμες αλυσίδας συστοιχιών που μπορούν να υποστηρίξουν έξυπνα συμβόλαια επικεντρώνοντας την ανάλυση σε μια γενική περιγραφή τους, στις κύριες τεχνολογικές ιδιότητές τους και στα χρηματοοικονομικά τους στοιχεία. Επιπρόσθετα, θα παρουσιάσουμε μια ανάλυση κόστους-οφέλους και μια αξιολόγηση ασφάλειας των έξυπνων συμβολαίων σημειώνοντας τα σχετικά θέματα παρέχοντας ένα σύνολο πιθανών λύσεων. Τέλος, θα δείξουμε μια πρακτική εφαρμογή και τη διαδικασία και την ευελιξία της διαδικασίας δημιουργίας ενός έξυπνου συμβολαίου σε ένα περιβάλλον με το διαδίκτυο των πραγμάτων (Internet of Things).

Abdullah Al-Shehabi

Bitcoin, the world’s most valued cryptocurrency, uses a network of computers across the globe to create an immutable transaction record on a public ledger known as the blockchain. The blockchain consists of a series of timestamped blocks, where each block contains a series of transactions selected for inclusion in the block, generally based on how high of a fee the transaction allocates to the party responsible for confirming the transaction. Estimating an appropriate fee for Bitcoin transactions is a challenge for many transacting parties using Bitcoin as a digital currency. This work aims to help Bitcoin users save funds in their transaction fees when building multisig transactions by providing fee estimates that referenced the current state of the unconfirmed transaction pool using the perceptron machine learning classification algorithm. 4

Muhammad Mansab Uzair, Emadul Karim, Shair Sultan, Syed Sheeraz Ahmed

The block chain technology has been in the topic of much discussion due to its successful application in the crypto currency known as “Bitcoin" which has investment experts, economists, billion dollar financial institutes, big banks as well as governments taking sides on whether it should be legitimized and used as a currency or make it illegal to be used as a means of exchange. However, experts from different field like supply chain management and even from the medical field are more interested in how the block chain technology’s decentralized record keeping and numerous other benefits can be of use to them in their fields of work. This study concentrates on the block chain being used for real estate record keeping, since most geography’s have different procedures for record keeping, this study focuses on Defence Housing Authority in Karachi to check what the impact of applying the block chain technology to this area in Karachi would have on investors, real estate agents, residents and the government.

Cansu Şarkaya İçellioğlu, Merve Büşra Engin Öztürk

Güvenlik açısından kriptoloji (şifreleme) bilimini kullanan, dijital ve sanal bir para birimi anlamına gelen kriptopara, son yıllarda en çok tartışılan ekonomik kavramlardan biri olmuştur. Kriptopara, herhangi bir döviz kuruna ya değerli bir madene bağlı olmamakla birlikte, herhangi bir yasal otorite tarafından da kontrol edilememektedir. En başarılı kriptopara olarak değerlendirilen Bitcoin, ilk çıktığı yıldan bu yana çok yüksek bir oranda değerlenmesinden ötürü cazip bir yatırım aracı olarak görülmekte, ancak taşıdığı belirsizlik ve risklerden ötürü çeşitli endişeleri de beraberinde getirmektedir. Bu çalışmada Bitcoin’in özellikleri ve işleyişi ele alınarak, Bitcoin ile seçili döviz kurları arasındaki ilişki araştırılmaktadır. Araştırmada birim kök testleri uygulanmış, seriler arasındaki uzun dönemli ilişki Engel-Granger Eşbütünleşme testi ve Johansen Testi ile ve kısa dönemli ilişki Granger nedensellik testi ile sınanmıştır. Çalışmanın sonucunda Bitcoin ile Dolar, Euro, Sterlin, Yen ve Yuan arasında uzun ve kısa dönemli bir ilişkinin varlığına rastlanamamıştır.

Muhammad Saad, Aziz Mohaisen

In 2017, the Blockchain-based crypto currency market witnessed enormous growth. Bitcoin, the leading crypto currency, reached all-time highs many times over the year leading to speculations to explain the trend in its growth. In this paper, we study Bitcoin and explore features in its network that explain its price hikes. We gather data and analyze user and network activity that highly impact Bitcoin price. We monitor the change in the activities over time and relate them to economic theories. We identify key network features that determine the demand and supply dynamics of a crypto currency. Finally, we use machine learning methods to construct models that predict Bitcoin price. Our regression model predicts Bitcoin price with 99.4% accuracy and 0.0113 root mean squared error (RMSE).

Fabian Ritz, Alf Zugenmaier

Many of today's crypto currencies use blockchains as decentralized ledgers and secure them with proof of work. In case of a fork of the chain, Bitcoin's rule for achieving consensus is selecting the longest chain and discarding the other chain as stale. It has been demonstrated that this consensus rule has a weakness against selfish mining in which the selfish miner exploits the variance in block generation by partially withholding blocks. In Ethereum, however, under certain conditions stale blocks don't have to be discarded but can be referenced from the main chain as uncle blocks yielding a partial reward. This concept limits the impact of network delays on the expected revenue for miners. But the concept also reduces the risk for a selfish miner to gain no rewards from withholding a freshly minted block. This paper uses a Monte Carlo simulation to quantify the effect of uncle blocks both to the profitability of selfish mining and the blockchain's security in Ethereum (ETH). A brief outlook about a recent Ethereum Classic (ETC) improvement proposal that weighs uncle blocks during the selection of the main chain will be given.

Sumitra Samal

Bit coin is a type of crypto currency and worldwide payment system. It allows system to work without a central bank or single administrator and the first decentralized digital currency. Bit coin was invented by an unknown person or group of people under the name Satoshi Nakamoto. The network is peer-to-peer and transactions between the users are direct which are verified by network nodes through the use of cryptography and recorded in a public distributed ledger which is replicated, shared and synchronized digital data called a block chain. Block chain is used as the core technology for the transaction of bit currency, as block chain uses the concept of public and private key. People might think that the lack of control could mean chaos, but this is not true at all because the technology (block chain) behind bit coin is one of the most accurate and secured ever created.

Viktor Diordiiev

Introduction. Blockchain technology is becoming one of the main drivers of innovation in the global economy. Its adoption will have a huge impact on how businesses and governments operate and on the way people organize their everyday lives. Financial services industry is the one experiencing the biggest impact of the blockchain disruption so far, while financial institutions are among the first adopters of the technology. At the same time, being a relatively traditional industry, shipping has not yet seen many use cases with blockchain, but the technology is able to change this industry dramatically. Aim and tasks. As the industries of finance and shipping have huge potential in the blockchain space and often interact, determining how the blockchain technology adoption can influence the industries of finance and shipping in the future was the main purpose of this article. Research results. To fulfill this purpose, it was important to describe the origins of the blockchain technology, its main characteristics, functioning principles and consensus algorithms. Supported by the recent hype, cryptocurrencies are the biggest use case for blockchain so far, therefore, the article analyzes the largest of them, including Bitcoin, Ethereum and some others, as well as the cryptocurrency market as a whole. The level of worldwide adoption of blockchain and the overall market size are defined further in the article. Various applications in finance are also mentioned, paying particular attention to the insurance industry. Based on this information, the key areas in which blockchain can disrupt finance and insurance are identified. As the number of blockchain companies increases rapidly, the two main fundraising channels for such companies, venture capital and initial coin offering, are analyzed and compared. The ways in which blockchain may impact the shipping services industry are identified further. Conclusion. Afterwards, the article describes a number of blockchain consortia formed by public institutions and private entities to research and test possible applications of the technology across various industries and countries. While the potential of blockchain is still largely undiscovered, all the gathered information and performed research help to make a conclusion that the blockchain technology will have a big impact on many different industries, including financial and shipping services. The coming years will definitely see an exponentially growing interest in blockchain in academic and business fields, as the technology becomes more and more mainstream.

Davide Frey, Marc X. Makkes, Pierre-Louis Roman, François Taı̈ani · 5 authors

Blockchains have a storage scalability issue. Their size is not bounded and they grow indefinitely as time passes. As of August 2017, the Bitcoin blockchain is about 120 GiB big while it was only 75 GiB in August 2016. To benefit from Bitcoin full security model, a bootstrapping node has to download and verify the entirety of the 120 GiB. This poses a challenge for low-resource devices such as smartphones. Thankfully, an alternative exists for such devices which consists of downloading and verifying just the header of each block. This partial block verification enables devices to reduce their bandwidth requirements from 120 GiB to 35 MiB. However, this drastic decrease comes with a safety cost implied by a partial block verification. In this work, we enable low-resource devices to fully verify subchains of blocks without having to pay the onerous price of a full chain download and verification; a few additional MiB of bandwidth suffice. To do so, we propose the design of diet nodes that can securely query full nodes for shards of the UTXO set, which is needed to perform full block verification and can otherwise only be built by sequentially parsing the chain.