Blockchain technology is ushering in another break-out year, the challenge of blockchain still remains to be solved. This paper analyzes the features of Bitcoin and Bitcoin-NG system based on blockchain, proposes an improved method of implementing blockchain systems by replacing the structure of the original chain with the graph data structure. It was named GraphChain. Each block represents a transaction and contains the balance status of the traders. Additionally, as everyone knows all the transactions in Bitcoin system will be baled by only one miner that will result in a lot of wasted effort, so another way to improve resource utilization is to change the original way to compete for miner to election and parallel mining. Researchers simulated blockchain with graph structure and parallel mining through python, and suggested the conceptual new graph model which can improve both capacity and performance.
Aug 1, 2018·2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
Many Internet services require the registration of an account before permitting use of their services. Over time, many Internet users end up with a multitude of accounts with separated identities. A solution to this problem is offered by single-sign-on (SSO) providers, where a user can create a single identity and use this identity for multiple services. However it requires the user to trust the SSO provider. When the provider blocks access to the identities the users lose access to their subscribed services. To avoid this problem, we propose DecentID, a completely decentralized identity storage system that does not require a centralized trusted third party. Instead, a public blockchain is used as trust anchor. Identities can be created and used for different services. Each service can only read the identity attributes disclosed for it without being able to read attributes the user wants to keep secret.
Νικόλαος Αλεξόπουλος, Sheikh Mahbub Habib, Max Mühlhäuser
Authorization, and more generally Trust Management (TM), is an indispensable part of the correct operation of most IT systems. The advent of the Internet of Things (IoT), with its cyber-physical and distributed nature, creates new challenges, that existing TM systems cannot adequately address, such as for example the need for non-interactive exclusive access enforcement. In the meantime, a line of thought in the research community is that Distributed Ledgers (DLs), like the one implemented by the Ethereum blockchain, can provide strong security guarantees for distributed access control. However, this approach has not yet been examined in a scientific, systematic manner, and has many pitfalls, with arguably the most important one being scalability.
Peer-to-Peer (P2P) networking is a decentralized network topology that enables parties to communicate directly without central servers. The main obstacle preventing the heavy deployment of the P2P topology is the Network Address Translation (NAT) which serves as a solution for the exhaustion of IPv4 addresses. Methods proposed by the Internet Engineering Task Force (IETF) to solve the NAT traversal issues include Simple Traversal of UDP through NATs (STUN) and Traversal Using Relay NAT (TURN). STUN is limited by the type of deployed NAT, and TURN is limited by the peers' discovery mechanism which is application dependent. In this paper we propose a Blockchain-based platform that enables TURN servers to act as relays for Internet of Things (IoT) devices behind NAT. It also provides End-to-End (e2e) security for Constrained and Non-Constrained IoT devices. Results showed that the system has minimal impact on the existing network and can be a potential solution for advancing IoT deployment.
Aug 1, 2018·2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
Blockchain technology though originally designed for keeping financial ledgers, recently has found applications in many different fields including healthcare. Sharing healthcare data for research purposes will boost research innovation in this area. That being said, healthcare data sharing raises many privacy and security issues for the Patients who share their data. In this work, we present the potential of Blockchain technology to facilitate (i) private and auditable healthcare data sharing and (ii) healthcare data access permission handling by proposing a blockchain-based system architecture design.
Blockchain has proved itself to be tamper resistant and secure. It is increasingly getting attention from companies changing from centralized to decentralized systems. This paper proposes a system for identity and access management using blockchain technology to support authentication and authorization of entities in a digital system. A prototype demonstrates the application of blockchain in identity and access management using the Hyperledger Fabric framework. It provides a proof of concept based on a use case concerning Electronic Health Records from the healthcare domain where an immutable and auditable history is desired for data concerning patients. Basic authentication and authorization operations are able to execute in 2-3 seconds with an initial size of blockchain of about 3.8 MB covering physicians in Denmark.
Virtual currencies are on the rise and so is money laundering. While there are efforts to combat money laundering through various intergovernmental bodies, many have expressed concern over the rise of virtual currencies. Some cryptocurrencies such as Bitcoin have played a major role in the proliferation of online money laundering as it possesses characteristics that criminals are fond of. Bitcoin and other cryptocurrencies are decentralised, anonymous/pseudonymous and irreversible. They provide the means to skirt the Anti-Money laundering safeguards that have been put in place. \nThis paper discusses the intersection between Anti-Money Laundering efforts and the challenges that are introduced by cryptocurrencies such as Bitcoin. It also looks at the case of Liberty Reserve to highlight these challenges.
Muniba Memon, Syed Shahbaz Hussain, Umair Ahmed Bajwa, Asad Ikhlas
In the world of Internet of Things, social media, and cloud computing, blockchain is the latest addition to the technology. The swift development of blockchain and its respected applications has made it a force to be recognized. But the scope of blockchain is not limited to bitcoin or the cryptocurrencies implementation. This paper enlightens the stipulation of blockchain beyond the bitcoin. Furthermore, this paper reveals the insights of blockchain technology concepts, evolution, mechanisms and challenges based on literature review. This paper identified the complications or challenges in implementation of blockchain technology in real-world applications. Secure implementation of blockchain technology on small scale applications is the key problem that still need to be addressed. The proposed consensus mechanism would be useful for secure implementation of the blockchain on small-scale application or projects.
In blockchain systems, especially cryptographic currencies such as Bitcoin, the double-spending and Byzantine-general-like problem are solved by reaching consensus protocols among all nodes. The state-of-the-art protocols include Proof-of-Work, Proof-of-Stake and Delegated-Proof-of-Stake. Proof-of-Work urges nodes to prove their computing power measured in hash rate in a crypto-puzzle solving competition. The other two take into account the amount of stake of each nodes and even design a vote in Delegated-Proof-of-Stake. However, these frameworks have several drawbacks, such as consuming a large number of electricity, leading the whole blockchain to a centralized system and so on. In this paper, we propose the conceptual framework, fundamental theory and research methodology, based on artificial intelligence technology that exploits nearly complementary information of each nodes. And we designed a particular convolutional neural network and a dynamic threshold, which obtained the super nodes and the random nodes, to reach the consensus. Experimental results demonstrate that our framework combines the advantages of Proof-of-Work, Proof-of-Stake and Delegated-Proof-of-Stake by avoiding complicated hash operation and monopoly. Furthermore, it compares favorably to the three state-of-the-art consensus frameworks, in terms of security and the speed of transaction confirmation.
At present, medical images account for nearly 70% of medical diagnostic data, which is an important basis for disease diagnosis. However, medical data leakage incidents have occurred in more than 90% medical institutions, the protection of patients' medical data is of great urgency. At present, all types of medical institutions involved in the medical imaging business use the PACS to archive, manage, and use the collected medical images, but only sharing the managed video resources within the organization. This method applies only the traditional data protection strategy and cannot guarantee a stronger protection for patients' private information. And patients have no control over medical information at the time of treatment. For this reason, this paper proposes a method of secure sharing of medical images based on smart contracts of block chain and credit scores. Through a blockchain based on distributed, reliable database of recording image sharing process, we realize a cross-organizational, cross-regional, trustworthy, and supervisory medical image sharing system. And the establishment of smart contracts based on credit scores of patients and medical institutions guarantee intelligent sharing by rules and conditions. Compared with traditional PACS, the method proposed in this paper extends its scope of application on the basis of PACS, increases its robustness, and provides new ideas for more extensive, multi-level, safe and reliable medical images sharing.
Artificial Intelligence in Healthcare and Education
Bitcoin is the first implementation of a technology that has become known as a 'public permissionless' blockchain. Such systems allow public read/write access to an append-only blockchain database without the need for any mediating central authority. Instead, they guarantee access, security and protocol conformity through an elegant combination of cryptographic assurances and game theoretic economic incentives. Not until the advent of the Bitcoin blockchain has such a trusted, transparent, comprehensive and granular dataset of digital economic behaviours been available for public network analysis. In this article, by translating the cumbersome binary data structure of the Bitcoin blockchain into a high fidelity graph model, we demonstrate through various analyses the often overlooked social and econometric benefits of employing such a novel open data architecture. Specifically, we show: (i) how repeated patterns of transaction behaviours can be revealed to link user activity across the blockchain; (ii) how newly mined bitcoin can be associated to demonstrate individual accumulations of wealth; (iii) through application of the naïve quantity theory of money that Bitcoin's disinflationary properties can be revealed and measured; and (iv) how the user community can develop coordinated defences against repeated denial of service attacks on the network. Such public analyses of this open data are exemplary benefits unavailable to the closed data models of the 'private permissioned' distributed ledger architectures currently dominating enterprise-level blockchain development owing to existing issues of scalability, confidentiality and governance.
The era of transformation powered by digitization, improvements in information and communication technology, machine learning, robotics and artificial intelligence is upon us. Today, we are able to solve complex problems with the aid of technology. That notwithstanding, animal populations globally are under threat, with the extinction of species taking place at a far accelerated pace than can be reversed, thus making wildlife conservation a critical issue of our time. Along with wildlife extinction currently underway, there remains a chronic financial shortage for wildlife conservation and the funding shortfall is expanding annually. This research contends that blockchain, the technology underpinning cryptocurrencies such as Bitcoin can be utilized as a catalyst by the development of cryptowildlife nonfungible tokens (NFTs), which are provably scarce, unique and programmable digital wildlife collectible assets. These could be used to finance wildlife conservation as a supplementary source of revenue.
The food supply chain is a complex system that involves a multitude of "stakeholders" such as farmers, production factories, distributors, retailers and consumers. "Information asymmetry" between stakeholders is one of the major factors that lead to food fraud. Some current researches have shown that applying blockchain can help ensure food safety. However, they tend to study the traceability of food but not its supervision. This paper provides a blockchain-based credit evaluation system to strengthen the effectiveness of supervision and management in the food supply chain. The system gathers credit evaluation text from traders by smart contracts on the blockchain. Then the gathered text is analyzed directly by a deep learning network named Long Short Term Memory (LSTM). Finally traders' credit results are used as a reference for the supervision and management of regulators. By applying blockchain, traders can be held accountable for their actions in the process of transaction and credit evaluation. Regulators can gather more reliable, authentic and sufficient information about traders. The results of experiments show that adopting LSTM results in better performance than traditional machine learning methods such as Support Vector Machine (SVM) and Navie Bayes (NB) to analyze the credit evaluation text. The system provides a friendly interface for the convenience of users.
Aug 1, 2018·2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
Mohammad Jabed Morshed Chowdhury, Alan Colman, Muhammad Ashad Kabir, Jun Han · 5 authors
In recent times, Bitcoin has gained special attention both from industry and academia. The underlying technology that enables Bitcoin (or more generally crypto-currency) is called blockchain. At the core of the blockchain technology is a data structure that keeps record of the transactions in the network. The special feature that distinguishes it from existing technology is its immutability of the stored records. To achieve immutability, it uses consensus and cryptographic mechanisms. As the data is stored in distributed nodes this technology is also termed as "Distributed Ledger Technology (DLT)". As many researchers and practitioners are joining the hype of blockchain, some of them are raising the question about the fundamental difference between blockchain and traditional database and its real value or potential. In this paper, we present a critical analysis of both technologies based on a survey of the research literature where blockchain solutions are applied to various scenarios. Based on this analysis, we further develop a decision tree diagram that will help both practitioners and researchers to choose the appropriate technology for their use cases. Using our proposed decision tree we evaluate a sample of the existing works to see to what extent the blockchain solutions have been used appropriately in the relevant problem domains.
Advancements in sensors and devices have enabled Internet of Things (IoT) adoption in various sectors, especially in domains looking to automate and increase their real-time decision making capabilities to improve efficiencies. Supply chain management in logistics is a perfect fit for adoption of IoT, since it involves shipment of assets being moved, tracked and housed by a number of machines, vehicles and people each day. Smart Contracts are terms and conditions parties can specify that assure trust in the enforceability of the contract and provide visibility at every step of a supply chain. IoT devices can write to a smart contract as a product moves from the factory floor to the store shelves, providing real-time visibility of an enterprises entire supply chain. This paper proposes a smart logistics solution encapsulating smart contracts, logistics planner and condition monitoring of the assets in the Supply Chain Management area. A prototype of the solution is implemented which demonstrates accountability, traceability and liability for asset handling across the supply chain by various parties involved in a logistics scenario.
Arti Jain, Shashank Tripathi, Harsh Dhar Dwivedi, Pranav Saxena
The problem is to find a method to predict the two-hour price of cryptocurrencies on the basis of the Social Factors, which are increasingly used for online transactions worldwide. The few previous methods proposed to predict price of cryptocurrency are inefficient because they fail to take into consideration the differences in the attributes between real currencies and cryptocurrencies. In this paper, we focus on two cryptocurrencies, namely Bitcoin and Litecoin, each with a large market size and user base, and attempt to predict their future prices using multi-linear regression model.
Aug 1, 2018·2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
While blockchain services hold great promise to improve many different industries, there are significant cybersecurity concerns which must be addressed. In this paper, we investigate security considerations for an Ethereum blockchain hosting a distributed energy management application. We have simulated a microgrid with ten buildings in the northeast U.S., and results of the transaction distribution and electricity utilization are presented. We also present the effects on energy distribution when one or two smart meters have their identities corrupted. We then propose a new approach to digital identity management that would require smart meters to authenticate with the blockchain ledger and mitigate identity-spoofing attacks. Applications of this approach to defense against port scans and DDoS, attacks are also discussed.
Cryptocurrencies like Bitcoin not only provide a decentralized currency, but also provide a programmatic way to process transactions. Ethereum, the second largest cryptocurrency next to Bitcoin, is the first to provide a Turing-complete language to specify transaction processing, thereby enabling so-called smart contracts. This provides an opportune setting for attackers, as security vulnerabilities are tightly intertwined with financial gain. In this paper, we consider the problem of automatic vulnerability identification and exploit generation for smart contracts. We develop a generic definition of vulnerable contracts and use this to build TEE THER, a tool that allows creating an exploit for a contract given only its binary bytecode. We perform a large-scale analysis of all 38,757 unique Ethereum contracts, 815 out of which our tool finds working exploits for—completely automated.
Aug 1, 2018·2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
Andreas Abraham, Kevin Theuermann, Emanuel Kirchengast
Traditional identity management systems (IdMS) suffer from significant weaknesses, such as the reliance on a single central entity that provides the identity data or the users lack control over their identity data. The introduction of qualified self-sovereign identities (SSIs) for eGovernment systems can strengthen the privacy of citizens. Furthermore, it is possible to solve fundamental trust issues of traditional IdMS by utilizing distributed ledger technology (DLT) together with performing a consensus algorithm. The contribution of this paper is twofold. First, this paper proposes a solution for the derivation of qualified electronic identities (eIDs), issued by a traditional IdMS, into a distributed ledger (DL) based IdMS that enables SSIs. Second, we have implemented a proof-of-concept (PoC) realizing qualified eID derivation into an SSI system based on the DLT. This PoC was realized, among others, by introducing an agent that represents the interface between the traditional IdM and the SSI system as well as by extending the consensus algorithm. The proposed approach used for eID derivation ensures the maintenance of the trust as well as the quality of the identity data.
The decentralized nature of existing and future wireless network topologies has opened some unique opportunities for DLT to play a role in communications. In this column, we have reviewed the basic operation of a consensus mechanism, as well as the current trend of a DLT-based security model that is particularly important for loT. We further point out that, beyond application layer and security, DLT also has potential in other aspects of wireless networking such as computing and radio connectivity. Specifically, we see DLT as a perfect tool that should be leveraged to realize fog -RAN, as the consensus mechanism of DLT may be used to maintain tight synchronization among computing and networking resources in different locations. On the other hand, DLT could also be employed to avoid potential collision that may occur in grant -free uplink access. In summary, we believe that DLT will gradually become a key tool to reshape communication systems in a wide range of aspects, covering not just applications and security, but also connectivity and computing.
Bitcoin açık kaynaklı bir kod olarak yayınlanan ve blok zinciri (blockchain) teknolojisine dayanan ilk kriptopara birimidir. Kriptopara birimlerinin avantajı, merkezi olmayan yapılar olması ve bu sayede merkez bankalarına ihtiyaç duymayıp işlem maliyetlerinin az olmasıdır. Bu çalışmanın amacı, son zamanlarda popülerliği artan ve en köklü kriptopara birimi olan Bitcoin getirilerinin kaotik yapıya sahip olup olmadığını tespit etmektir. Başlangıç koşullarına aşırı duyarlı olan seriler kaotik dinamiklere sahiptir. Eğer seriler kaotik özelliklere sahipse, geleneksel yöntemlerle incelenmeleri yanıltıcı sonuçlar verebilmektedir. Bu amaçla, 19.12.2011-29.01.2018 dönemine ait Bitcoin getiri serisi kullanılarak ilk olarak BDS (Brock, Dechert ve Scheinkman) testi ile doğrusal olmayan bağımlılık test edilmiş, ardından serideki uzun dönemli bellek yapısını belirlemek için dönüştürülmüş genişlik (rescaled range-R/S) yöntemi uygulanarak Hurst üsteli elde edilmiştir. Ardından, yanlış en yakın komşular yöntemi ile uygun gömme boyutu belirlenmiştir. Serideki kaotik davranışı tespit etmek için korelasyon boyutu hesaplanmış ve Lyapunov üsteli değeri pozitif bulunmuştur. Sonuç olarak, serinin doğrusal olmayan dinamikler içerdiği, uzun belleğe sahip olduğu ve serinin kaotik özellikler taşıdığı bulgusu elde edilmiştir.
Subhash Ayirala, Ali Al‐Yousef, Zuoli Li, Zhenghe Xu
Summary Smart waterflooding (SWF) through tailoring of injection-water salinity and ionic composition is receiving favorable attention in the industry for both improved and enhanced oil recovery (EOR) in carbonate reservoirs. Surface/intermolecular forces, thin-film dynamics, and capillary/adhesion forces at rock/fluid interfaces govern crude-oil liberation from pores. On the other hand, stability and rigidity of oil/water interfaces control the destabilization of interfacial film to promote coalescence between released oil droplets and to improve the oil-phase connectivity. As a result, the dynamics of oil recovery in smart waterflood is caused by the combined effect of favorable interactions occurring at both oil/brine and oil/brine/rock interfaces across the thin film. Most of the laboratory studies reported so far have been focused on only studying the interactions at rock/fluid interfaces. However, the other important aspect of characterizing water ion interactions at the crude oil/water interface and their impact on film stability and oil-droplet coalescence remains largely unexplored. A detailed experimental investigation was conducted to understand the effects of different water ions at the crude-oil/water interface by using several instruments such as Langmuir trough, interfacial shear rheometer, Attension tensiometer, and coalescence time-measurement apparatus. The reservoir crude oil and four different water recipes with varying salinities and individual ion concentrations were used. Interfacial tension (IFT), interface pressures, compression energy, interfacial viscous and elastic moduli, oil-droplet crumpling ratio, and coalescence time between crude-oil droplets are the major experimental data measured. The IFTs are found to be the largest for deionized (DI) water, followed by the 10-times-reduced-salinity seawater and 10-times-reduced-salinity seawater enriched with sulfates. Interfacial pressures gradually increased with compressing surface area for all the brines and DI water. The compression energy (integration of interfacial pressure over the surface-area change) is the highest for DI water, followed by the lower-salinity brine containing sulfate ions, indicating rigid interfaces. The transition times of interfacial layer to become elastic-dominant from viscous-dominant structures are found to be much shorter for brines enriched with sulfates, once again confirming the rigidity of interface. The crumpling ratios (oil drop wrinkles when contracted) are also higher with the two recipes of DI water and sulfates-only brine to indicate the same trend and to confirm elastic rigid skin at the interface. The coalescence time between oil droplets was the least in brines containing sufficient amounts of magnesium and calcium ions, while the highest in DI water and sulfate-rich brine, respectively. These results, therefore, showed a good correlation of coalescence times with the rigidity of oil/water interface, as interpreted from different measurement techniques. This study, thereby, integrates consistent results obtained from different measurement techniques at the crude-oil/water interface to demonstrate the importance of both salinity and certain ions, such as magnesium and calcium, on crude-oil-droplets coalescence, and to improve oil-phase connectivity in smart waterflood.