Abstract This paper delves into the question: How does an entrepreneur commercialising an open source technology (an “open entrepreneur”) respond when an underlying infrastructure that is maintained by a distributed and heterogeneous community become stigmatised, particularly when the source of the stigma is unclear? Research has found that, when faced with stigma, the most effective and robust strategy for established nondigital firms is to try to and create a distance from it. Open entrepreneurs with different ideologies would likely benefit from similar actions; however, the interdependencies created when they rely upon a digital infrastructure may make this strategy impossible. Given the tensions between ideological heterogeneity and a shared infrastructure, how—and why—do open entrepreneurs respond to stigma? This paper extends existing literature on stigma by developing a model of ideologically mediated responses to stigma by open entrepreneurs through an inductive study based upon interviews, archival, and forum data. We further contribute to extant literature on open entrepreneurship by proposing a model of ideologically mediated responses to stigma, which is grounded in group identity theory. We also build on digital infrastructure literature by proposing the concept of digital infrastructure anchoring . Lastly, we show how ideological heterogeneity leads to business model heterogeneity among open entrepreneurs and discuss the practical implications of this research.
AbedAlqader Swedan, Ahmad N. Khuffash, Othman Othman, Ahmed Awad
As technology evolves, more and more devices are connected to the Internet. The popularity and increasing significance of cryptocurriences are drawing attention, and crybercriminals are trying to utilize the resources and steal the processing power of these devices. It is highly likely that there are billions of devices that are maliciously mining cryptocurrency for the benefit of a cybercriminal without noticing the damage they may be causing. This paper is proposed because there is a huge need to professionally defend and protect against the misuse of assets in order to avoid losses, both financially and operationally, and how it is possible to mitigate with this rising trend.
The Enterprise Ethereum Client Specification by the Enterprise Ethereum Alliance defines the requirements which Ethereum Clients offering private smart contract capabilities should comply with. This specification though ground breaking, misses some important blockchain requirements and does not fully consider the requirements of Ethereum Clients offering Private Sidechain capabilities. This paper presents the case for Private Sidechains and defines requirements to be complied with to deliver this technology. The capabilities of three blockchain clients have been analysed based on the requirements: Quorum, Parity, and Hyperledger Fabric. Quorum and Hyperledger Fabric operate as private consortium blockchains where as Parity delivers private transaction capabilities on top of Ethereum MainNet. These differing approaches has led to different strengths and weaknesses which has resulted in each client not complying with one or more key requirement. In particular, none of the reviewed blockchain clients support the ability to determine bootstrap information to establish on-demand blockchains and none of the clients support secure management and pinning from Ethereum MainNet. This paper presents Ethereum Private Sidechains and a range of technologies which allow it to deliver on complex sidechain requirements. Ethereum Registration Authorities are presented, which allow entities which have not previously interacted to securely obtain information to bootstrap a sidechain, and a Management and Pinning strategy is described which allows the state of a sidechain to be securely pinned to Ethereum MainNet without compromising privacy.
Staying abroad during their studies is increasingly popular for students. However, there are various challenges for both students and universities. One important question for students is whether or not achievements performed at different universities can be taken into account for either enrolling at a foreign university or for completing the studies at their home university. In addition to university achievements, an increasing proportion of the 195 million students worldwide increasingly receive certificates from MOOCs or other social media services. The integration of such services into university teaching is still in the initial stages and presents some challenges. In this paper we describe the idea to manage all these study achievements worldwide in a blockchain, which might solve the national and international challenges regarding the recognition of student achievements. The aim of this paper is to encourage discussion in the global community instead of presenting a finished concept. Some of the open research questions are: How to ensure student data protection, how to deal with fraud and how to deal with the possibility that students can analytically calculate the easiest way through their studies?
Fadhel Ayed, Marco Battiston, Federico Camerlenghi, Stefano Favaro
Given $n$ samples from a population of individuals belonging to different types with unknown proportions, how do we estimate the probability of discovering a new type at the $(n+1)$-th draw? This is a classical problem in statistics, commonly referred to as the missing mass estimation problem. Recent results by Ohannessian and Dahleh \citet{Oha12} and Mossel and Ohannessian \citet{Mos15} showed: i) the impossibility of estimating (learning) the missing mass without imposing further structural assumptions on the type proportions; ii) the consistency of the Good-Turing estimator for the missing mass under the assumption that the tail of the type proportions decays to zero as a regularly varying function with parameter $α\in(0,1)$. In this paper we rely on tools from Bayesian nonparametrics to provide an alternative, and simpler, proof of the impossibility of a distribution-free estimation of the missing mass. Up to our knowledge, the use of Bayesian ideas to study large sample asymptotics for the missing mass is new, and it could be of independent interest. Still relying on Bayesian nonparametric tools, we then show that under regularly varying type proportions the convergence rate of the Good-Turing estimator is the best rate that any estimator can achieve, up to a slowly varying function, and that minimax rate must be at least $n^{-α/2}$. We conclude with a discussion of our results, and by conjecturing that the Good-Turing estimator is an rate optimal minimax estimator under regularly varying type proportions.
Alexander Mikroyannidis, John Domingue, Michelle Bachler, Kevin Quick
The emergence of Blockchain technology promises to revolutionise not only the financial world, but also lifelong learning in many different ways. Blockchain technology offers opportunities to thoroughly rethink how we find educational content and training services online, how we register and pay for them, as well as how we get accredited for what we have learned and how this accreditation affects our career trajectory. This paper explores the different aspects of lifelong learning that are affected by this new paradigm and describes an ecosystem that places the learner at the centre of the learning process and its associated data. More specifically, we outline the ways that ePortfolios, accreditation and tutoring can evolve within this learner-centred ecosystem and we discuss the various benefits that this evolution bears for lifelong learners.
Thanks to the new global order established after the Second World War and the communication networks that have become widespread. Due to this, the electronic payment systems that have started to be used since the second half of the 20th century in the world and the credit cards called plastic money have started to be widely used in our country since the 80 '. From the beginning of 2000's, it is observed that cash-based transactions are lagging e-money-based transactions. Since the beginning of the 90's the Internet and social media emerged with new media technologies and after 2004, it has become a dominant idea that these environments provide freedom and even create disorder. In the last 5-6 years we have seen the trade of crypto currencies like Bitcoin. Bitcoin is a method of payment that people use for their purchases based on mutual trust, without an authority issuing it. It works independently of the state authority and the banking system. From this point of view, it is seen as the reflection of freedom originally envisaged for the internet environment. In this context, the question of how bitcoin systems are perceived, and the level of entrepreneurship are issues that needs to be investigated. In this study, a survey was conducted to measure the level of entrepreneurship of bitcoin miners, buyers and sellers. Twitter users were selected for the sample. The research is designed to examine the impact of entrepreneurship motivated by investors' interest in entering the arena that is said to be quite new and risky, and which sub-factors may dominate, which deals with bitcoin and similar crypto currencies. The findings show that users who are interested in mining, buying-selling and trading have very high level of entrepreneurial points.
Cryptocurrencies have recently experienced a new wave of price volatility and interest; activity within social media communities relating to cryptocurrencies has increased significantly. There is currently limited documented knowledge of factors which could indicate future price movements. This paper aims to decipher relationships between cryptocurrency price changes and topic discussion on social media to provide, among other things, an understanding of which topics are indicative of future price movements. To achieve this a well-known dynamic topic modelling approach is applied to social media communication to retrieve information about the temporal occurrence of various topics. A Hawkes model is then applied to find interactions between topics and cryptocurrency prices. The results show particular topics tend to precede certain types of price movements, for example the discussion of 'risk and investment vs trading' being indicative of price falls, the discussion of 'substantial price movements' being indicative of volatility, and the discussion of 'fundamental cryptocurrency value' by technical communities being indicative of price rises. The knowledge of topic relationships gained here could be built into a real-time system, providing trading or alerting signals.
The Bitcoin cryptocurrency records its transactions in a public log called the blockchain. Its security rests critically on the distributed protocol that maintains the blockchain, run by participants called miners. Conventional wisdom asserts that the mining protocol is incentive-compatible and secure against colluding minority groups, that is, it incentivizes miners to follow the protocol as prescribed. We show that the Bitcoin mining protocol is not incentive-compatible. We present an attack with which colluding miners' revenue is larger than their fair share. The attack can have significant consequences for Bitcoin: Rational miners will prefer to join the attackers, and the colluding group will increase in size until it becomes a majority. At this point, the Bitcoin system ceases to be a decentralized currency. Unless certain assumptions are made, selfish mining may be feasible for any coalition size of colluding miners. We propose a practical modification to the Bitcoin protocol that protects Bitcoin in the general case. It prohibits selfish mining by a coalition that command less than 1/4 of the resources. This threshold is lower than the wrongly assumed 1/2 bound, but better than the current reality where a coalition of any size can compromise the system.
This paper presents a comprehensive survey of the existing blockchain protocols for the Internet of Things (IoT) networks. We start by describing the blockchains and summarizing the existing surveys that deal with blockchain technologies. Then, we provide an overview of the application domains of blockchain technologies in IoT, e.g., Internet of Vehicles, Internet of Energy, Internet of Cloud, Edge computing, etc. Moreover, we provide a classification of threat models, which are considered by blockchain protocols in IoT networks, into five main categories, namely identity-based attacks, manipulation-based attacks, cryptanalytic attacks, reputation-based attacks, and service-based attacks. In addition, we provide a taxonomy and a side-by-side comparison of the state-of-the-art methods toward secure and privacy-preserving blockchain technologies with respect to the blockchain model, specific security goals, performance, limitations, computation complexity, and communication overhead. Based on the current survey, we highlight open research challenges and discuss possible future research directions in the blockchain technologies for IoT.
The current global financial market is witnessing the activation of cryptocurrency as a payment instrument and a means of accumulation. However, the risks of money laundering, terrorism financing and tax evasion that cryptocurrency transactions imply lead to the need to implement their state regulation, an important component of which is tax control.Therefore, the purpose of the article is to substantiate the value orientations when forming the system of cryptocurrency transactions tax control in Ukraine taking the positive experience of developed countries into account. The scientific results of the study consist in the emphasizing structural, functional, systemic and institutional approaches to understanding tax control, which became the basis for identifying the features of cryptocurrency transactions as a tax control object.It was revealed that the lack of personalization of the agreement parties, the relatively high level of information security, free international turnover and a decentralized payment system are the factors of the cryptocurrency market further development. On the other hand, this leads to the loss of tax revenues for Ukrainian budgetary system, taking into account the forecasted trends in the development of the cryptocurrency market by 2022 through methods of sums, least squares and expert estimates. Given the institutional approach to the understanding of tax control, an institutional structure of the cryptocurrency transactions tax control in Ukraine is proposed.It is established that domestic state institutions are able to carry out tax control over these transactions. It is also determined that introducing fiscal control will result in the receipt of additional revenues by budgets, reduction of shadow economy, counteraction to cybercrime and terrorism financing.The practical importance of the results is in the need to form an effective system of cryptocurrency transactions tax control as a function of public administration.It has been determined that transactions on cryptocurrency supply, on the determining exchange rates and transactions on cryptocurrency disposal should be an object of tax control in Ukraine. Mining transactions, receipt of income (profits) in the cryptocurrency are subject to general taxes, depending on the taxpayer’s legal status, in particular, personal income tax, corporate income tax and a unified social tax (UST). Taking into account the EU recommendations on the non-application of value added tax in the cryptocurrency transactions taxation, it is not appropriate to implement it in this area. Establishing tax control over cryptocurrency transactions will expand the powers of state authorities that are empowered to control observing financial discipline by economic agents in Ukraine and the financial capabilities of state and local budgets.
Purpose The purpose of this paper is to highlight the intelligence and investigatory challenges experienced by law enforcement agencies in discovering the identity of illicit Bitcoin users and the transactions that they perform. This paper proposes solutions to assist law enforcement agencies in piecing together the disparate and complex technical, behavioural and criminological elements that make up cybercriminal offending. Design/methodology/approach A literature review was conducted to highlight the main law enforcement challenges and discussions and examine current discourse in the areas of anonymity and attribution. The paper also looked at other research and projects that aim to identify illicit transactions involving cryptocurrencies and the darknet. Findings An optimal solution would be one which has a predictive capability and a machine learning architecture which automatically collects and analyses data from the Bitcoin blockchain and other external data sources and applies search criteria matching, indexing and clustering to identify suspicious behaviours. The implementation of a machine learning architecture would help improve results over time and would be less manpower intensive. Cyber investigators would also receive intelligence in a format and language that they understand and it would allow for intelligence-led and predictive policing rather than reactive policing. The optimal solution would be one which allows for intelligence-led, predictive policing and enables and encourages information sharing between multiple stakeholders from the law enforcement, financial intelligence units, cyber security organisations and fintech industry. This would enable the creation of red flags and behaviour models and the provision of up-to-date intelligence on the threat landscape to form a viable intelligence product for law enforcement agencies so that they can more easily get to the who, what, when and where. Originality/value The development of a functional software architecture that, in theory, could be used to detected suspicious illicit transactions on the Bitcoin network.
We examine the stylized facts of eight forms of cryptocurrencies representing almost 70% of cryptocurrency market capitalization. In particular, the empirical results show that (1) there exists heavy tails for all the returns of cryptocurrencies; (2) the autocorrelations for returns decay quickly, while the autocorrelations for absolute returns decay slowly; (3) returns of cryptocurrencies display strong volatility clustering and leverage effects; (4) Hurst exponent for volatility is more volatile than that of the returns, while they all suggest the long-range dependence phenomena; and (5) there exists power-law correlation between price and volume.
Proof-of-Work based blockchain wastes an enormous amount of electricity and requires expensive mining equipment. This phenomenon is getting worse and worse. We propose a new consensus protocol for cryptocurrency built on top of Bitcoin protocol, which combines Proof-of-Work component with our new algorithm Proof-of-Contribution(PoC). PoC algorithm reduces the energy consumption for Bitcoin mining by rewarding the calculation difficulty of a cryptographic puzzle. Further, when miners no longer get block rewards, they receive difficulty rewards along with the regular mining fee which motivates mining. We explored different attacking scenarios and show that the network resilient to these attacks is comparable to Poof-of-Work(PoW). Finally, we designed two experiments to simulate mining and detect the changes of difficulty to prove PoC offering a new cryptocurrency algorithm which is energy-efficient.
Yan Zhu, Yao Qin, Guohua Gan, Yang Shuai · 5 authors
In this paper we focus on a new generation of secure resource sharing platform in a decentralized blockchain environment with flexible and diverse permission management, as well as verifiable and transparent access process. To do it, we present a new Transaction-based Access Control (TBAC) platform which integrates the standard attribute-based access control (ABAC) model and the blockchain system. In this platform, four types of transactions and Bitcoin-type cryptographic scripts are presented to describe the TBAC access control procedure corresponding to subject registration, object escrowing and publication, access request and grant. We also present a cryptosystem associated with TBAC (CryptoTBAC) for ensuring secure attribute-exchanging and decision-making of dynamic policy. We evaluate the security of CryptoTBAC from three aspects: transaction, authorization, and decision-making security.
There are several studies that propose identity management that utilizes blockchain technology. In Ethereum, the main programmable blockchain system, data on a blockchain are saved as encoded binaries for executing automatic verification. To decode a binary, users need to know the application binary interfaces (ABI) that describes the data structure of the registered information. However, the manner by which ABI are shared in the current blockchain protocol is opaque. To resolve this problem, we describe a new protocol for embedding the ABI on a blockchain transaction when a registrant registers information. Our method enables users to read registered data with information on the blockchain alone, and it guarantees transparency without requiring users to trust third parties.
In many countries, sustainable public procurement is a powerful tool to reflect on national strategic intentions and promote scientific and technological innovation. Based on the perspective of an institutional structure, we filtered out the core policies. Using policy bibliometrics, we analyzed Chinese public procurement policies on promoting scientific and technological innovation, revealed policy-making characteristics, and concluded that the Ministry of Finance should appropriately decentralize the policy-making work to other relevant agencies of the State Council. This article compares the main policy tools from four dimensions in China, the U.S., the United Kingdom, Japan, Germany, France, and South Korea. We issued these pertinent strategies: establishing the vendor database for small and medium enterprises, developing a grade system and the post-evaluation system, formulating detailed implementation methods for high-tech products (services), and carrying out classification management for imported products. For sustainable public procurement policies on promoting scientific and technological innovation, this article provides an effective reference to organize the agencies and formulate the detail measures. This article’s research framework could be applied to analyze other industry policies.
Digital identity is the cornerstone of a digital economy. However, proving identity remotely is difficult to do. To complicate things further, identity is usually not a global, absolute construct, but the information shared with different parties differs, based on the relationship to the user. Therefore, a viable solution for digital identity should enable users to have full control over their personal information and share only the information that they wish to share with each service. Blockchain technology can help to realize a self-sovereign identity that puts the user in control of her information, by enabling a decentralized way to handle public key infrastructure. In the current contribution, we present the Sora identity system, which is a mobile app that utilizes blockchain technology to create a secure protocol for storing encrypted personal information, as well as sharing verifiable claims about personal information.
This paper discusses the mining-trading of cryptocurrency in Islamic law as a digital asset that has recently been traded in cyberspace. The value of cryptocurrency is soaring and fluctuation and it is influenced by the demand of buying and selling. Indodax.com is the official digital asset site in Indonesia that trades more than 13 digital currencies. As we know, digital currencies are not electronic money, even though the characteristic is similar. Starting from this, I analyze whether cryptocurrency is worthy of being value as money that has a certain value. Until now, the Indonesian government through Bank Indonesia has published regulation Number 16/8/PBI/ 2014, which explicitly prohibits using bitcoin and altcoin on financial transactions. Otherwise, MUI (Indonesian Ulema Council) has not issued a fatwa yet related to cryptocurrency. From here, I focuse on this study to the law of cryptocurrency in Islamic law. Bitcoin has advantages and disadvantages. Among its advantages are the user can use exchange or transaction without third service (bank), and it can be traded in merchandise shops. But, the disadvantages of bitcoin are mach more, such as fluctuating value every times, it is not listed as a commodity, it is not watched by Financial Services Authority (OJK), it presents the element of gharar (uncertainty) and maysir (gambling or bet), which makes it possible to be used for money laundering and drugs. On the other hand, until now, the Indonesian people have not considered that bitcoin as a treasure like gold or silver
In the past, the improvement of digital copyright protection system based on digital watermarking mainly focused on algorithms, while generation and storage of the watermark information was ignored. In this paper, a new design scheme of copyright management system based on digital watermarking and its information, such as blockchain, is proposed, which combines digital watermarking, blockchain, perceptual hash function, Quick Response(QR) code, and InterPlanetary File System(IPFS). Among them, blockchain is used to securely store watermark information and provide timestamp authentication for multiple watermarks (multiple copyrights) to confirm the creation order. Perceptual hash function is used to generate hash value based on the structure information of images, that watermark information can be confirmed without the original image. QR code is used to generate QR code images containing image hash and copyright information as watermark images to improve robustness and capacity of digital watermarking; IPFS is used to store and distribute watermarked images without a centralized server. This scheme can enhance the effectiveness of digital watermarking technology in the field of copyright protection. In this way, use P2P network to integrate and complete copyright management and distribution of copyrighted works without requiring a trusted third party. Nodes rely on cryptography to confirm the identity of each other and ensure the security of information. It can reduce information leakage, data destruction and other risks caused by collapse of the centralized system in the past. This improves the security and transparency of information, and speeds up the distribution of copyrighted works to facilitate circulation in the network. This scheme can also improve copyright protection of multiple creations. Combine blockchain and multiple digital watermarks to record copyright information of every copyright owner in the authoring process and fully prove this information. In order to protect the legitimate rights and interests of each copyright owner.
Advanced Steganography and Watermarking Techniques