Blockchain Papers

Andreas Auinger, René Riedl

In this paper, we discuss a fundamental question: What is the nature of trust in the blockchain context? Thereby, we critically examine widely-held assumptions on blockchain and trust. In particular, we examine the assumption that the blockchain is trust-

Putra Astomo, Farhanuddin Farhanuddin

Artikel ini ingin menjawab permasalahan utama terkait pajak di daerah. Dengan menggunakan pendekatan normatif, dapat digambarkan bahwa era otonomi daerah, dikaitkan dengan pajak daerah melalui asas desentralisasi, pemerintah daerah diberikan kewenangan untuk memungut pajak daerah. Pajak tersebut dalam rangka meningkatkan pendapatan asli daerah dan menyelenggarakan serta membiayai pembangunan di daerah. Dasar hukum bagi pemerintah daerah untuk memungut pajak adalah Undang-Undang Pajak Daerah dan Retribusi Daerah. Selain itu, Pemerintah Daerah juga membentuk peraturan di daerah sebagai peraturan teknis dibidang pajak daerah dan retribusi daerah. Peraturan yang dibentuk di daerah disebut politik hukum, yang merupakan kebijakan hukum negara untuk mencapai tujuan nasionalnya dengan membentuk hukum untuk mengatur sesuatu hal yang berkaitan langsung dengan kepentingan nasional. Political Law of Regional Tax in Polewali Mandar District West Sulawesi This article aims to answer the main problems related to taxes in the region. This is a normative research, aiming to describe the regional autonomy era to be associated with regional taxes through decentralization principle, local governments are given the authority to collect regional taxes. The tax is used to increase local revenue and organize the finance development in the region. The legal basis for local governments to collect taxes is the Regional Tax Law and Regional Retribution. In addition, the Regional Government also established regulations in the region as technical regulations of regional taxes and regional retribution. Regulations established in the region are called legal politics, which are the state legal policies to achieve national goals by establishing laws to regulate issues related to national interests.

Rafał Skowroński

No abstract is available for this record.

Pietro Ferraro, Christopher King, Robert Shorten

Directed Acylic Graphs (DAGs) are emerging as an attractive alternative to traditional blockchain architectures for distributed ledger technology (DLT). In particular DAG ledgers with stochastic attachment mechanisms potentially offer many advantages over blockchain, including scalability and faster transaction speeds. However, the random nature of the attachment mechanism coupled with the requirement of protection against double-spend transactions leaves open the possibility that not all transactions will be eventually validated. Such transactions are said to be orphaned, and will never be validated. Our principal contribution is to propose a simple modification to the attachment mechanism for the Tangle (the IOTA DAG architecture). This modification ensures that all transactions are validated in finite time, and preserves essential features of the popular Monte-Carlo selection algorithm. In order to demonstrate these results we derive a fluid approximation for the Tangle (in the limit of infinite arrival rate) and prove that this fluid model exhibits the desired behavior. We also present simulations which validate the results for finite arrival rates.

Jens Mattke, Christian Maier, Lea Müller, Tim Weitzel

Bitcoin could revolutionize the system of payments, yet most individuals do not use Bitcoin as a means of payment. As the success of Bitcoin as a means of payment depends upon a high number of individuals using Bitcoin, this study examines why individuals

Israa Alqassem, Iyad Rahwan, Davor Svetinović

Bitcoin is a cryptocurrency and a decentralized semi-anonymous peer-to-peer payment system in which the transactions are verified by network nodes and recorded in a public massively replicated ledger called the blockchain. Bitcoin is currently considered as one of the most disruptive technologies. Bitcoin represents a paradox of opposing forces. On one hand, it is fundamentally social, allowing people to transact in a peer-to-peer manner to create and exchange value. On the other hand, Bitcoin's core design philosophy and user base contain strong anti-social elements and constraints, emphasizing anonymity, privacy, and subversion of traditional centralized financial systems. We believe that the success of Bitcoin, and the financial ecosystem built around it, will likely rely on achieving an optimal balance between these social and anti-social forces. To elucidate the role of these forces, we analyze the evolution of the entire Bitcoin transaction graph from its inception, and quantify the evolution of its key structural properties. We observe that despite its different nature, the Bitcoin transaction graph exhibits many universal dynamics typical of social networks. However, we also find that Bitcoin deviates in important ways due to anonymity-seeking behavioral patterns of its users. As a result, the network exhibits a two-orders-of-magnitude larger diameter, sparse treelike communities, and an overwhelming majority of transitional or intermediate accounts with incoming and outgoing edges but zero cumulative balances. These results illuminate the evolutionary dynamics of the most popular cryptocurrency, and provide us with initial understanding of social networks rooted in and driven by anti-social constraints.

Ke Liang

We present Fission, a new permissionless blockchain that achieves scalability in both terms of system throughput and transaction confirmation time, while at the same time, retaining blockchain's core values of equality and decentralization. Fission overcomes the system throughput bottleneck by employing a novel Eager-Lazy pipeling model that achieves very high system throughputs via block pipelining, an adaptive partitioning mechanism that auto-scales to transaction volumes, and a provably secure energy-efficient consensus protocol to ensure security and robustness. Fission applies a hybrid network which consists of a relay network, and a peer-to-peer network. The goal of the relay network is to minimize the transaction confirmation time by minimizing the information propagation latency. To optimize the performance on the relay network in the presence of churn, dynamic network topologies, and network heterogeneity, we propose an ultra-fast game-theoretic relay selection algorithm that achieves near-optimal performance in a fully distributed manner. Fission's peer-to-peer network complements the relay network and provides a very high data availability via enabling users to contribute their storage and bandwidth for information dissemination (with incentive). We propose a distributed online data retrieval strategy that optimally offloads the relay network without degrading the system performance. By re-innovating all the core elements of the blockchain technology - computation, networking, and storage - in a holistic manner, Fission aims to achieve the best balance among scalability, security and decentralization.

Hira Salah ud din Khan, Zhiqiang Ma, Mohammed Abubakari Sadick, Abdul‐Aziz Ibn Musah

This study aims to investigate how a Psychological contract breach can mediate the relationship between perceptions of organizational politics and job attitudes and how political skill and work ethic can influence the negative association between perceptions of organizational politics and job attitudes. A systematic sampling method was used with a sampling size of 310 faculty members of public sector universities of Pakistan. Data were analyzed by using partial least squares structural equations modeling PLS-SEM to test the hypotheses by Smart PLS software. The findings revealed that the perception of politics is significantly and negatively related to job attitudes and indirectly through psychological contract breach. Moreover, the results indicated a significant moderating effect of work ethic on the relationship between the perception of politics and job attitudes. However, political skill did not moderate the relationship between perceptions of organizational politics and job attitudes. Moreover, research implications and limitations are elucidated.

Michèle Finck

No abstract is available for this record.

Neha Parashar, Farida Rasiwala

No abstract is available for this record.

Mariya Benji, M. Sindhu

No abstract is available for this record.

Remo Pfister, Keerthikan Thurairatnam

Introduction: 
\nThe study work focuses on designing a smart contract language (named "Lazo") for the Bazo blockchain. The Bazo blockchain is a research blockchain to test different mechanisms and algorithms. In the current version, a Proof of Stake consensus algorithm and a virtual machine to execute Bazo intermediate language(opcodes) are integrated. However, writing smart contracts in Bazo opcodes is time
\nconsuming and error-prone. The goal of this study work is to design a high-level language which is easier to read and write smart contracts.
\n
\nProcedure / Result: 
\nBefore designing Lazo, 24 existing smart contract languages are collected and roughly analyzed to identify the key characteristics of a language for the blockchain. Thereafter, three popular and well elaborated languages, namely Solidity, Vyper and Scilla, were analyzed in great detail. Their supported features, syntax and contract examples were also documented. With the acquired knowledge about smart contracts, Lazo language was designed in an agile manner.
\n
\nResult: 
\nAs a result, Lazo is designed to be a statically typed, imperative and non-turing complete programming language. All language features are documented with illustrative code snippets. The Lazo grammar is also written in ANTLR and
\nverified with Java. Furthermore, contract examples from Solidity are translated to Lazo in order to prove that the real-world use cases can be programmed with Lazo
\nas well.
\n
\nIn a follow-up thesis, a compiler could be developed to compile Lazo programs into Bazo virtual machine instructions.

Mengting Liu, F. Richard Yu, Yinglei Teng, Victor C. M. Leung · 5 authors

Blockchain-based video streaming systems aim to build decentralized peer-to-peer networks with flexible monetization mechanisms for video streaming services. On these blockchain-based platforms, video transcoding, which is computationally intensive and time-consuming, is still a major challenge. Meanwhile, the block size of the underlying blockchain has significant impacts on the system performance. Therefore, this paper proposes a novel blockchain-based framework with an adaptive block size for video streaming with mobile edge computing (MEC). First, we design an incentive mechanism to facilitate collaboration among content creators, video transcoders, and consumers. In addition, we present a block size adaptation scheme for blockchain-based video streaming. Moreover, we consider two offloading modes, i.e., offloading to the nearby MEC nodes or a group of device-to-device (D2D) users, to avoid the overload of MEC nodes. Then, we formulate the issues of resource allocation, scheduling of offloading, and adaptive block size as an optimization problem. We employ a low-complexity alternating direction method of the multipliers-based algorithm to solve the problem in a distributed fashion. Simulation results are presented to show the effectiveness of the proposed scheme.

Asheer Jaywant Ram

Purpose Bitcoin is the best-known cryptocurrency which currently holds the largest market capitalisation and is regarded as a standard example of a cryptocurrency. There is, however, no consensus as to the nature of the Bitcoin. The purpose of this paper is to determine whether Bitcoin represents a new asset class by building on prior research. Design/methodology/approach The prior literature on asset classes is explored in detail and then applied to the Bitcoin. Four key criteria of asset classes are discussed, namely, investability, politico-economic profile, correlation of returns and risk-reward profile. Statistical techniques are used to inform the conclusions for the third and fourth criteria. Findings This research finds that the Bitcoin represents a distinct alternative investment and asset class. There are significant opportunities for investment. The politico-economic profile of the decentralised and consensus-based Bitcoin is dissimilar to other asset classes. The Bitcoin shares little or no correlation with other asset classes. Using Sharpe Ratios, it is shown that the Bitcoin provides risk-adjusted returns over and above most asset classes. Research limitations/implications The aim of this research is to present a normative exploration into the asset class nature of the Bitcoin and, as a result, the aim is not to create positivist generalisable conclusions. This paper does not address cryptocurrencies, other than Bitcoin and does not constitute a detailed manual on modern portfolio theory. Originality/value This research adds to finance paradigm research on the Bitcoin by including a developing country perspective on Bitcoin as an asset class as prior studies have concentrated on developed country settings. Further, this research introduces recent economic data (2014 to 2017) in the form of daily observations to enhance prior understanding. It is important to understand if the Bitcoin represents an alternative investment and new asset class as this may affect investment decisions.

Panagiota-Gerogia Saranti, Dimitra Chondrogianni, Stylianos Karatzas

No abstract is available for this record.

Dara, Jabbar Sabil, Syarifuddin Usman

Historically, the means of payment has evolved from time to time. The current phenomenon is Bitcoin, claimed by its users as a means of future payments, that have been the major attention of many people, from people in business to students. The research question in this study was how the existence of Bitcoin as a medium of exchange is, and how its existence as a medium of exchange is viewed based on the maqāṣid al-syar 'īyah. This used the literature research method and the maqāṣidī approach by applying the tarjih maslahat method. The existence of Bitcoin as a medium of exchange is considered valid because of the 'urf recognition. However, it requires a legal status from the government because it is related to al-maslahat al-mmāmmah, the mafsadat (damage) value of Bitcoin is higher than its maslahat (benefit) value. Hence, it is concluded that Bitcoin is valid as a medium of exchange. Still, its use must be limited due to the mafsadat (harm) probability that is more dominant at the ḍarūriyyāt (primary needs) level, following the principle of "rejecting the harm is prioritized than realizing the benefit."
 Abstrak: Berdasarkan sejarah, alat pembayaran dari masa ke masa telah mengalami evolusi, pada saat ini terdapat sebuah fenomena yaitu fenomena Bitcoin yang diklaim oleh para penggunanya sebagai alat pembayaran masa depan yang telah banyak menyita perhatian orang mulai dari kalangan pengusaha hingga mahasiswa. Bitcoin memiliki beberapa kelebihan jika dibandingkan dengan alat pembayaran yang biasa digunakan, di antaranya yaitu sifatnya yang desentralisasi sehingga tidak ada pengendali pusat yang akan ikut campur di dalamnya. Sedangkan pada kebiasaannya, alat pembayaran di suatu wilayah berada di bawah pengawasan pemerintah karena alat pembayaran tergolong kepada kebutuhan primer yang menyangkut kesejahteraan umum. Pertanyaan penelitian dalam skripsi ini adalah bagaimana eksistensi Bitcoin sebagai alat tukar dan bagaimana keberadaan Bitcoin sebagai alat tukar berdasarkan maqāṣid al-syar‘īyah. Dalam penelitian ini penulis menggunakan metode penelitian kepustakaan dan pendekatan maqāṣidī dengan menerapkan metode tarjih maslahat. Keberadaan Bitoin sebagai alat tukar dianggap sah karena terdapat pengakuan secara ‘urf. Akan tetapi status sah tersebut perlu mendapatkan pengesahan pemerintah karena terkait dengan al- maslahat al-‘āmmah, nilai mafsadat pada Bitcoin lebih dominan jika dibandingkan dengan nilai maslahatnya. Dari paparan di atas disimpulkan bahwa keberadaan Bitcoin sah sebagai alat tukar, namun penggunaannya merupakan sesuatu yang harus dibatasi karena probabilitas mafsadatnya lebih dominan yang berada pada tingkat ḍarūriyyāt.. Hal ini sesuai dengan kaidah “menolak mafsadat di dahulukan dari pada mewujudkan maslahat.”
 Keyword: Eksistensi, Bitcoin, Maqāṣid al-Syar‘īyah.

U. M. Ramya, PALUKURI SINDHUJA, RA Atsaya, B. Bavya Dharani · 5 authors

No abstract is available for this record.

Stefan SFITCHI

This paper intends to review the need of cryptocurrency on the European and International market. Why cryptocurrency is bad and good at the same time for the international financial market is one of the main issues of this paper. Where are Bitcoin, Ethereum, Ripple, Bitcoin Cash, Litecoin going to and why cryptocurrencies are necessary on today’s market. Although there is no sure thing on crypto, on the long term, the market keeps going up and there is much interest in this direction.

AmirAli Nazari, Reza Keypour

No abstract is available for this record.

Luis Alberto Cruz Salazar, Óscar Amaury Rojas Alvarado, Édgar Chacón

No abstract is available for this record.

Efpraxia D. Zamani, Ying He, Matthew Phillips

The adoption of blockchain technology is taking place at a fast pace. Security features inherent in blockchain make it resistant to attack, but they do not make it immune, and blockchain security risks do exists. This paper details the associated risks and concerns of the blockchain. We explore relevant standards and regulations related to blockchain and survey and analyze 38 blockchain incidents to determine the root cause to provide a view of the most frequent vulnerabilities exploited. The paper reviews six of these 38 incidents in greater detail. The selection is made by choosing incidents with the most frequent root cause. In the review of the incidents, the paper details what happened and why and aims to address what could have been done to mitigate the attack. The paper concludes with a recommendation on a framework to reduce cyber security risks when using blockchain technologies.

Dimaz Ankaa Wijaya, Fengkie Junis, Dony Ariadi Suwarsono

Blockchain technology has enjoyed a massive adoption in cryptocurrencies such as Bitcoin. Following the success, many people have started to explore the possibility of implementing blockchain technology in different fields. We propose smart stamp duty, a system which can revolutionize the way stamp duty is managed and paid. The smart stamp duty offers significant improvements on the convenience when paying stamp duty. At the same time, the blockchain technology also provides the auditability of the transaction data. Smart stamp duty enables the expansion of the existing electronic stamp duty application to retail level as well as allows the taxpayers to pay the stamp duty of their electronic documents. Our proposed system also enables the taxpayers to print their electronic documents without losing the paid electronic-based stamps.

Rong Wang, Wei‐Tek Tsai, Juan He, Can Liu · 6 authors

In recent years, artificial intelligence (AI) has played an increasingly important role in the medical field. AI based on big data analysis and deep learning algorithms has become the core driving force for the future development of the medical industry, but the biggest obstacle to its development is incompleteness and inaccuracy of medical data. The main reason is that medical big data is difficult to achieve sharing. This paper studies and analyzes the problems of medical big data sharing, proposes a medical data sharing platform based on permissioned blockchains (BCs), which uses dual-BCs architecture (Account BC and transaction BC), Concurrent Byzantine Fault Tolerance (CBFT) consensus mechanism, encryption technology and smart contract technology. Account BC (ABC) is used to store user data hash after encryption and transaction BC (TBC) is used to process computing tasks. The use of encryption technology ensures that users have full autonomy in their own medical data. Smart contract technology is used to enable users to set up different access permissions of medical data. A TBC can be used by multiple ABCs and TBC does not save users' medical data, but only obtains users' medical data from ABCs when needs computation. When the computing task is completed, the TBC deletes all users' medical data and packages the operation record to save into ABCs, thereby it realizes data sharing while protecting users' privacy. In addition, this paper compares the functions with other medical data systems, analyzes and compares their advantages and disadvantages. Finally, the conclusions and future works of the medical data sharing platform based on BC technology are prospected.

Matija Kontak

Ovaj rad razmatra pametne ugovore i nov način financiranja utemeljen na njima − inicijalnu ponudu kriptovaluta (ICO). Riječ je o novim načinima sklapanja i praćenja izvršenja ugovora koji su dobili na značaju pojavom blockchain tehnologije. U radu se razmatraju značajke pametnih ugovora iz pravne perspektive. Uzimaju se u obzir moguća rješenja pitanja prisilnosti izvršenja pametnih ugovora, promatra mogućnost primjene pametnih ugovora, iznose se uočeni nedostatci; praktični i pravni problemi. Posebno se ističe problem interpretacije normi u vezi s pametnim ugovorima uspoređujući ih s EDI-jem (electronic data interchange). Predstavlja se pravna regulacija koja je značajna za ugovore, s posebnim osvrtom na tzv. Howey test kao i djelovanje tržišnih regulatora i zakonodavaca u ovom području, promatra se fenomen inicijalne ponude kriptovaluta (ICO) u kontekstu pravne regulacije. Prikazuje se kako djeluje tipičan ICO te što u pravnom smislu dobiju ulagači u ICO. Postoje brojni slučajevi prijevare ulagača vezanih uz ICO pa se razmatra reakcija nadležnih tijela. Prikazuje se evolucija ICO-a koji vremenom sve više nastoje legalizirati svoj status unutar postojećeg pravnog okvira. Iznosi se primjer Malte, prve zemlje koja je kodificirala ovo područje. Prikazuje se novonastala pravna industrija specijalizirana za ICO. Primijećeno je da fenomeni kriptovaluta, pametnih ugovora i ICO-a izazivaju zabrinutost vlasti i u pogledu terorizma, pranja novca i utaje poreza, zbog čega se može očekivati daljnja aktivnost zakonodavaca. Na kraju, ističe se moguća zaštita investitora od prijevare u vidu pravnog okvira zaštite potrošača u EU te primjer kriptovalute iz Hrvatske koja prikazuje prilike i opasnosti koje ove pojave donose.