The objective of this paper is to describe the contemporary issues that supply chains face using the information sharing dimension and analyze blockchain technology’s capabilities to address these issues. We discuss select issues in managing contemporary supply chains from an information sharing perspective namely, information coordination challenges, effect of product and service manifestation on information complexity, effect of customer demand manifestation on information flow, outsourcing and globalization effects on information flow, and new emerging threats to supply chains by affecting information vulnerability. These issues are further categorized into- confidentiality and trust issues, inability to share information between supply chain partners, limitations of IT systems and lack of data standards. To address these issues, a unifying framework describing the applicability of blockchain has been presented that will guide companies in designing and implementing potential blockchain solutions to address issues in information exchange among supply chain partners. Blockchain based research is in nascent stages and this paper aims to add to this emerging research paradigm by analyzing blockchain technology through the information sharing dimension of supply chains. (this record is metadata only)
Jan 17, 2018·Peter Krafft, Nicolás Della Penna, Alex Pentland. (2018). An Experimental Study of Cryptocurrency Market Dynamics. ACM CHI Conference on Human Factors in Computing Systems (CHI)
P. M. Krafft, Nicolás Della Penna, Alex Sandy Pentland
As cryptocurrencies gain popularity and credibility, marketplaces for cryptocurrencies are growing in importance. Understanding the dynamics of these markets can help to assess how viable the cryptocurrnency ecosystem is and how design choices affect market behavior. One existential threat to cryptocurrencies is dramatic fluctuations in traders' willingness to buy or sell. Using a novel experimental methodology, we conducted an online experiment to study how susceptible traders in these markets are to peer influence from trading behavior. We created bots that executed over one hundred thousand trades costing less than a penny each in 217 cryptocurrencies over the course of six months. We find that individual "buy" actions led to short-term increases in subsequent buy-side activity hundreds of times the size of our interventions. From a design perspective, we note that the design choices of the exchange we study may have promoted this and other peer influence effects, which highlights the potential social and economic impact of HCI in the design of digital institutions.
This paper presents the implementation of an interactive Zero Knowledge Password authentication scheme for commercial Web sites. In this scheme, a legitimate prover (client) can exchange a secret code (password) with a remote skeptic (server), in order to reveal his/her identification. Based on the validity of the secret code the skeptic then allows the prover to login to the site and access the web services. This paper introduces a protocol that integrates the concepts of Discrete Logarithm Problem (DLP) and Zero-Knowledge Proofs (ZKP). The protocol consists of three entities, namely, the prover, the skeptic, and the facilitator who interact with one another to generate the secret code. When tested, the time to carry out various operations related to this protocol was reasonably small (under 4 seconds). Our scheme is resistant to man-in-the-middle attack and discourages replaying previously intercepted secret codes. We also propose two modifications to our basic scheme to make it resistant against the attack on Integrity and Denial of Service attack (DOS).
A peer-to-peer system of blockchain, originally started for a cryptocurrency Bitcoin, has caused major disruptions in the stock market. It has affected many businesses if not all, but its significance in the financial world is magnanimous. Historical data (daily rates) for the past 23 months are analyzed to understand the market size, market capitalization and price volatility for Bitcoin. Time series data and financial model are applied to realize the shocks. Monte Carlo simulation is applied to assess the dynamic structure of Bitcoin. With greater volume and activity, the banks and financial intermediaries may become outdated, and the middleman will have no place. It seems like a distant thought, but the facts are pointing toward its reality.
The paper proves the validity of studying cryptocurrency as a cultural phenomenon. According to the Fundamentals of State Cultural Policy, culture is a resource of the social and economic development of the country, therefore, examining the economic aspects of the society is of great importance to cultural scientists. The possibility of dealing with cryptocurrency as a cultural element is confirmed by the following statements. Cryptocurrency refers to the economic culture of a society. The cryptocurrency impact is covered in mass media which constitute the cultural institution. In addition, cryptocurrency is consolidated in culture through the specialized exhibitions supported by public cultural agencies. The paper defines the promising trends in researches identifying the capacity of the virtual reality in the field of cultural patterns development. The authors note that studying cryptocurrency as a part of virtual reality will allow one to determine the mechanisms, borders, and technologies of this type of reality.
Open access
Security, Politics, and Digital Transformation
Library Science and Information
Innovations in Education and Learning Technologies
In multi-prover interactive proofs (MIPs), the verifier is usually non-adaptive. This stems from an implicit problem which we call ``contamination'' by the verifier. We make explicit the verifier contamination problem, and identify a solution by constructing a generalization of the MIP model. This new model quantifies non-locality as a new dimension in the characterization of MIPs. A new property of zero-knowledge emerges naturally as a result by also quantifying the non-locality of the simulator.
In multi-prover interactive proofs (MIPs), the verifier can provide non-local resources for the provers intrinsically. In most cases, this is undesirable. Existing proofs of soundness do not account for the verifier's non-local potential. We show that this may be a problem for many MIPs. We provide a solution by constructing a generalization of the MIP model, of which standard MIPs are a special case. This new model accounts for both the prover and the verifier's non-local correlations. A new property of multi-prover zero-knowledge naturally emerges as a result.
BlockChain (BC) immutability ensures BC resilience against modification or removal of the stored data. In large scale networks like the Internet of Things (IoT), however, this feature significantly increases BC storage size and raises privacy challenges. In this paper, we propose a Memory Optimized and Flexible BC (MOF-BC) that enables the IoT users and service providers to remove or summarize their transactions and age their data and to exercise the "right to be forgotten". To increase privacy, a user may employ multiple keys for different transactions. To allow for the removal of stored transactions, all keys would need to be stored which complicates key management and storage. MOF-BC introduces the notion of a Generator Verifier (GV) which is a signed hash of a Generator Verifier Secret (GVS). The GV changes for each transaction to provide privacy yet is signed by a unique key, thus minimizing the information that needs to be stored. A flexible transaction fee model and a reward mechanism is proposed to incentivize users to participate in optimizing memory consumption. Qualitative security and privacy analysis demonstrates that MOF-BC is resilient against several security attacks. Evaluation results show that MOF-BC decreases BC memory consumption by up to 25\% and the user cost by more than two orders of magnitude compared to conventional BC instantiations.
Blockchain design involves many tradeoffs, and much debate has focused on tradeoffs related to scaling parameters such as blocksize. To address some of the confusion around this subject, we present a probability proof of the DCS Triangle. We use the triangle to show decentralized consensus systems, like blockchains, can have Decentralization, Consensus, or Scale, but not all three properties simultaneously. We then describe two methods for getting around the limitations suggested by the triangle.
The state-of-the-art mobile edge applications are generating intense traffic and posing rigorous latency requirements to service providers. While resource sharing across multiple service providers can be a way to maximize the utilization of limited resources at the network edge, it requires a centralized repository maintained by all parties for service providers to share status. Moreover, service providers have to trust each other for resource allocation fairness, which is difficult because of potential conflicts of interest. We propose EdgeChain, a blockchain-based architecture to make mobile edge application placement decisions for multiple service providers. We first formulate a stochastic programming problem minimizing the placement cost for mobile edge application placement scenarios. Based on our model, we present a heuristic mobile edge application placement algorithm. As a decentralized public ledger, the blockchain then takes the logic of our algorithm as the smart contract, with the consideration of resources from all mobile edge hosts participating in the system. The algorithm is agreed by all parties and the results will only be accepted by majority of the mining nodes on the blockchain. When a placement decision is made, an edge host meeting the consumer's latency and budget requirements will be selected at the lowest cost. All placement transactions are stored on the blockchain and are traceable by every mobile edge service provider and application vendor who consumes resources at the mobile edge.
Dana Országhová, Radomíra Hornyák Gregáňová, Viera Papcunová
Changes in the socio-economic conditions of countries initiate modifications in the management of its economic and social processes, which are also followed by conversions in the public administration. At the same time, they are also looking for the concepts of rational organization and effective management of the public administration. The public administration of the Slovak Republic is created by local self-government and regional selfgovernment. Municipalities represent the local self-government bodies. The effective conditions of the municipalities are creating the effective setting of its financing. Until 2004 the financing of municipalities was determined annually by the state budget act and for the municipalities distributed from the state budget a share of the tax of personal income, which consisted of three taxes: tax of personal income, tax of the corporation income and road tax. In 2005 the fiscal decentralization took place in Slovakia as a part of the consolidation of public finances, resulting in a new way of financing municipalities. The basis of the new financing system of municipalities was to determine the tax of personal income as a single share tax, in particular, because the dynamics of the income of this tax was expected to grow even in the medium term. The objective of the paper is to evaluate changes and trends in the financial management of municipalities based on selected fiscal indicators within the period 1993 -2015.
In this dissertation we will present the Bitcoin and its technology and is supporting feature as a success factor for innovation and entrepreneurship. We will first demonstrate that Bitcoin is a currency and present its history and technology. Then from our literature researches and the interview we have conducted we will try to answer our problematic: Is Bitcoin and the Blockchain supporting entrepreneurship and innovation? Finally after crossing the theoretical and academic lectures with the testimony of the real actors we will present our conclusion and recommendation to the lectors.
Shelly Grossman, Ittai Abraham, Guy Golan-Gueta, Yan Michalevsky · 7 authors
Callbacks are essential in many programming environments, but drastically\ncomplicate program understanding and reasoning because they allow to mutate\nobject's local states by external objects in unexpected fashions, thus breaking\nmodularity. The famous DAO bug in the cryptocurrency framework Ethereum,\nemployed callbacks to steal $150M. We define the notion of Effectively Callback\nFree (ECF) objects in order to allow callbacks without preventing modular\nreasoning.\n An object is ECF in a given execution trace if there exists an equivalent\nexecution trace without callbacks to this object. An object is ECF if it is ECF\nin every possible execution trace. We study the decidability of dynamically\nchecking ECF in a given execution trace and statically checking if an object is\nECF. We also show that dynamically checking ECF in Ethereum is feasible and can\nbe done online. By running the history of all execution traces in Ethereum, we\nwere able to verify that virtually all existing contracts, excluding the DAO or\ncontracts with similar known vulnerabilities, are ECF. Finally, we show that\nECF, whether it is verified dynamically or statically, enables modular\nreasoning about objects with encapsulated state.\n
The emergence of distributed ledger technology (DLT) based upon a blockchain data structure, has given rise to new approaches to identity management that aim to upend dominant approaches to providing and consuming digital identities. These new approaches to identity management (IdM) propose to enhance decentralisation, transparency and user control in transactions that involve identity information; but, given the historical challenge to design IdM, can these new DLT-based schemes deliver on their lofty goals? We introduce the emerging landscape of DLT-based IdM, and evaluate three representative proposals: uPort; ShoCard; and Sovrin; using the analytic lens of a seminal framework that characterises the nature of successful IdM schemes.
Digital currencies, such as Bitcoin, have emerged as an alternative form of money, untethered to traditional money and largely unregulated. As such, digital currency represents a wild frontier for investors who might otherwise be shopping for gold or foreign currencies, with serious risks. The present work considers digital currency from a traditional asset pricing perspective. Setting aside risks of seller fraud or currency theft, we examine fluctuation and systematic risk in the price of Bitcoin. From this perspective, Bitcoin does not appear to carry much systematic risk -- despite its high volatility -- and so is a reasonable candidate for inclusion in investors’ portfolios. Some illustrative examples suggest that the optimal amount of Bitcoin to include in investor portfolios may be tiny or instead substantial - as high as 21 percent of total financial assets.
Large-scale rumor spreading could pose severe social and economic damages. The emergence of online social networks along with the new media can even make rumor spreading more severe. Effective control of rumor spreading is of theoretical and practical significance. This paper takes the first step to understand how the blockchain technology can help limit the spread of rumors. Specifically, we develop a new paradigm for social networks embedded with the blockchain technology, which employs decentralized contracts to motivate trust networks as well as secure information exchange contract. We design a blockchain-based sequential algorithm which utilizes virtual information credits for each peer-to-peer information exchange. We validate the effectiveness of the blockchain-enabled social network on limiting the rumor spreading. Simulation results validate our algorithm design in avoiding rapid and intense rumor spreading, and motivate better mechanism design for trusted social networks.
Abstract Materials and structures with negative Poisson’s ratio exhibit a counter-intuitive behaviour. Under uniaxial compression (tension), these materials and structures contract (expand) transversely. The materials and structures that possess this feature are also termed as ‘auxetics’. Many desirable properties resulting from this uncommon behaviour are reported. These superior properties offer auxetics broad potential applications in the fields of smart filters, sensors, medical devices and protective equipment. However, there are still challenging problems which impede a wider application of auxetic materials. This review paper mainly focuses on the relationships among structures, materials, properties and applications of auxetic metamaterials and structures. The previous works of auxetics are extensively reviewed, including different auxetic cellular models, naturally observed auxetic behaviour, different desirable properties of auxetics, and potential applications. In particular, metallic auxetic materials and a methodology for generating 3D metallic auxetic materials are reviewed in details. Although most of the literature mentions that auxetic materials possess superior properties, very few types of auxetic materials have been fabricated and implemented for practical applications. Here, the challenges and future work on the topic of auxetics are also presented to inspire prospective research work. This review article covers the most recent progress of auxetic metamaterials and auxetic structures. More importantly, several drawbacks of auxetics are also presented to caution researchers in the future study.
In this paper, we investigate the use of decentralized blockchain mechanisms for delivering transparent, secure, reliable, and timely energy flexibility, under the form of adaptation of energy demand profiles of Distributed Energy Prosumers, to all the stakeholders involved in the flexibility markets (Distribution System Operators primarily, retailers, aggregators, etc.). In our approach, a blockchain based distributed ledger stores in a tamper proof manner the energy prosumption information collected from Internet of Things smart metering devices, while self-enforcing smart contracts programmatically define the expected energy flexibility at the level of each prosumer, the associated rewards or penalties, and the rules for balancing the energy demand with the energy production at grid level. Consensus based validation will be used for demand response programs validation and to activate the appropriate financial settlement for the flexibility providers. The approach was validated using a prototype implemented in an Ethereum platform using energy consumption and production traces of several buildings from literature data sets. The results show that our blockchain based distributed demand side management can be used for matching energy demand and production at smart grid level, the demand response signal being followed with high accuracy, while the amount of energy flexibility needed for convergence is reduced.
Bitcoin, as well as many of its successors, require the whole transaction record to be reliably acquired by all nodes to prevent double-spending. Recently, many blockchains have been proposed to achieve scale-out throughput by letting nodes only acquire a fraction of the whole transaction set. However, these schemes, e.g., sharding and off-chain techniques, suffer from a degradation in decentralization or the capacity of fault tolerance. In this paper, we show that the complete set of transactions is not a necessity for the prevention of double-spending if the properties of value transfers is fully explored. In other words, we show that a value-transfer ledger like Bitcoin has the potential to scale-out by its nature without sacrificing security or decentralization. Firstly, we give a formal definition for the value-transfer ledger and its distinct features from a generic database. Then, we introduce an off-chain based scheme with a shared main chain for consensus and an individual chain for each node for recording transactions. A locally executable validation scheme is proposed with uncompromising validity and consistency. A beneficial consequence of our design is that nodes will spontaneously try to reduce their transmission cost by only providing the transactions needed to show that their transactions are double-spending-proof. As a result, the network is sharded as each node only acquires part of the transaction record and a scale-out throughput could be achieved, which we call "spontaneous sharding".
Hany F. Atlam, Ahmed Alenezi, Raid Khalid Hussein, Gary Wills
The Internet of Things (IoT) has spread into multiple dimensions that incorporate different physical and virtual things. These things are connected together using different communication technologies to provide unlimited services. These services help not only to improve the quality of our daily lives, but also to provide a communication platform for increasing object collaboration and information sharing. Like all new technologies, the IoT has many security challenges that stand as a barrier to the successful implementation of IoT applications. These challenges are more complicated due to the dynamic and heterogeneous nature of IoT systems. However, authentication and access control models can be used to address the security issue in the IoT. To increase information sharing and availability, the IoT requires a dynamic access control model that takes not only access policies but also real-time contextual information into account when making access decisions. One of the dynamic features is the security risk. This paper proposes an Adaptive Risk-Based Access Control (AdRBAC) model for the IoT and discusses its validation using expert reviews. The proposed AdRBAC model conducts a risk analysis to estimate the security risk value associated with each access request when making an access decision. This model has four inputs/risk factors: user context, resource sensitivity, action severity and risk history. These risk factors are used to estimate a risk value associated with the access request to make the access decision. To provide the adaptive features, smart contracts will be used to monitor the user behaviour during access sessions to detect any malicious actions from the granted users. To validate and refine the proposed model, twenty IoT security experts from inside and outside the UK were interviewed. The experts have suggested valuable information that will help to specify the appropriate risk factors and risk estimation technique for implantation of the AdRBAC model.
Homomorphic Cryptography raised as a new solution used in electronic voting systems. In this research, Fully Homomorphic encryption used to design and implement an e-voting system. The purpose of the study is to examine the applicability of Fully Homomorphic encryption in real systems and to evaluate the performance of fully homomorphic encryption in evoting systems. Most of homomorphic cryptography evoting systems based on additive or multiplicative homomorphic encryption. In this research, fully homomorphic encryption used to provide both operations additive and multiplication, which ease the demonstration of none interactive zero-knowledge proof NIZKP. The proposed e-voting system achieved most of the important security issues of the internet-voting systems such as eligibility, privacy, accuracy, verifiability, fairness, and others. One of the most important properties of the implemented internet voting system its applicability to work on cloud infrastructure, while preserving its security characteristics. The implementation is done using homomorphic encryption library HELib. Addition and multiplication properties of fully homomorphic encryption were used to verify the correctness of vote structure as a NIZKP, and for calculating the results of the voting process in an encrypted way. The results show that the implemented internet voting system is secure and applicable for a large number of voters up to 10 million voters.
Open access
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
<em>This paper aims to identify the practices involved in the formation of smart contracts and the limitations that are faced by the organizations through development of smart contracts in business. The Smart contract is developed based on specific criteria in the business. The smart chain in the business identify the block chains that are developed in the business to resolve different financial issues in the company. In this report, the elements of smart contracts are evaluated and analyzed along with a discussion of previous researchers on the same criteria. This study identifies that smart contracts become essential for business practices with development of technology. The form of smart contracts has captured the attention of legal attorney and its impact on contract law of business. This report implements the descriptive methodology approach in which the secondary data is analyzed to identify the formation of smart contracts and its liability on business. Additionally, the research data is analyzed through secondary qualitative analysis. </em>
We examine blockchain technologies, especially smart contracts, as a platform for decentralized applications. By providing a basis for consensus, blockchain promises to upend business models that presuppose a central authority. However, blockchain suffers from major shortcomings arising from an over-regimented way of organizing computation that limits its prospects. We propose a sociotechnical, yet computational, perspective that avoids those shortcomings. A centerpiece of our vision is the notion of a declarative, violable contract in contradistinction to smart contracts. This new way of thinking enables flexible governance, by formalizing organizational structures; verification of correctness without obstructing autonomy; and a meaningful basis for trust.