One remarkable feature of vehicular ad hoc networks is characterized by an opportunistic communications by means of store-carry-forward message relaying which requires the cooperation of vehicles on the networks. However, we cannot be sure that all vehicles willingly contribute their computing resources to the networks for message forwarding with no rewards for their efforts in real-world scenarios. In addition, unfortunately, there may exist some selfish and greedy node which may not help others but tend to take their own gain. To cope with this challenge, incentive mechanisms are generally considered as the promising solution. In this paper, we design a Bitcoin-based secure and reliable incentive scheme for cooperative vehicular delay tolerant networking services. Bitcoin is the well-known worldwide cryptocurrency and digital payment system whose implementation relies on cryptographic techniques, which makes it possible to develop a practical credit-based incentive scheme on the vehicular networks at a low cost. We also implement Bitcoin transaction scripts to handle our proposed incentive scheme.
Paolo Missier, Shaimaa Bajoudah, Angelo Capossele, Andrea Gaglione · 5 authors
Internet of Things (IoT) data are increasingly viewed as a new form of massively distributed and large scale digital assets, which are continuously generated by millions of connected devices. The real value of such assets can only be realized by allowing IoT data trading to occur on a marketplace that rewards every single producer and consumer, at a very granular level. Crucially, we believe that such a marketplace should not be owned by anybody, and should instead fairly and transparently self-enforce a well defined set of governance rules. In this paper we address some of the technical challenges involved in realizing such a marketplace. We leverage emerging blockchain technologies to build a decentralized, trusted, transparent and open architecture for IoT traffic metering and contract compliance, on top of the largely adopted IoT brokered data infrastructure. We discuss an Ethereum-based prototype implementation and experimentally evaluate the overhead cost associated with Smart Contract transactions, concluding that a viable business model can indeed be associated with our technical approach.
Decentralised random number generation algorithms suffer from the Last Actor Problem, in which the last participant to reveal their share can manipulate the generated random value by withholding their share. This paper proposes an encrypted share threshold scheme which prevents this attack.
Kampanje javnog prikupljanja sredstava sve su češći način financiranja novih projekata, no dolaze uz otvorena pitanja oko pouzdanosti sudionika i sigurnosti prikupljenih sredstava. Postojanje okruženja u kojem bi ispravno i sigurno funkcioniranje prikupljanja i povrata sredstava bilo garantirano, pogodovalo bi povećanju popularnosti ovog načina financiranja, povećalo interes potencijalnih donatora i ohrabrilo pokretače novih projekata. Tehnologija blok-lanca stvorila je okruženje za nastanak decentraliziranih kriptovaluta, omogućivši obavljanje transakcija bez uključivanja treće strane kao centralnog autoriteta kojemu se vjeruje. Platforma Ethereum, bazirana na tehnologiji blok-lanca, u takvom okruženju u kojem nema potrebe za vjerovanjem trećoj strani, omogućuje definiranje pametnih ugovora koji mogu sadržavati proizvoljnu logiku i pravila za vlasništvo, transakcije i ostalo. Korištenjem pametnih ugovora platforme Ethereum, razvijeno je rješenje za decentralizirano prikupljanje sredstava, uz proširenja koja donatorima pružaju određenu kontrolu nad trošenjem prikupljenih sredstava, kao i mogućnost prekida projekta uz osiguran povratak preostalih sredstava.
Jeremy A. Scher, Michael G. Bayne, Amogh Srihari, Shikha Nangia · 5 authors
The relationship between structure and property is central to chemistry and enables the understanding of chemical phenomena and processes. Need for an efficient conformational sampling of chemical systems arises from the presence of solvents and the existence of non-zero temperatures. However, conformational sampling of structures to compute molecular quantum mechanical properties is computationally expensive because a large number of electronic structure calculations are required. In this work, the development and implementation of the effective stochastic potential (ESP) method is presented to perform efficient conformational sampling of molecules. The overarching goal of this work is to alleviate the computational bottleneck associated with performing a large number of electronic structure calculations required for conformational sampling. We introduce the concept of a deformation potential and demonstrate its existence by the proof-by-construction approach. A statistical description of the fluctuations in the deformation potential due to non-zero temperature was obtained using infinite-order moment expansion of the distribution. The formal mathematical definition of the ESP was derived using the functional minimization approach to match the infinite-order moment expansion for the deformation potential. Practical implementation of the ESP was obtained using the random-matrix theory method. The developed method was applied to two proof-of-concept calculations of the distribution of HOMO-LUMO gaps in water molecules and solvated CdSe clusters at 300 K. The need for large sample size to obtain statistically meaningful results was demonstrated by performing 105 ESP calculations. The results from these prototype calculations demonstrated the efficacy of the ESP method for performing efficient conformational sampling. We envision that the fundamental nature of this work will not only extend our knowledge of chemical systems at non-zero temperatures but also generate new insights for innovative technological applications.
Open access
Advanced Physical and Chemical Molecular Interactions
Modern power systems are rapidly evolving into complex cyber-physical systems. The increasingly complex interaction among different energy entities calls for a secure, efficient, and robust cyber infrastructure. As an emerging distributed computing technology, Blockchain provides a secure environment to support such interactions. This paper gives a prospective on using Blockchain as a secure, distributed cyber infrastructure for the future grid. Firstly, the basic principles of Blockchain and its state-of-the-art are introduced. Then, a Blockchain based smart grid cyber-physical infrastructure model is proposed. Afterwards, some promising application domains of Blockchain in future grids are presented. Following this, some potential challenges are discussed.
Gihan J. Mendis, Yifu Wu, Jin Wei, Moein Sabounchi · 5 authors
Thanks to the advances in machine learning, data-driven analysis tools have become valuable solutions for various applications. However, there still remain essential challenges to develop effective data-driven methods because of the need to acquire a large amount of data and to have sufficient computing power to handle the data. In many instances these challenges are addressed by relying on a dominant cloud computing vendor, but, although commercial cloud vendors provide valuable platforms for data analytics, they can suffer from a lack of transparency, security, and privacy-perservation. Furthermore, reliance on cloud servers prevents applying big data analytics in environments where the computing power is scattered. To address these challenges, a decentralize, secure, and privacy-preserving computing paradigm is proposed to enable an asynchronized cooperative computing process amongst scattered and untrustworthy computing nodes that may have limited computing power and computing intelligence. This paradigm is designed by exploring blockchain, decentralized learning, homomorphic encryption, and software defined networking(SDN) techniques. The performance of the proposed paradigm is evaluated via different scenarios in the simulation section.
Blockchain accounting is one of the most welcomed technologies of this new era. The blockchain is a public ledger where lacks of people are connected to that ledger. Blockchain also called as distributed ledger, could help accountant to gain clearly over the available financial resources and obligations of their organization and to utilize available resources, concentrate on planning and valuation, rather than the record keeping .Blocked chain which was originally developed in2009 to record crypto currency transactions. Blockchain technology has the potential to upend entire industries. Especially the financial sector may undergo disruptive change. Although this technology caught the attention of many of the largest financial institutions, use cases still remain in the experimental phase.
Gihan J. Mendis, Moein Sabounchi, Wei Jin, Rigoberto Roche
Deep learning algorithms have recently gained attention due to their inherent capabilities and the application opportunities that they provide. Two of the main reasons for the success of deep learning methods are the availability of processing power and big data. Both of these two are expensive and rare commodities that present limitations to the usage and implementation of deep learning. Decentralization of the processing and data is one of the most prevalent solutions for these issues. This paper proposes a cooperative decentralized deep learning architecture. The contributors can train deep learning models with private data and share them to the cooperative data-driven applications initiated elsewhere. Shared models are fused together to obtain a better model. In this work, the contributors can both design their own models or train the models provided by the initiator. In order to utilize an efficient decentralized learning algorithm, blockchain technology is incorporated as a method of creating an incentive-compatible market. In the proposed method, Ethereum blockchain's scripting capabilities are employed to devise a decentralized deep learning mechanism, which provides much higher, collective processing power and grants access to large amounts of data, which would be otherwise inaccessible. The technical description of the mechanism is described and the simulation results are presented.
G. Balachandran, Grégoire Mallard, Olufunmilayo B. Arewa, Lucio Baccaro · 9 authors
This chapter attempts a broad analytical compass for surveying the main actors, institutions and instruments governing our world. Despite its seeming ubiquity, governance is a relatively new expression in this context suggestive both of new modes of exercising power, and an enhanced focus on ordering a world undergoing rapid change. Speaking generally governance may be understood as the exercise of power organized around multiple dispersed sites operating through transnational networks of actors, public as well as private, and national, regional as well as local. The turn to governance is often held to be coeval if not conjoined to profound changes in the meaning and nature of government associated with the ascendancy of ‘neo-liberal’ ideas and precepts. This has had significant implications for how governance tends to be understood. Critics associate it directly with the changing role of states in the economic and social sphere. Transnational governance, in particular, is criticized for foregrounding the priorities of corporate investors often to the detriment of social or environmental goals, subordinating principles of ‘comparative’ or ‘cooperative’ advantage to ‘competitive’ advantage, and promoting microregulatory forms of regulation over strategic or structurally-focused interventions (such as industrial policy). Associated shifts trace states’ powers, otherwise a touchstone of sovereignty, being increasingly negotiated with transnational private actors and international financial institutions (IFIs), and placed under external jurisdictions. The turn to governance tends also to framed, whether directly or directly, justifiably or otherwise, alongside cuts in the public provisioning of health, education, housing, and social expenditures wherever they may have taken place, a parallel proliferation of managerial controls, and to governments contracting out public services to private and quasi-private agencies, or relinquishing them to the voluntary sector. At the risk of oversimplifying its critics’ views, if modern governments describe rule by/of citizens, governance describes rule over subjects. This chapter maps a rather more fluid and differentiated landscape of governance across the five areas it surveys, i.e. finance, investment, trade, labor and environment. In finance, while regulation may appear to have become more transnational and to an extent even voluntary, deregulatory outcomes have reconfigured the nature of risk and the cognitive and policy frameworks for dealing with it. At the same time a growing risk of states having to foot the ultimate bill may still become a point of departure for more differentiated regulatory approaches. On the other hand, not only are environmental agreements continued to be implemented and enforced at national and sub-national scales, the ascendency of market interventions and transnational institutions here has taken place in parallel with—and sometimes through mutual cooptation of—other kinds of interventions including those for promoting decentralization and community control over resources. Trends in labor regulation may also reflect individual state choices more than direct transnational pressures, or run contrary to the preferences of specialized international organizations in the domain. Even in the controversial sphere of investment treaties, there is considerable ongoing fluidity with regard to norms, jurisdiction, and actors within and between national and international arenas. Thus, upon closer inspection and with the benefit of a more domain-specific approach, we may not necessarily observe a sweeping or uniform shift, but more a mosaic of regulatory frameworks, quite disparate trends with regard to their negotiation, implementation and impact, and a future rife with possibilities.
This paper presents LinBFT, a novel Byzantine fault tolerance (BFT) protocol for blockchain systems that achieves amortized O(n) communication volume per block under reasonable conditions (where n is the number of participants), while satisfying determinist guarantees on safety and liveness. This significantly improves previous results, which either incurs quadratic communication complexity, or only satisfies safety in a probabilistic sense. LinBFT is based on the popular PBFT protocol, and cuts down its $O(n^4)$ complexity with three tricks, each by $O(n)$: linear view change, threshold signatures, and verifiable random functions. All three are known, i.e., the solutions are right in front of our eyes, and yet LinBFT is the first $O(n)$ solution with deterministic security guarantees. Further, LinBFT also addresses issues that are specific to permission-less, public blockchain systems, such as anonymous participants without a public-key infrastructure, proof-of-stake with slashing, rotating leader, and a dynamic participant set. In addition, LinBFT contains no proof-of-work module, reaches consensus for every block, and tolerates changing honesty of the participants for different blocks.
Regio A. Michelin, Ali Dorri, Roben Castagna Lunardi, Marco Steger · 7 authors
There is increased interest in smart vehicles acting as both data consumers and producers in smart cities. Vehicles can use smart city data for decision-making, such as dynamic routing based on traffic conditions. Moreover, the multitude of embedded sensors in vehicles can collectively produce a rich data set of the urban landscape that can be used to provide a range of services. Key to the success of this vision is a scalable and private architecture for trusted data sharing. This paper proposes a framework called SpeedyChain, that leverages blockchain technology to allow smart vehicles to share their data while maintaining privacy, integrity, resilience and non-repudiation in a decentralized, and tamper-resistant manner. Differently from traditional blockchain usage (e.g., Bitcoin and Ethereum), the proposed framework uses a blockchain design that decouples the data stored in the transactions from the block header, thus allowing for fast addition of data to the blocks. Furthermore, an expiration time for each block to avoid large sized blocks is proposed. This paper also presents an evaluation of the proposed framework in a network emulator to demonstrate its benefits.
Blockchain and Cryptocurrencies are gaining unprecedented popularity and understanding. Meanwhile, Ethereum is gaining a significant popularity in the blockchain community, mainly due to the fact that it is designed in a way that enables developers to write smart contract and decentralized applications (Dapps). This new paradigm of applications opens the door to many possibilities and opportunities. However, the security of Ethereum smart contracts has not received much attention; several Ethereum smart contracts malfunctioning have recently been reported. Unlike many previous works that have applied static and dynamic analyses to find bugs in smart contracts, we do not attempt to define and extract any features; instead we focus on reducing the expert's labor costs. We first present a new in-depth analysis of potential attacks methodology and then translate the bytecode of solidity into RGB color code. After that, we transform them to a fixed-sized encoded image. Finally, the encoded image is fed to convolutional neural network (CNN) for automatic feature extraction and learning, detecting compiler bugs of Ethereum smart contract.
Ruinian Li, Tianyi Song, Bo Mei, Hong Li · 6 authors
With the dramatically increasing deployment of IoT devices, storing and protecting the large volume of IoT data has become a significant issue. Traditional cloud-based IoT structures impose extremely high computation and storage demands on the cloud servers. Meanwhile, the strong dependencies on the centralized servers bring significant trust issues. To mitigate these problems, we propose a distributed data storage scheme employing blockchain and cetrificateless cryptography. Our scheme eliminates the traditional centralized servers by leveraging the blockchain miners who perform “transaction” verifications and records audit with the help of certificateless cryptography. We present a clear definition of the transactions in a non-cryptocurrency system and illustrate how the transactions are processed. To the best of our knowledge, this is the first work designing a secure and accountable IoT storage system using blockchain. Additionally, we extend our scheme to enable data trading and elaborate how data trading can be efficiently and effectively achieved.
With their innovative and fundamentally liberalising approach to data storage, distributive ledger technologies (DLTs) like blockchain—and other associated technologies offer immense benefits to both the public and private sectors, not least in terms of upping efficiency. Lovers of freedom should also note, however, that they offer an important chance to empower individuals in their necessary engagements with the state, and to rebuild societal trust for the common good. In this paper, we propose the establishment of a UK-based international blockchain competition, and a public-facing **‘Chief Blockchain Officer.’** We also propose a UK **‘blockchain departmental target’**: a long-term aim for government departments to make a 1% efficiency saving by embracing blockchain and other associated innovative technologies. A renewed UK focus on efficiency and the opportunities of new technology would be inspirational, and we look forward to discussing these proposals, and carrying out further research into Distributed Ledger Technologies.
Blockchain is an emerging technology that enables new forms of decentralized software architectures, where distributed components can reach agreements on shared system states without trusting a central integration point. Blockchain provides a shared infrastructure to execute programs, called smart contracts, and to store data. Since blockchain technologies are at an early stage, there is a lack of a systematic and holistic view on designing software systems that use blockchain. We view blockchain as part of a bigger system, which requires patterns for using blockchain in the design of their software architecture. In this paper, we collect a list of patterns for blockchain-based applications. The pattern collection is categorized into four types, including interaction with external world patterns, data management patterns, security patterns and contract structural patterns. Some patterns are designed considering the nature of blockchain and how it can be specifically introduced within real-world applications. Others are variants of existing design patterns applied in the context of blockchain-based applications and smart contracts.
This article evaluates the legal framework of cryptocurrency in various countries. The new currency instrument is abstract currencies. They are currencies in the sense that they can be exchanged peer-to-peer. They are representations of numbers, i.e. abstract objects. An abstract currency system is a self-enforcing system of property rights over an abstract instrument which gives its owners the freedom to use and the right to exclude others from using the instrument. Cryptocurrency or virtual currency is a cryptographically protected, decentralized digital currency used as a means of exchange. Due to the development of new technologies and innovations, the rate of use of virtual currency is rapidly increasing throughout the globe, replacing not only cash payments and payments by bank transfer, but also electronic cash payments. Among the best-known representatives of cryptocurrencies are Bitcoin, Litecoin and Ethereum. Legal scholars have not yet reached a consensus regarding the nature and legal status of virtual currency. Virtual currency possesses the nature of obligations righ ts as well as property rights, since it may be both a means of payment and a commodity. Depending on the country, the approach to cryptocurrencies may be different. Today there is already an international cryptocurrency community that does not have a single coordinating center. Only progressive jurisdiction and state regulation of cryptocurrency activity will allow the creation of the conditions that will ensure the implementation of legitimate and safe cryptocurrency relations.
Maged N. Kamel Boulos, James T. Wilson, Kevin A. Clauson
A PubMed query run in June 2018 using the keyword 'blockchain' retrieved 40 indexed papers, a reflection of the growing interest in blockchain among the medical and healthcare research and practice communities. Blockchain's foundations of decentralisation, cryptographic security and immutability make it a strong contender in reshaping the healthcare landscape worldwide. Blockchain solutions are currently being explored for: (1) securing patient and provider identities; (2) managing pharmaceutical and medical device supply chains; (3) clinical research and data monetisation; (4) medical fraud detection; (5) public health surveillance; (6) enabling truly public and open geo-tagged data; (7) powering many Internet of Things-connected autonomous devices, wearables, drones and vehicles, via the distributed peer-to-peer apps they run, to deliver the full vision of smart healthy cities and regions; and (8) blockchain-enabled augmented reality in crisis mapping and recovery scenarios, including mechanisms for validating, crediting and rewarding crowdsourced geo-tagged data, among other emerging use cases. Geospatially-enabled blockchain solutions exist today that use a crypto-spatial coordinate system to add an immutable spatial context that regular blockchains lack. These geospatial blockchains do not just record an entry's specific time, but also require and validate its associated proof of location, allowing accurate spatiotemporal mapping of physical world events. Blockchain and distributed ledger technology face similar challenges as any other technology threatening to disintermediate legacy processes and commercial interests, namely the challenges of blockchain interoperability, security and privacy, as well as the need to find suitable and sustainable business models of implementation. Nevertheless, we expect blockchain technologies to get increasingly powerful and robust, as they become coupled with artificial intelligence (AI) in various real-word healthcare solutions involving AI-mediated data exchange on blockchains.
Decentralized Ledger Technology, popularized by the Bitcoin network, aims to keep track of a ledger of valid transactions between agents of a virtual economy without a central institution for coordination. In order to keep track of a faithful and accurate list of transactions, the ledger is broadcast and replicated across machines in a peer-to-peer network. To enforce validity of transactions in the ledger (i.e., no negative balance or double spending), the network as a whole coordinates to accept or reject new transactions based on a set of rules aiming to detect and block operations of malicious agents (i.e., Byzantine attacks). Consensus protocols are particularly important to coordinate operation of the network, since they are used to reconcile potentially conflicting versions of the ledger. Regardless of architecture and consensus mechanism used, resulting economic networks remain largely similar, with economic agents driven by incentives under a set of rules. Due to the intense activity in this area, proper mathematical frameworks to model and analyze behavior of blockchain-enabled systems are essential. In this paper, we address this need and provide the following contributions: (i) we establish a formal framework, with tools from dynamical systems theory, to mathematically describe core concepts in blockchain-enabled networks, (ii) we apply this framework to the Bitcoin network and recover its key properties, and (iii) we connect our modeling framework with powerful tools from control engineering, such as Lyapunov-like functions, to properly engineer economic systems with provable properties. Apart from the aforementioned contributions, the mathematical framework herein proposed lays a foundation for engineering more general economic systems built on emerging Turing complete networks, such as the Ethereum network, through which complex alternative economic models are explored.
Nowadays, many home appliances use electricity to operate. However, prediction of the electricity usage is not easy and accurate. A prepayment scheme provides the better way to forecast domestic electricity usage. Traditionally, the prepayment scheme is based on the centralized server or the standalone embedded machine, but the centralized service is highly vulnerable to security threats and potential attacks. The purpose of this paper is to describe our design of a peer-to-peer token bill system for the domestic electricity distribution. It also describes the trusted information transaction among the Internet-of-Things devices. In addition, we provide a conceptual overview of the blockchain-based Wattcoin payment system. In this system, a wallet is created by using the cryptography technique that generates private key, public key and the wallet address. Then, the transaction is done when the digital signature is used to authenticate every transaction floating in the network. Moreover, this paper illustrates blockchain message protocol for message exchange among devices.
Ethereum platforma za pametne ugovore svjetlo dana je ugledala 2015. godine, a bila je predložena već 2013. godine. Ona je uvelike inspirirana prvom i najpoznatijom kriptovalutom Bitcoin. Mi smo upotrijebili Ethereum platformu da napravimo pametni ugovor u programskom jeziku Solidity. Svrha tog pametnog ugovora je prediktivno definiranje budućih događaja. Nad tim pametnim ugovorim izgradili smo odgovarajuću web aplikaciju. Pri implementaciji naišli smo na određene tehničke probleme i probleme u vezi sinkronizacije. Takvi problemi su uobičajeni u većini distribuiranih aplikacija. U ovome diplomskom radu smo adresirali i raspravili te konkretne probleme.