The most fundamental purpose of blockchain technology is to enable\npersistent, consistent, distributed storage of information. Increasingly common\nare authentication systems that leverage this property to allow users to carry\ntheir personal data on a device while a hash of this data is signed by a\ntrusted authority and then put on a blockchain to be compared against. For\ninstance, in 2015, MIT introduced a schema for the publication of their\nacademic certificates based on this principle. In this work, we propose a way\nfor users to obtain assured identities based on face-to-face proofing that can\nthen be validated against a record on a blockchain. Moreover, in order to\nprovide anonymity, instead of storing a hash, we make use of a scheme of Brands\nto store a commitment against which one can perform zero-knowledge proofs of\nidentity. We also enforce the confidentiality of the underlying data by letting\nusers control a secret of their own. We show how our schema can be implemented\non Bitcoin's blockchain and how to save bandwidth by grouping commitments using\nMerkle trees to minimize the number of Bitcoin transactions that need to be\nsent. Finally, we describe a system in which users can gain access to services\nthanks to the identity records of our proposal.\n
We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized cloud storage, has privacy by design, is open source, is more secure, is scalable, is more sustainable, has community ownership, is inexpensive, and is potentially faster, more efficient, and more reliable. We propose that a RAIN-style architecture could form the backbone of the Internet of Things that likely will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration.
Bitcoinsâ technology brings a new level of innovation to business and communication across the world. However, the advantages of a virtual currency payment system face the threat from criminal activities occurring over a pseudonymous network where there is virtually no current regulation to cover illegal transactions. The current situation in Georgia is as follows: the second Bitcoinâs processing datacenter has opened in Georgia. While the virtual money is new even in developed countries, more unusual it is for Georgia, where local economists are more skeptical toward cryptocurrency. Therefore, they believe that electronic money is not controlled by any central bank that gives a lot of opportunities for illegal transactions. According to the Georgian experts, bitcoin is a very risky currency that can be used for money laundering, as it is completely uncontrolled. However, the Georgian central bank system claims that bitcoins are not dangerous, and the lack of awareness gives rise to talk about money laundering. The biggest challenge seems to be regulation of Bitcoin without hindering the potential for growth. While there is usually certainly a chance that Bitcoin could fail or be pushed out of existence by a more innovative technology, policymakers must be careful not to hinder a technology that could change the way global economy functions.
The mining process in blockchain requires solving a proof-of-work puzzle, which is resource expensive to implement in mobile devices due to the high computing power and energy needed. In this paper, we, for the first time, consider edge computing as an enabler for mobile blockchain. In particular, we study edge computing resource management and pricing to support mobile blockchain applications in which the mining process of miners can be offloaded to an edge computing service provider. We formulate a two-stage Stackelberg game to jointly maximize the profit of the edge computing service provider and the individual utilities of the miners. In the first stage, the service provider sets the price of edge computing nodes. In the second stage, the miners decide on the service demand to purchase based on the observed prices. We apply the backward induction to analyze the sub-game perfect equilibrium in each stage for both uniform and discriminatory pricing schemes. For the uniform pricing where the same price is applied to all miners, the existence and uniqueness of Stackelberg equilibrium are validated by identifying the best response strategies of the miners. For the discriminatory pricing where the different prices are applied to different miners, the Stackelberg equilibrium is proved to exist and be unique by capitalizing on the Variational Inequality theory. Further, the real experimental results are employed to justify our proposed model.
Public blockchain networks using proof of work (PoW)-based consensus protocols are considered as a promising platform for decentralized resource management with financial incentive mechanisms. In order to maintain a secured, universal state of the blockchain, PoW-based consensus protocols financially incentivize the nodes in the network to compete for the privilege of block generation through cryptographic puzzle solving. For rational consensus nodes, i.e., miners with limited local computational resources, offloading the computation load for PoW to the cloud/fog providers (CFPs) becomes a viable option. In this paper, we study the interaction between the CFPs and the miners in a PoW-based blockchain network using a game theoretic approach. In particular, we propose a lightweight infrastructure of the PoW-based blockchains, where the computation-intensive part of the consensus process is offloaded to the cloud/fog. We formulate the computation resource management in the blockchain consensus process as a two-stage Stackelberg game, where the profit of the CFP and the utilities of the individual miners are jointly optimized. In the first stage of the game, the CFP sets the price of offered computing resource. In the second stage, the miners decide on the amount of service to purchase accordingly. We apply backward induction to analyze the subgame perfect equilibria in each stage for both uniform and discriminatory pricing schemes. For uniform pricing where the same price applies to all miners, the uniqueness of the Stackelberg equilibrium is validated by identifying the best response strategies of the miners. For discriminatory pricing where the different prices are applied, the uniqueness of the Stackelberg equilibrium is proved by capitalizing on the variational inequality theory. Further, the real experimental results are employed to justify our proposed model.
In 2008, following the outbreak of the global financial crisis, a new trading system emerged that was made possible by cryptographically-produced currencies. Among them, the most popular digital cryp-tocurrency is undoubtedly the Bitcoin. This alternative way of trading quickly captured the interest of both businesses and consumers. Combined with a general lack of confidence towards financial institu-tions, central governments, and the effect of capital controls imposed across several countries, Bitcoins begun being used extensively for funds transfer across borders and general payments. How-ever, it is unclear whether the use of Bitcoins is extensive enough so as to lead to complete or partial disintermediation of monetary transactions, and whether users understand how the technology works and what are the inherit risks of this alternative payment mechanism. This paper addresses these ques-tions through a survey-based study, conducted within the Greek context, where capital controls are still active and awareness regarding cryptocurrencies seems to be on the rise. Our findings show that despite that end-users of Bitcoin are somewhat concerned with regards to security issues, they are nevertheless interested in its use for identifying new business opportunities and bypassing residency-based measures, such as capital controls.
Bitcoin is a decentralized digital currency, which works peer-to-peer without a centralized repository, and is accepted as a form of payment all around the world. The âpublic ledgerâ, which registers transactions, is known as the block chain. A conventional ledger records bills and notes which are used by an organization, but in the case of Bitcoin these are simply data âentriesâ in the Blockchain sequence. Business Intelligence (BI), according to Investpedia, refers to the procedural and technical infrastructure that collect, store and analyses the data produced by a field of activities or by an individual company. BI is meant to take in all the data being generated by a business and present easy to digest performance measures and trends that will inform management decisions. The paper shows the BI steps and procedures that will help a Bitcoin user, owner or broker make the best decision possible in order to maximize their profits and financial security.
Halal supply chains are vulnerable due to their credence quality attributes, importance of maintaining halal integrity throughout the supply chain, need to avoid doubt, lack of control of food norms, and sensitivity of the Muslim consumer towards halal. These vulnerabilities make halal supply chains complex to design, manage, and optimise. Transparency of halal supply chains is needed in order to ensure trust and authenticity of a halal brand. The principle of a shared database that is safe, open and verifiable without a central operator is an attractive proposition to embed trust and authenticity for halal food, cosmetics, home care, and pharmaceuticals.
Abstract This paper argues that many soâcalled digital technologies can be construed as notational technologies, explored through the example of Monegraph, an art and digital asset management platform built on top of the blockchain system originally developed for the cryptocurrency bitcoin. As the paper characterizes it, a notational technology is the performance of syntactic notation within a field of reference, a technologized version of what Nelson Goodman called a ânotational system.â Notational technologies produce abstracted entities through positive and reliable, or constitutive, tests of socially acceptable meaning. Accordingly, this account deviates from typical narratives of blockchains (usually characterized as Turing or state machines), instead demonstrating that blockchain technologies are effective at managing digital assets because they produce abstracted identities through the performance of notation. Since notational technologies rely on configurations of socially acceptable meaning, this paper also provides a philosophical account of how blockchain technologies are socially embedded.
Open access
Blockchain Technology Applications and Security
Neuroethics, Human Enhancement, Biomedical Innovations
Abstract A blockchain can be considered a technological phenomenon that is made up of different interconnected and autonomous systems. Such systems are referred to here as cyberâphysical systems: complex interconnections of cyber and physical components. When cyberâphysical systems are interconnected, a new whole consisting of a system of systems is created by the autonomous systems and their intercommunication and interaction. In a blockchain, individual systems can independently make decisions on joint information transactions. The decisionâmaking procedures needed for this are executed based on faultâtolerant communication and voting and consensus procedures, while the results of these decisionâmaking procedures are stored in distributed ledgers. Due to the intercommunication, interaction, and independent decision making by autonomous systems, the new whole of a blockchain is a complex entity. Complexity science rather than the usual reductionist scientific approach can help us better understand the behaviour of the new and continuously developing whole of a blockchain as a technological phenomenon.
Cryptocurrency and blockchain technologies are recently gaining wide adoption since the introduction of Bitcoin, being distributed, authority-free, and secure. Proof of Work (PoW) is at the heart of blockchain's security, asset generation, and maintenance. Although simple and secure, a hash-based PoW like Bitcoin's puzzle is often referred to as âuselessâ, and the used intensive computations are considered âwasteâ of energy. A myriad of Proof of âsomethingâ alternatives have been proposed to mitigate energy consumption; however, they either introduced new security threats and limitations, or the âworkâ remained far from being really âusefulâ. In this work, we introduce Proof of eXercise (PoX): a sustainable alternative to PoW where an eXercise is a real world matrix-based scientific computation problem. We provide a novel study of the properties of Bitcoin's PoW, the challenges of a more ârationalâ solution as PoX, and we suggest a comprehensive approach for PoX.
Petra Isenberg, Christoph Kinkeldey, JeanâDaniel Fekete
We contribute a visual exploration system for analyzing the behavior of individual entities exchanging Bitcoins. Bitcoin is a cryptocurrency, popular for allowing pseudonymous financial transactions. The Bitcoin blockchain is the public ledger of the Bitcoin system holding data on millions of individual transactions between pseudonymous addresses. These addresses belong to individual entities such as people, services, or enterprises. Understanding how the Bitcoin system is used, however, is difficult because it is unclear which addresses belong to the same entities. Our tool addresses this
problem by clustering addresses and displaying transaction detail for individual entities
Abstract This paper argues that the practical implementation of blockchain technology can be considered an institution of property similar to legal institutions. Invoking Penner's theory of property and Hegel's system of property rights, and using the example of bitcoin, it is possible to demonstrate that blockchain effectively implements all necessary and sufficient criteria for property without reliance on legal means. Blockchains eliminate the need for a thirdâparty authority to enforce exclusion rights, and provide a system of universal access to knowledge and discoverability about the property rights of all participants and how the system functions. The implications of these findings are that traditional property relations in society could be replaced by or supplemented with blockchain models, and implemented in new domains.
Mehrdad Salimitari, Mainak Chatterjee, Murat YĂŒksel, Eduardo L. Pasiliao
It is predicted that cryptocurrencies will play an important role in the global economy. Therefore, it is prudent for us to understand the importance and monetary value of such cryptocurrencies, and strategize our investments accordingly. One of the ways to obtain cryptocurrency is via mining. As solo mining is not possible because of the computational requirements, pool mining has gained popularity. In this paper, we focus on Bitcoin and its pools. With more than 20 pools in the network of Bitcoin and other cryptocurrencies, it becomes challenging for a new miner to decide the pool he must join such that the profit is maximized. We use prospect theory to predict the profit that a specific miner, given his hash rate power and electricity costs, is expected to make from each pool. A utility value is calculated for each pool based on its recent performance, hash rate power, total number of the pool members, reward distribution policy of the pool, electricity fee in the new miner's region, pool fee, and the current Bitcoin value. Then, based on these parameters during a certain time duration, the most profitable pool is found for that miner. We show how the utility values from a pool varies with electricity fee and dollar equivalent of a Bitcoin. To find the accuracy of our predictions, we mine Bitcoin by joining 5 different pools- AntPool, F2Pool, BTC.com, Slushl'ool, and BatPool. Using an Antminer 55 for each pool, we mine Bitcoin for 40 consecutive days. Results reveal that our prospect theoretic predictions are consistent with what we actually mine; however predictions using expected utility theory are not as close.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Blockchain is an emergent technology concept that enables the decentralized and immutable storage of verified data. Over the last few years, it has increasingly attracted the attention of different industries. Especially in Fintech, Blockchain is hyped as the silver bullet that might overthrow todayâs payment handling. Slowly, the logistics and supply chain management community realizes how profoundly Blockchain could affect their industry. To shed light on this emerging field, we conducted an online survey and asked logistics professionals for their opinion on use case exemplars, barriers, facilitators, and the general prospects of Blockchain in logistics and supply chain management. We found most of our participants are fairly positive about this new technology and the benefits it offers. However, factors like the hierarchical level, Blockchain experiences, and the industry sector have a significant impact on the participantsâ evaluation. We reason that the benefits over existing IT solutions must be carved out more carefully and use cases must be further explored to get a rather conservative industry, like logistics, more excited about Blockchain.
A BlockChain is an open record of all digital money exchanges that have ever been executed. It is constantly growing as âcompletedâ blocks are added to it with a new set of recordings. The blocks are added to the blockchain in a linear, chronological order. Each PC associated with the Bitcoin systematize a customer that plays out the task of approving and handing-off exchanges gets a duplicate of the blockchain, which gets downloaded naturally after joining the Bitcoin arrange. The blockchain has finish data about the addresses and their adjusts ideal from the beginning piece to the most as of late finished square. Transactions between individuals have always been a part and parcel of human society for the division of labour made people interdependent. The medium of transaction has also been evolving along with the evolution of society and human consciousness from barter system to commodity money to fiat currency and now to digital currency or cryptocurrency. But as the evolution is a form of error correction, the problem of double spending in digital currency was solved by a distributed ledger system called BlockChain. Since 2008 onwards the blockchain technology has been separated from Bitcoins to be injected to many other problems related especially to banking transactions. Blockchain innovation empowers the production of decentralized monetary forms, savvy contracts and clever resources that can be controlled over the Internet.
The recent growth of financial technology ventures involves several types of financial players, including stock exchanges. Many of them are exploring blockchain applications to their multiple business lines, focusing in particular on post trading activities. Potential benefits include the reduction in counterparty risk and post trading costs as well as the increase of liquidity and transparency. At current stage exchanges are mainly exploring the technology looking for proofs of concept, with the exception of some more advanced projects like at Nasdaq and ASX. The mass adoption will require longer efforts and is expected to come in a decade, at least. Fintech developments are receiving strong attention also by regulators and international organizations, given the potential of distributed ledger technology for both competition enhancement and cyber risk reduction. A coordination between market players and regulators is essential to guarantee the effective implementation of new technologies, as their benefits can be delivered only in presence of a common framework and a proper management of risks.
Research background: The year 2016 ended the period of the migration from national payment services to the SEPA instruments. At the same time, however, it has become apparent that some problems remained unresolved. Overcoming them requires finding suitable technological solutions. The potential of the distributed ledger technology (DLT) is currently being explored by the financial sector and its implementation may affect the SEPA schemes in a variety of dimensions. Purpose of the article: The aim of the article was to determine the potential impact that the DLT transfer to the banking sector may have on the functioning of the SEPA in the future. The paper presents SEPA?s assumptions and the current status of the project as well as the DTL?s concept. It describes the technology transfer implications for the banking industry and compares the SEPA schemes currently operating with those based on the DLT. It also indicates the opportunities and threats that are the consequence of the new technology implementation and examines their significance for the SEPA. Methods: In the article, a qualitative analysis is supplemented with a quantitative one. Elements of descriptive statistics have been used to characterize the functioning of the main pillars of the SEPA schemes. The final conclusions are based on the comparative analysis of the SEPA schemes and developed DLT applications. Findings & value added: The existing problems might be solved by supplementing the SEPA payment schemes currently operating with the applications based on the DLT. The systems that will be subsequently developed will provide the required real-time processing and a global reach. They will also extend the functionalities of the SEPA schemes with the ability to transfer other currencies. The implementation of this technology will result not only in new financial products but, first of all, in creating new business models. Consequently, we may expect a modification of the currently operating SEPA schemes, based on their supplementation rather than total replacement in a short time frame.
Numerous studies ranging from concept papers and reviews were conducted on the matter of blockchain and digital currencies. However, those two areas are not well researched due to its being a new area of research. Furthermore, the research on blockchain applications in the Islamic financial system precisely the potential of digital currency in providing a better alternative to current fiat money system which will be the scope of this article. The aim of revolves around exploring the potential and capability of introducing a digital currency that fulfills the Islamic law (Shariâah) functions of money and provides a more stable currency than fiat money. The method used for analyzing this object includes a library research on related topics that helps understanding the functions of money and digital currencies and study of several cases that can assist in fulfilling the objectives of this paper in introducing an Islamic digital currency through detailed research of Islamic theory of money and civilization as well as the developments of blockchain, our findings point towards the ability of introducing a Shariâah-compliant digital currency if all the issues on validity are addressed and resolved. However, the area of digital currencies and blockchain requires further research from a Shariâah perspective to facilitate a better understanding on the topic.
Pradip Kumar Sharma, MuâYen Chen, Jong Hyuk Park
The recent expansion of the Internet of Things (IoT) and the consequent explosion in the volume of data produced by smart devices have led to the outsourcing of data to designated data centers. However, to manage these huge data stores, centralized data centers, such as cloud storage cannot afford auspicious way. There are many challenges that must be addressed in the traditional network architecture due to the rapid growth in the diversity and number of devices connected to the internet, which is not designed to provide high availability, real-time data delivery, scalability, security, resilience, and low latency. To address these issues, this paper proposes a novel blockchain-based distributed cloud architecture with a software defined networking (SDN) enable controller fog nodes at the edge of the network to meet the required design principles. The proposed model is a distributed cloud architecture based on blockchain technology, which provides low-cost, secure, and on-demand access to the most competitive computing infrastructures in an IoT network. By creating a distributed cloud infrastructure, the proposed model enables cost-effective high-performance computing. Furthermore, to bring computing resources to the edge of the IoT network and allow low latency access to large amounts of data in a secure manner, we provide a secure distributed fog node architecture that uses SDN and blockchain techniques. Fog nodes are distributed fog computing entities that allow the deployment of fog services, and are formed by multiple computing resources at the edge of the IoT network. We evaluated the performance of our proposed architecture and compared it with the existing models using various performance measures. The results of our evaluation show that performance is improved by reducing the induced delay, reducing the response time, increasing throughput, and the ability to detect real-time attacks in the IoT network with low performance overheads.
Blockchain technology has evolved from being an immutable ledger of\ntransactions for cryptocurrencies to a programmable interactive the environment\nfor building distributed reliable applications. Although, blockchain technology\nhas been used to address various challenges, to our knowledge none of the\nprevious work focused on using blockchain to develop a secure and immutable\nscientific data provenance management framework that automatically verifies the\nprovenance records. In this work, we leverage blockchain as a platform to\nfacilitate trustworthy data provenance collection, verification, and\nmanagement. The developed system utilizes smart contracts and open provenance\nmodel (OPM) to record immutable data trails. We show that our proposed\nframework can efficiently and securely capture and validate provenance data,\nand prevent any malicious modification to the captured data as long as the\nmajority of the participants are honest.\n