The public key infrastructure-based authentication protocol provides basic security services for the vehicular ad hoc networks (VANETs). However, trust and privacy are still open issues due to the unique characteristics of VANETs. It is crucial to prevent internal vehicles from broadcasting forged messages while simultaneously preserving the privacy of vehicles against the tracking attacks. In this paper, we propose a blockchain-based anonymous reputation system (BARS) to establish a privacy-preserving trust model for VANETs. The certificate and revocation transparency is implemented efficiently with the proofs of presence and absence based on the extended blockchain technology. The public keys are used as pseudonyms in communications without any information about real identities for conditional anonymity. In order to prevent the distribution of forged messages, a reputation evaluation algorithm is presented relying on both direct historical interactions and indirect opinions about vehicles. A set of experiments is conducted to evaluate BARS in terms of security, validity, and performance, and the results show that BARS is able to establish a trust model with transparency, conditional anonymity, efficiency, and robustness for VANETs.
Electronic Health Records (EHRs) are entirely controlled by hospitals instead of patients, which complicates seeking medical advices from different hospitals. Patients face a critical need to focus on the details of their own healthcare and restore management of their own medical data. The rapid development of blockchain technology promotes population healthcare, including medical records as well as patient-related data. This technology provides patients with comprehensive, immutable records, and access to EHRs free from service providers and treatment websites. In this paper, to guarantee the validity of EHRs encapsulated in blockchain, we present an attribute-based signature scheme with multiple authorities, in which a patient endorses a message according to the attribute while disclosing no information other than the evidence that he has attested to it. Furthermore, there are multiple authorities without a trusted single or central one to generate and distribute public/private keys of the patient, which avoids the escrow problem and conforms to the mode of distributed data storage in the blockchain. By sharing the secret pseudorandom function seeds among authorities, this protocol resists collusion attack out of N from N -1 corrupted authorities. Under the assumption of the computational bilinear Diffie-Hellman, we also formally demonstrate that, in terms of the unforgeability and perfect privacy of the attribute-signer, this attribute-based signature scheme is secure in the random oracle model. The comparison shows the efficiency and properties between the proposed method and methods proposed in other studies.
Blockchain (BC), the technology behind the Bitcoin crypto-currency system, is considered to be both alluring and critical for ensuring enhanced security and (in some implementations, non-traceable) privacy for diverse applications in many other domains - including in the Internet of Things (IoT) eco-system. Intensive research is currently being conducted in both academia and industry applying the Blockchain technology in multifarious applications. Proof-of-Work (PoW), a cryptographic puzzle, plays a vital rôle in ensuring BC security by maintaining a digital ledger of transactions, which is considered to be incorruptible. Furthermore, BC uses a changeable Public Key (PK) to record the users’ identity, which provides an extra layer of privacy. Not only in cryptocurrency has the successful adoption of BC been implemented but also in multifaceted non-monetary systems such as in: distributed storage systems, proof-of-location, healthcare, decentralized voting and so forth. Recent research articles and projects/applications were surveyed to assess the implementation of BC for enhanced security, to identify associated challenges and to propose solutions for BC enabled enhanced security systems.
In traditional cloud storage systems, attribute-based encryption (ABE) is regarded as an important technology for solving the problem of data privacy and fine-grained access control. However, in all ABE schemes, the private key generator has the ability to decrypt all data stored in the cloud server, which may bring serious problems such as key abuse and privacy data leakage. Meanwhile, the traditional cloud storage model runs in a centralized storage manner, so single point of failure may leads to the collapse of system. With the development of blockchain technology, decentralized storage mode has entered the public view. The decentralized storage approach can solve the problem of single point of failure in traditional cloud storage systems and enjoy a number of advantages over centralized storage, such as low price and high throughput. In this paper, we study the data storage and sharing scheme for decentralized storage systems and propose a framework that combines the decentralized storage system interplanetary file system, the Ethereum blockchain, and ABE technology. In this framework, the data owner has the ability to distribute secret key for data users and encrypt shared data by specifying access policy, and the scheme achieves fine-grained access control over data. At the same time, based on smart contract on the Ethereum blockchain, the keyword search function on the cipher text of the decentralized storage systems is implemented, which solves the problem that the cloud server may not return all of the results searched or return wrong results in the traditional cloud storage systems. Finally, we simulated the scheme in the Linux system and the Ethereum official test network Rinkeby, and the experimental results show that our scheme is feasible.
The Blockchain technology can be defined as a distributed ledger database for recording transactions between parties verifiably and permanently. Blockchain emerged as a leading technology layer for financial applications. Nevertheless, in the past years, the attention of researchers and practitioners moved to the application of the Blockchain technologies to other domains. Recently, it represents the backbone of a new digital supply chain. Thanks to its capability of ensuring data immutability and public accessibility of data streams, Blockchain can increase the efficiency, reliability, and transparency of the overall supply chain, and optimize the inbound processes. The literature concerning Blockchain in non-financial applications mainly focused on the technological part and the Business Process Modeling, lacking in terms of standard methodology for designing a strategy to develop and validate the overall Blockchain solution and integrate it in the Business Strategy. Thus, this paper aims to overcome this lack. First, we integrate the current literature filling the lack concerning the digital strategy, creating a standard methodology to design Blockchain technology use cases, which are not related to finance applications. Second, we present the results of a use case in the fresh food delivery, showing the critical aspects of implementing a Blockchain solution. Moreover, the paper discusses how the Blockchain will help in reducing the logistics costs and in optimizing the operations and the research challenges.
Blockchain is gaining traction and can be termed as one of the furthermost prevalent topics nowadays. Although critics question about its scalability, security, and sustainability, it has already transformed many individuals' lifestyle in some areas due to its inordinate influence on industries and businesses. Granting that the features of blockchain technology guarantee more reliable and expedient services, it is important to consider the security and privacy issues and challenges behind the innovative technology. The spectrum of blockchain applications range from financial, healthcare, automobile, risk management, Internet of things (IoT) to public and social services. Several studies focus on utilizing the blockchain data structure in various applications. However, a comprehensive survey on technical and applications perspective has not yet been accomplished. In this paper, we try to conduct a comprehensive survey on the blockchain technology by discussing its structure to different consensus algorithms as well as the challenges and opportunities from the prospective of security and privacy of data in blockchains. Furthermore, we delve into future trends the blockchain technology can adapt in the years to come.Index Terms- Blockchains, Future Trends of Blockchains, Security, Privacy
With the help of the Internet of Things (IoT), an evolving technology, issues may be solved in the fields of research and engineering without the involvement of a human workforce. It allows for the creation of interactions between machines and people, or smart work force. Although there may be advantages to integrating blockchain technology with IoT, doing so also creates additional difficulties, such as scalability issues when designing blockchains for IoT applications. In this chapter, we examine the main advantages, design considerations, and possible blockchain applications for the Internet of Things (IoT). A central server model is dropped and blockchain (BC) technology is added as a component of IoT to solve such security and privacy problems. This study examines how the distributed ledger-based blockchain technology affects potential security and privacy concerns related to the interplay of IoT components. Applications of BC with regard to the targeted industries and categories were obviously examined here. To comprehend the role of blockchain technology, certain issues unique to IoT and IoT with BC were also explored.
Conceptually, the blockchain is a distributed database containing records of transactions that are shared among participating members. Each transaction is confirmed by the consensus of a majority of the members, making fraudulent transactions unable to pass collective confirmation. Once a record is created and accepted by the blockchain, it can never be altered or disappear. Nowadays the blockchain technology is considered as the most significant invention after the Internet. If the latter connects people to realize on-line business processes, the former could decide the trust problem by peer-to-peer networking and public-key cryptography. The purpose of this paper is to consider on distinct use cases at the all-pervasive impact of the blockchain technology and look at this as an inalienable part of our daily life.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Weizhi Meng, Elmar Tischhauser, Qingju Wang, Yu Wang · 5 authors
With the purpose of identifying cyber threats and possible incidents, intrusion detection systems (IDSs) are widely deployed in various computer networks. In order to enhance the detection capability of a single IDS, collaborative intrusion detection networks (or collaborative IDSs) have been developed, which allow IDS nodes to exchange data with each other. However, data and trust management still remain two challenges for current detection architectures, which may degrade the effectiveness of such detection systems. In recent years, blockchain technology has shown its adaptability in many fields, such as supply chain management, international payment, interbanking, and so on. As blockchain can protect the integrity of data storage and ensure process transparency, it has a potential to be applied to intrusion detection domain. Motivated by this, this paper provides a review regarding the intersection of IDSs and blockchains. In particular, we introduce the background of intrusion detection and blockchain, discuss the applicability of blockchain to intrusion detection, and identify open challenges in this direction.
Wei Cai, Zehua Wang, Jason B. Ernst, Zhen Hong · 6 authors
Blockchain technology has attracted tremendous attention in both academia and capital market. However, overwhelming speculations on thousands of available cryptocurrencies and numerous initial coin offering (ICO) scams have also brought notorious debates on this emerging technology. This paper traces the development of blockchain systems to reveal the importance of decentralized applications (dApps) and the future value of blockchain. We survey the state-of-the-art dApps and discuss the direction of blockchain development to fulfill the desirable characteristics of dApps. The readers will gain an overview of dApp research and get familiar with recent developments in the blockchain.
Hubert Pun, Jayashankar M. Swaminathan, Pengwen Hou
Counterfeiting is a severe problem in many sectors. There are two types of counterfeits: non‐deceptive and deceptive. While both types are important business challenge, deceptive counterfeit has an additional negative impact—customers have a post‐purchase regret if they expect to purchase a real product but ended up with a fake. The focus of this study is on the setting that relates to deceptive counterfeits. Our paper is one of the first that examines the effectiveness of blockchain as a solution to a supply chain challenge. Specifically, the unique feature of blockchain that we model, which none of the traditional strategies studied in the literature is capable of, is that blockchain adoption changes the analysis from a deceptive counterfeit setting to a non‐deceptive counterfeit setting. We also consider government being a decision maker and customers' privacy concern from blockchain adoption, two features that are not examined in the existing literature. We consider a market with a manufacturer and a deceptive counterfeiter. The manufacturer can signal product authenticity either with blockchain technology or through pricing. The government can provide subsidy to encourage blockchain adoption. Blockchain should be used when the counterfeit quality is intermediate or when customers have intermediate distrust about products in the market. If government provides subsidy, blockchain can be more effective than differential pricing strategy in eliminating post‐purchase regret. Our results advocate for government providing subsidy because it benefits both customers and the society and could be a better approach than government enforcement efforts.
Purpose This paper aims to strive to close the current research gap pertaining to potential implications of the blockchain for supply chain management (SCM) by presenting a framework built on four established economic theories, namely, principal agent theory (PAT), transaction cost analysis (TCA), resource-based view (RBV) and network theory (NT). These theories can be used to derive research questions that are theory-based as well as relevant for the industry. This paper is intended to initiate and stimulate an academic discussion on the potential impact of the blockchain and introduces a framework for middle-range theorizing together with several research questions. Design/methodology/approach This paper builds on previous theories that are frequently used in SCM research and shows how they can be adapted to blockchain-related questions. Findings This paper introduces a framework for middle-range theorizing together with several research questions. Research limitations/implications The paper presents blockchain-related research questions derived from four frequently used theories, namely, PAT, TCA, RBV and (NT). These questions will guide future research pertaining to structural (PAT, TCA) and managerial issues (RBV, NT) and will foster middle-range theory development in SCM research. Practical implications Blockchain technology has the potential to significantly change SCM. Given the huge investments by industry, academic research is needed which investigates potential implications and supports companies. In this paper, various research questions are introduced that illustrate how the implications of blockchain on SCM can be investigated from different perspectives. Originality/value To the best of the author’s knowledge, no academic papers are published in leading academic journals that investigate the relationship between SCM and blockchain from a theory-based perspective.
Peng Zhang, Jules White, Douglas C. Schmidt, Gunther Lenz · 5 authors
Secure and scalable data sharing is essential for collaborative clinical decision making. Conventional clinical data efforts are often siloed, however, which creates barriers to efficient information exchange and impedes effective treatment decision made for patients. This paper provides four contributions to the study of applying blockchain technology to clinical data sharing in the context of technical requirements defined in the “Shared Nationwide Interoperability Roadmap” from the Office of the National Coordinator for Health Information Technology (ONC). First, we analyze the ONC requirements and their implications for blockchain-based systems. Second, we present FHIRChain, which is a blockchain-based architecture designed to meet ONC requirements by encapsulating the HL7 Fast Healthcare Interoperability Resources (FHIR) standard for shared clinical data. Third, we demonstrate a FHIRChain-based decentralized app using digital health identities to authenticate participants in a case study of collaborative decision making for remote cancer care. Fourth, we highlight key lessons learned from our case study.
Interoperability in healthcare has traditionally been focused around data exchange between business entities, for example, different hospital systems. However, there has been a recent push towards patient-driven interoperability, in which health data exchange is patient-mediated and patient-driven. Patient-centered interoperability, however, brings with it new challenges and requirements around security and privacy, technology, incentives, and governance that must be addressed for this type of data sharing to succeed at scale. In this paper, we look at how blockchain technology might facilitate this transition through five mechanisms: (1) digital access rules, (2) data aggregation, (3) data liquidity, (4) patient identity, and (5) data immutability. We then look at barriers to blockchain-enabled patient-driven interoperability, specifically clinical data transaction volume, privacy and security, patient engagement, and incentives. We conclude by noting that while patient-driving interoperability is an exciting trend in healthcare, given these challenges, it remains to be seen whether blockchain can facilitate the transition from institution-centric to patient-centric data sharing.
Roman Beck, Christoph Müller-Bloch, John Leslie King
Blockchain technology is often referred to as a groundbreaking innovation and the harbinger of a new economic era. Blockchains may be capable of engendering a new type of economic system: the blockchain economy. In the blockchain economy, agreed-upon transactions would be enforced autonomously, following rules defined by smart contracts. The blockchain economy would manifest itself in a new form of organizational design—decentralized autonomous organizations (DAO)—which are organizations with governance rules specified in the blockchain. We discuss the blockchain economy along dimensions defined in the IT governance literature: decision rights, accountability, and incentives. Our case study of a DAO illustrates that governance in the blockchain economy may depart radically from established notions of governance. Using the three governance dimensions, we propose a novel IT governance framework and a research agenda for governance in the blockchain economy. We challenge common assumptions in the blockchain discourse, and propose promising information systems research related to these assumptions.
The paradigm of Internet of Things (IoT) is paving the way for a world, where many of our daily objects will be interconnected and will interact with their environment in order to collect information and automate certain tasks. Such a vision requires, among other things, seamless authentication, data privacy, security, robustness against attacks, easy deployment, and self-maintenance. Such features can be brought by blockchain, a technology born with a cryptocurrency called Bitcoin. In this paper, a thorough review on how to adapt blockchain to the specific needs of IoT in order to develop Blockchain-based IoT (BIoT) applications is presented. After describing the basics of blockchain, the most relevant BIoT applications are described with the objective of emphasizing how blockchain can impact traditional cloud-centered IoT applications. Then, the current challenges and possible optimizations are detailed regarding many aspects that affect the design, development, and deployment of a BIoT application. Finally, some recommendations are enumerated with the aim of guiding future BIoT researchers and developers on some of the issues that will have to be tackled before deploying the next generation of BIoT applications.
Juliandson Estanislau Ferreira, Filipe Gutemberg Costa Pinto, Simone C. dos Santos
Blockchain é uma tecnologia de gerenciamento de dados cujo funcionamento consiste em transações descentralizadas, sendo desenvolvida para a criptomoeda Bitcoin no contexto de pagamento digital. O interesse na tecnologia blockchain tem aumentado desde que a ideia foi cunhada em 2008. As razões para o interesse na tecnologia blockchain são seus atributos centrais que fornecem segurança, anonimato e integridade de dados sem qualquer interferência de terceiros no controle das transações. Até agora, o blockchain tem atraído bastante atenção da indústria de serviços financeiros, mas a tecnologia pode ser adaptada para qualquer indústria onde seja necessário registrar, confirmar e transferir qualquer tipo de contrato ou propriedade. Nesta pesquisa, realizamos um mapeamento sistemático para estudar como essa tecnologia tem sido utilizada pelas corporações. O objetivo é compreender os principais recursos do blockchain , as novas aplicações que surgiram, impactos, vantagens e desafios. Foram extraídos 21 artigos primários de bases de dados científicas. Os resultados mostram potencial disruptivo da tecnologia, como ela vai mudar a nossa economia e como ela foi adaptada para muitas indústrias. DOI: http://dx.doi.org/10.21714/1679-18272017v15Ed.p108-117
During one of my recent classes, an interesting question, never heard before, was posed by one of the students: "How come that the relativistic acceleration transformation transforms zero acceleration into zero acceleration but transforms zero force into non-zero force?" In the current note I will explain this apparent paradox. The proof is not trivial and, to my best knowledge, cannot be found in the literature. The note is intended for undergraduate students and for instructors who teach special relativity, especially the dynamics chapters. PACS: 03.30.+p
As in 2009 the first encrypted electronic currency Bitcoin is introduced, the block chain technology has received attention. Bitcoin is a currency issued without a trusted third party, in peer-to-peer (Peer-to-Peer) network and gives a guarantee of the reliability of money transactions, ensures the integrity of transactions. There is a back end-technique called block-chain that guarantees these without trusted third party. Block chain is a public ledger that all nodes to verify transactions and maintain integrity with the same ledger. Block chain technology applies not only electronic currency but also in various industries such as contract document integrity, cloud storage service, internet of thigns, supply chain for transaction integrity. However, there are problems to be solved if the bitcoin block chain consensus rule is applied to these industry. First, there is problem of low transaction throughput and block generation rate by an inefficient consensus rule. Second, There is problem of tampered block broadcast with non-dependency (internet of things data, food history data) transactions when applying the block chain consensus rule, which is proof-of-work of bitcoin's competitive system.
Novianti Valentin Ruung, Ventje Ilat, Heince R. N. Wokas
The Indonesian government imposed a policy of regional autonomy with the aim to facilitate local governments regulate local affairs indenpently. Manado city is one of the areas that implement decentralization policy and requires a lot of funds to finance regional development. The biggest potential possessed Manado city in the financingof regional expenditures derived from local taxes and are expected to ptovide the largest contribution in PAD. This study aims to determain the amount of contribions hotel tax and groundwater tax and to analyze hotel tax and groundwater tax the city of Manado. Methods of data analysis in this research is descriptive analysis. Based on the analysis the average contrition colletion hotel and groundwater tax city parking tax is lack and for hotel tax and groundwater tax reporting mechanism are alredy well underway.Keywords : contribution, reporting, hotel tax, groundwater tax
Open access
Economic Growth and Fiscal Policies
Community-based Tourism Development and Sustainability
Financing local communities relies on a complex network of taxes, subsidies and loans. In the last decade the network has undergone numerous transformations .The reforms implanted in past years changed the systems of public finance substantially. Therefore, financial local autonomy is a term that frequently employed in the literature of federalism and decentralization, but it’s rarely defined conceptually in a careful way to empirical research. Generally it expresses the capacity of local communities to have their own revenue and expenditure budget, distinct from that of the state in which revenue can cover expenses incurred to meet their requirements. Indeed it is a highly valued feature of good governance. This paper is dedicated to a study in theory and practice. Starting with an overview on background of theoretical approach of local financial autonomy, then comparing the experiences of two European countries France, Italy and Morocco in the field. The purpose of this paper is to clarify the meaning of local financial autonomy and give a structured overview of the factors that may potentially influence the liberty of sub national authorities with regard of their own revenue and expenditure budget. Based on indicators and taking into account empirical evidences offered by official statistical datas, established in recent years for evaluating the position of administrative territorial units in relation to central government. The analyses prove that there is no universal model of local public finance applicable to all countries, because each has its own specific historical, cultural and linguistic particularities.
Saghrane Mohamed Yassine, Alaoui Lalla Latifa, Benayache Sarah
Bitcoin is a technology operating without a central authority. The management of the transaction and the creation of bitcoins constitute an assumption of responsibility collectively by the network. Bitcoin is free and open. Its design is public, nobody has nor controls this type of currency and any individual can purchase it. Thanks to several of its single properties, Bitcoin entails promising uses, which are not presently covered by the systems of classic payments. The digital currency bitcoin primarily relies on a type of technology referred to as blockchain and has several implications for the economy and corporations. Bitcoins are used everywhere in the world and can serve as a tool of decentralization and freedom. There is a significant number of companies and individuals who use Bitcoin, with certain organizations currently accepting it as a method of payment. Although Bitcoin remains a relatively new phenomenon, it has experienced a rapid growth. At the end of August 2017, the value of all the bitcoins in circulation exceeded 16.5 million bitcoin with millions of dollars exchanged daily in bitcoins (market cap 77 billion dollar). This paper will provide a brief outline of this subject, along with essential information on Blockchain and bitcoin. After providing a definition of the latter two, we will present their impact on the financial industry, and finally we will evaluate the function of the stock of value on the calculation of the volatility of the bitcoin by reporting it to gold and the EUR/USD parity.
ÄlĂĄnek pomocĂ simulace provedenĂŠ v programu Minsky zkoumĂĄ efekty pĹeddefinovanĂŠ a nemÄnnĂŠ monetĂĄrnĂ politiky podle vzoru fungovĂĄnĂ kryptomÄny Bitcoin a porovnĂĄvĂĄ je s vĂ˝sledky souÄasnĂŠho mÄnovĂŠho systĂŠmu kreditnĂ fiat mÄny. Minsky je specializovanĂ˝ software pro tvorbu SFC ekonomickĂ˝ch modelĹŻ. Pracuje ve spojitĂŠm Äase. Bitcoin je na rozdĂl od eura aktivnĂ mÄna, kterĂĄ nenĂ vytvĂĄĹenĂĄ ĂşÄetnÄ proti dluhu a neumoĹžĹuje fiduciĂĄrnĂ emisi. Studie zkoumĂĄ komplexnÄ ekonomiku EU se zamÄĹenĂm na jejĂ mÄnovĂ˝ systĂŠm, a to za pouĹžitĂ dat poskytovanĂ˝ch Eurostatem. NĂĄslednÄ mÄnĂ pravidla systĂŠmu tak, aby odpovĂdala pravidlĹŻm protokolu Bitcoinu. ProvedenĂŠ simulace ukazujĂ po Äase odliĹĄnĂŠ dopady tÄchto systĂŠmovĂ˝ch nastavenĂ na rozdÄlenĂ bohatstvĂ mezi jednotlivĂŠ skupiny ekonomickĂ˝ch agentĹŻ a na stabilitu ekonomiky jako celku.