The complexity of today's supply chain, organised in several tiers and including many companies located in different countries, makes it challenging to assess the history and integrity of procured physical parts, and to make organisations really accountable for their conduct. This enables malicious practices like counterfeiting and insertion of back doors, which are extremely dangerous, especially in supply chains of physical parts for industrial control systems used in critical infrastructures, where a country and human lives can be put at risk. This paper aims at mitigating these issues by proposing an approach where procured parts are uniquely identified and tracked along the chain, across multiple sites, to detect tampering. Our solution is based on consortium blockchain and smart contract technologies, hence it is decentralised, highly available and provides strong guarantees on the integrity of stored data and executed business logic. The unique identification of parts along the chain is implemented by using physically unclonable functions (PUFs) as tamper-resistant IDs. We first define the threat model of an adversary interested in tampering with physical products along the supply chain, then provide the design of the tracking system that implements the proposed anti-counterfeiting approach. We present a security analysis of the tracking system against the designated threat model and a prototype evaluation to show its technical feasibility and assess its effectiveness in counterfeit mitigation. Finally, we discuss several key practical aspects concerning our solution ad its integration with real supply chains.
Distributed Leger Technologies (DLTs), most notably Blockchain technologies, bring decentralised platforms that eliminate a single trusted third party and avoid the notorious single point of failure vulnerability. Since Nakamoto's Bitcoin cryptocurrency system, an enormous number of decentralised applications have been proposed on top of these technologies, aiming at more transparency and trustworthiness than their traditional counterparts. These applications spread over a lot of areas, e.g. financial services, healthcare, transportation, supply chain management, and cloud computing. While Blockchain brings transparency and decentralised trust intuitively due to the consensus of a (very large) group of nodes (or, miners), it introduces very subtle implications for other desirable properties such as privacy. In this work, we demonstrate these subtle implications for Blockchain-based searchable encryption solutions, which are one specific use case of cloud computing services. These solutions rely on Blockchain to achieve both the standard privacy property and the new fairness property, which requires that search operations are carried out faithfully and are rewarded accordingly. We show that directly replacing the server in an existing searchable encryption solution with a Blockchain will cause undesirable operational cost, privacy loss, and security vulnerabilities. The analysis results indicate that a dedicated server is still needed to achieve the desired privacy guarantee. To this end, we propose two frameworks which can be instantiated based on most existing searchable encryption schemes. Through analysing these two frameworks, we affirmatively show that a carefully engineered Blockchain-based solution can achieve the desired fairness property while preserving the privacy guarantee of the original searchable encryption scheme simultaneously.
Leonardo Aniello, Basel Halak, Peter R. Chai, Riddhi Dhall · 6 authors
The complexity of today's supply chain, organised in several tiers and\nincluding many companies located in different countries, makes it challenging\nto assess the history and integrity of procured physical parts, and to make\norganisations really accountable for their conduct. This enables malicious\npractices like counterfeiting and insertion of back doors, which are extremely\ndangerous, especially in supply chains of physical parts for industrial control\nsystems used in critical infrastructures, where a country and human lives can\nbe put at risk. This paper aims at mitigating these issues by proposing an\napproach where procured parts are uniquely identified and tracked along the\nchain, across multiple sites, to detect tampering. Our solution is based on\nconsortium blockchain and smart contract technologies, hence it is\ndecentralised, highly available and provides strong guarantees on the integrity\nof stored data and executed business logic. The unique identification of parts\nalong the chain is implemented by using physically unclonable functions (PUFs)\nas tamper-resistant IDs. We first define the threat model of an adversary\ninterested in tampering with physical products along the supply chain, then\nprovide the design of the tracking system that implements the proposed\nanti-counterfeiting approach. We present a security analysis of the tracking\nsystem against the designated threat model and a prototype evaluation to show\nits technical feasibility and assess its effectiveness in counterfeit\nmitigation. Finally, we discuss several key practical aspects concerning our\nsolution ad its integration with real supply chains.\n
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Democratic principles demand that every voter should be able to individually verify that their vote is recorded as intended and counted as recorded, without having to trust any authorities. However, most end-to-end (E2E) verifiable voting protocols that provide universal verifiability and voter secrecy implicitly require to trust some authorities or auditors for the correctness guarantees that they provide.
In this paper, we explore the notion of individual verifiability. We evaluate the existing E2E voting protocols and propose a new protocol that guarantees such verifiability without any trust requirements. Our construction depends on a novel vote commitment scheme to capture voter intent that allows voters to obtain a direct zero-knowledge proof of their vote being recorded as intended. We also ensure protection against spurious vote injection or deletion post eligibility verification, and polling-booth level community profiling.
Blockchain for business is a new concept which enables many industries and organizations to implement even the basic of systems on foundation of blockchain technology. Using this technology, our goal is to develop a payments system that enables transfer of funds for a monetary transaction between two parties. Hyperledger is an open source community oriented effort which was made to propel cross-industry blockchain advances that were available. The Linux Foundation has it. It has partners from everywhere throughout the world , at a worldwide dimension and incorporates ventures like funding, banking, Internet of Things, supply chains, assembling and Technology. Using Blockchain for Enterprise technology, we are going to develop a new payments system that makes use of regulated cryptocurrency. Using this system, we want to create a new cryptocurrency specific to the payment portal for people to buy, sell and pay or earn rewards using this cryptocurrency. This system will majorly consist of participants and admins that will be divided based on the certificates assigned to every participant. Our implementation involves. using the fabric for creating a payment system run on the backend of blockchain technology. This will involve having a regulatory authority to maintain the cryptocurrency, ledger and authenticity of the users. Theoretically, the blockchain technology maintains anonymity for transactions. It uses a distributed ledger to record transactions for people to be able to make secure transactions without any repercussions. Blockchain for Enterprise implements Blockchain technology by using concepts like Trust, Privacy and Smart contracts in addition to the distributed ledger to create an industry friendly Blockchain business application. Blockchain is a rapidly growing field with multiple implementations which can be explored not just on anonymity but also on actual life implementations. Distributed ledger technology is applied to the payment systems. Cryptocurrency would now not only be used for anonymous transactions but also for regular day to day transactions.
This paper introduces a new capability for group signatures called message-dependent opening . It is intended to weaken the high trust placed on the opener; i.e., no anonymity against the opener is provided by an ordinary group signature scheme. In a group signature scheme with message-dependent opening (GS-MDO), in addition to the opener, we set up an admitter that is not able to extract any user’s identity but admits the opener to open signatures by specifying messages where signatures on the specified messages will be opened by the opener. The opener cannot extract the signer’s identity from any signature whose corresponding message is not specified by the admitter. This paper presents formal definitions of GS-MDO and proposes a generic construction of it from identity-based encryption and adaptive non-interactive zero-knowledge proofs. Moreover, we propose two specific constructions, one in the standard model and one in the random oracle model. Our scheme in the standard model is an instantiation of our generic construction but the message-dependent opening property is bounded. In contrast, our scheme in the random oracle model is not a direct instantiation of our generic construction but is optimized to increase efficiency and achieves the unbounded message-dependent opening property. Furthermore, we also demonstrate that GS-MDO implies identity-based encryption, thus implying that identity-based encryption is essential for designing GS-MDO schemes.
Samad M. E. Sepasgozar, Reyhaneh Karimi, Sara Shirowzhan, Mohammad Mojtahedi · 6 authors
Delay is one of the main challenges of construction projects, and there is still much to overcome in order to reach near zero delay in all construction projects. This project aims to conduct a systematic critical review including a bibliography analysis on delay literature in construction. The main questions consider what has been learnt from a decade investigating delay causes and effects in the construction literature and what factors have been missed in the literature. This paper also presents a new and challenging question regarding how digital tools and associated technologies may prevent any delay in construction projects, which can change the research direction from delay investigations to identifying prevention factors. The paper identifies the delay dataset, including 493 papers investigating delay in construction, and establishes a specific dataset of papers focusing on delay effects and causes (DEC), including 94 selected papers covering different factors examined in over 29 countries such as Iran, India, Turkey, Bangladesh, Saudi Arabia, the United Arab Emirates (UAE), Cambodia, Oman, Malaysia, Taiwan, China, Vietnam, the US, the UK, and Egypt. In addition, the paper identifies 30 critical factors with the frequency of occurrences over three times in the DEC dataset and computes their medians of ranking. This paper also discusses digital tools and methods that can be used for delay analysis and preventions, including MS Project, Oracle Primavera P6, and Open Plan by Deltek. The paper discusses the project schedule delay analysis from project management methodology perspectives. It also discusses the current method’s limitations and future directions, which are based on the identification of the deficiency areas. In total, four overlooked factors are identified and suggested, including faulty data analysis, unmatched structure of the research questionnaires with new knowledge and standards [e.g., Project Management Body of Knowledge (PMBOK)], overlooked effects of digital technologies [e.g., Digital twin, Navisworks, Building Information Model (BIM), Geographic Information System (GIS), and Integrated Project Delivery (IPD)], and ignored job-site technologies. In addition, the paper presents the DEC model for future studies, including four main key factors. These factors are resources (e.g., project budgets, labour, material, equipment, and digital tool), project context, stakeholders performance (e.g., owner/client, consultant/designer, contractor, vendor/supplier), and external factors (e.g., ground condition, site location, regulation, natural disaster), which may significantly affect delay prevention and should be concurrently considered in the future delay investigations, since they may be required for designing an effective mitigation strategy when these proof points are identified. This would significantly help to utilise digital systems to prevent time overruns in different construction contexts.
With the emergence of distributed ledger technology (DLT), numerous practitioners and researchers have proclaimed its beneficial impact on supply chain transactions in the future. However, the vast majority of DLT initiatives are discontinued after a short period. With the full potential of DLT laying far down the road, especially managers in supply chain management (SCM) seek for short-term cost-saving effects of DLT in order to achieve long-term benefits of DLT in the future. However, the extant research has bypassed grounding long-term as well as short-term effects of DLT on supply chain transaction with empirical data. We address this shortcoming, following an abductive research approach and combining empirical data from a multiple case study design with the corresponding literature. Our study reveals that the effects of DLT on supply chain transactions are two-sided. We found six effects of DLT solutions that have a cost-reducing or cost avoidance impact on supply chain transactions. In addition, we found two effects that change the power distribution between buyers and suppliers in transactions and a single effect that reduces the dependency of supply chain transactions on third parties. While cost-reducing and avoidance as well as dependency-reducing effects are positive effects, the change in power distribution might come with disadvantages. With these findings, the paper provides the first empirical evidence of the impact of DLT on supply chain transactions, which will enable managers to improve their assessment of DLT usage in supply chains.
With the advent of blockchain technology, multiple research avenues and platforms for dialogue have opened up. However technology transfer to the pubic has not been implemented, such that regular public can access and make use of secure and decentralized software. Most blockchain solutions till date deal with financial applications or monetary transactions, which may not be helpful or be accessible to the general public, especially the lower levels of the financial society. Medi-Chain is a people-first medical blockchain with a usable desktop application and interface which makes use of cutting-edge blockchain technology along with BFT consensus protocols to ensure highly secure and private medical data records. This paper aims to bring about a change in how blockchains-as-a-service is perceived and how adoption of new technology is largely based on usability and ease of adoption.
Blockchain interoperability, which allows state transitions across different\nblockchain networks, is critical functionality to facilitate major blockchain\nadoption. Existing interoperability protocols mostly focus on atomic token\nexchange between blockchains. However, as blockchains have been upgraded from\npassive distributed ledgers into programmable state machines (thanks to smart\ncontracts), the scope of blockchain interoperability goes beyond just token\nexchange. In this paper, we present HyperService, the first platform that\ndelivers interoperability and programmability across heterogeneous blockchains.\nHyperService is powered by two innovative designs: (i) a developer-facing\nprogramming framework that allows developers to build cross-chain applications\nin a unified programming model; and (ii) a secure blockchain-facing\ncryptography protocol that provably realizes those applications on blockchains.\nWe implement a prototype of HyperService in about 35,000 lines of code to\ndemonstrate its practicality. Our experiment results show that HyperService\nimposes reasonable latency, in order of seconds, on the end-to-end execution of\ncross-chain applications\n
Dinh C. Nguyen, Pubudu N. Pathirana, Ming Ding, Aruna Seneviratne
The blockchain technology is taking the world by storm. Blockchain with its decentralized, transparent and secure nature has emerged as a disruptive technology for the next generation of numerous industrial applications. One of them is Cloud of Things enabled by the combination of cloud computing and Internet of Things. In this context, blockchain provides innovative solutions to address challenges in Cloud of Things in terms of decentralization, data privacy and network security, while Cloud of Things offer elasticity and scalability functionalities to improve the efficiency of blockchain operations. Therefore, a novel paradigm of blockchain and Cloud of Things integration, called BCoT, has been widely regarded as a promising enabler for a wide range of application scenarios. In this article, we present a state-of-the-art review on the BCoT integration to provide general readers with an overview of the BCoT in various aspects, including background knowledge, motivation, and integrated architecture. Particularly, we also provide an in-depth survey of BCoT applications in different use-case domains such as smart healthcare, smart city, smart transportation and smart industry. Then, we review the recent BCoT developments with the emerging blockchain and cloud platforms, services, and research projects. Finally, some important research challenges and future directions are highlighted to spur further research in this promising area.
In the digital world, the crypto currency has to do with the use of tokens based on the distributed ledger technology in a secure manner. Crypto currency can be a resource on a block chain network or can be seen as a tool to perform the transactions ensuring the privacy and security. Data may be available in temporal or text format. This paper describes about the distributed architecture for secure and attack-resilient bit coin-based crypto currency transactions for classified temporal and text data. The temporal data may be voice, sound or graphical information basing on the time series. If the data available is temporal this work describes about how it can be classified into a processed form. In this context, this paper describes the process of converting temporal data into text data. Further, the paper describes about the process of ensuring the security. This paper describes about the methodologies of cryptography-based hashing, attack-resilient nonce generation and verifiable encryption techniques for the construction of resilient transactions against stealthy data-integrity attack.
Pranab Kumar Bharimalla, S. Praharaj, Infosys Limited, Bhubaneswar, INDIA, Satya Ranjan Dash
Blockchain was first introduced to the world in a form of crypto currency. Since then it’s grabbing popularity day by day and has already started changing lifestyle and business process in some areas. The Blockchain is a data structure, and consists of time-stamped list of blocks, used to create a digitally secured, transactional ledger that, facilitates the process of recording transactions and tracking assets in a distributed business network instead of resting with a single provider. It brings a paradigm shift from the conventional way of storing transactional data, exchanging value, assets decentralizing and sharing data across a large network of untrusted participants without intervention of any centralized trusted agency, but still building a trusted system without compromising data integrity, security and reliability. This paper is based on survey of different consensus mechanisms already available so far and an introduce our own approach to tack one of the security threats by introducing a Neural Network to the consensus mechanism of Blockchain.
There is no doubt that Internet of Things (IoT) and blockchain technology will a major impact in the automated futuristic world. Even though the usage of IoT is increasing rapidly, it is riddled with scalability, security, privacy and integrity issues. Even though blockchain was initially created for managing cryptocurrencies, its decentralised nature, higher security, integrity and privacy has led to being integrated with IoT in order to improve it. There are multiple challenges arising from this integration which increases the complexities. It is necessary to study these challenges involved in this integration before carrying it out. Hence, this paper has carried out a systematic study of the various challenges involved in IoT individually and also the advantages and challenges of integrating it with the blockchain system.
Ten years after the introduction of the Bitcoin protocol, an increasing number of art-tech startups and more or less independent initiatives have begun to explore second-generation blockchains such as Ethereum and the emergent practice of tokenization (i.e., the issuance of new cryptoassets primarily to self-fund decentralized projects) as a means to intervene in the structures and processes underlying the rampant financialization of art. Yet amidst the volatility of the cryptocurrency market, tokenization has been critiqued as a way to reinscribe and proliferate current financial logics in this new space. Acknowledging such critiques, in this essay I foreground the novelty of cryptotokens and blockchains by exploring different examples of how tokenization has been deployed in the art market-milieu. In spite of recent attempts to extend the scarcity-based paradigm to blockchains, I argue that cryptotokens do introduce differences in kind in the ways in which value generation and distribution are expressed and accounted for in digital environments. In this context, artistic approaches to tokenization can illuminate new aspects of the affordances of these technologies, toward the disintermediation of art production and its networked value from the current institutional-financial milieu. This can open up new ways to reimagine and reprogram financial and social relations, and gesture toward new opportunities and challenges for a practice of digital design focused on the ideation and realization of cryptoeconomic systems.
This article argues that, for purposes of the Income Tax Act 58 of 1962, Bitcoin and cryptocurrencies operating in a like manner are incorporeal property with a comparable value in real currency. The fundamental basis for the advancement of the hypothesis that such cryptocurrencies give rise to protectable proprietary rights are: (i) the rights exist digitally in cyberspace; (ii) the rights have value to their users; (iii) the rights are capable of being owned as cyberproperty; (iv) the rights can be transferred electronically by a possessor of a unique public-private cryptography protected keypair, and (v) the rights can be proved by entries in a digital ledger that records the historical chain of ownership transfers. This article argues further that the average, fair market value of the cryptocurrency in South African Rands on the date of its receipt or accrual as a revenue asset must be included in a taxpayer’s gross income. It is further argued that this value ought to be the average price of the cryptocurrency determined with reference to at least two pricing indices commonly used or accepted in the marketplace.
Blockchain technology uses the cryptographic technique to create expanding list of data records called blocks. Along with transaction and timestamp data, each block holds a hash value obtained using cryptographic technique. Blockchain gains importance for its decentralized data transaction and authorization without the need for third-party intervention. Although, it is mostly used in Finance sector these days, due to its inherent ability to protect data it can be applied to every field of computation especially in fields where data transaction is voluminous. Internet of Things (IoT) is one such area where it involves collection, transfer and processing of real time data from objects, humans and sensors to automate various tasks. Hence, this paper reviews the blockchain technology, and how it can be coupled with IoT to overcome the privacy and security issues. This paper first systematically introduces the concept of blockchain technology, its applications along with the need for IoT devices and its implementation. Finally, it discusses the blockchain based IoT (BIoT) its architecture, advantages, challenges in implementation
Royal University of Bhutan was established in 2003 through Royal Charter. RUB is a decentralized university with eight colleges distributed across the country. In the year 2011, RUB became fully autonomous university. After two years of successful autonomy, the RUB was beginning to sense the gradual decline in government funding. This has put to test the future sustainability of the university. Colleges under RUB have saved the funds that was granted by the royal government of Bhutan (RGoB) to sustain in the future as there began gradual decline in grants during the coming years (Rigyal, 2013). This study is aimed to find the present investment policy of the colleges under RUB and recommend investment products for them to generate future sustainable income for the colleges & university. In order to assess the knowledge of the investment, expected return & risk and the preference of the colleges under RUB a set of questionnaire was administered. A total of 20 respondents, including President, finance personal and administrative officer, from 5 colleges (representing more than 60% of colleges) under RUB were taken for the study. Responses reveal the general investment policy of the colleges, present investment avenues adopted and return on them. All these facts were analyzed to propose portfolio for the colleges, which can help them to generate sustainable incomes.
Ayana T. Aspembitova, Ling Feng, Valentin Melnikov, Lock Yue Chew
Bitcoin is the earliest cryptocurrency and among the most successful ones to date. Recently, its dynamical evolution has attracted the attention of the research community due to its completeness and richness in historical records. In this paper, we focus on the detailed evolution of bitcoin trading with the aim of elucidating the mechanism that drives the formation of the bitcoin transaction network. Our empirical investigation reveals that although the temporal properties of the transaction network possesses scale-free degree distribution like many other networks, its formation mechanism is different from the commonly assumed models of degree preferential attachment or wealth preferential attachment. By defining the fitness value of each node as the ability of the node to attract new connections, we have instead uncovered that the observed scale-free degree distribution results from the intrinsic fitness of each node following a power-law distribution. Our finding thus suggests that the "good-get-richer" rather than the "rich-get-richer" paradigm operates within the bitcoin ecosystem. Based on these findings, we propose a model that captures the temporal generative process by means of a fitness preferential attachment and data-driven birth/death mechanism. Our proposed model is able to produce structural properties in good agreement with those obtained from the empirical bitcoin network.
Matteo Troncia, Marco Galici, Mario Mureddu, Emilio Ghiani · 5 authors
The newest Distributed Ledger Technology platforms, which delegate the execution of complex tasks in the form of Smart Contracts, make it possible to devise novel local electricity market frameworks, which are performed in a fully automated fashion. This paper proposes a novel fully automated platform for energy and ancillary service markets in distribution networks, able to run in a decentralized fashion, bypassing the need for a physical central authority. The proposed platform, able to perform the role of Virtual Decentralized Market Authority, shows excellent potential applications in the management of local ancillary service markets in local energy communities of various sizes. The proposed Virtual Decentralized Market Authority showed reasonable running costs and comparable technical management capabilities with respect to a physical, centralized managing authority.
Ethereum has become a widely used platform to enable secure, Blockchain-based financial and business transactions. However, a major concern in Ethereum is the security of its smart contracts. Many identified bugs and vulnerabilities in smart contracts not only present challenges to maintenance of blockchain, but also lead to serious financial loses. There is a significant need to better assist developers in checking smart contracts and ensuring their reliability.In this paper, we propose a web service tool, named SmartEmbed, which can help Solidity developers to find repetitive contract code and clone-related bugs in smart contracts. Our tool is based on code embeddings and similarity checking techniques. By comparing the similarities among the code embedding vectors for existing solidity code in the Ethereum blockchain and known bugs, we are able to efficiently identify code clones and clone-related bugs for any solidity code given by users, which can help to improve the users' confidence in the reliability of their code. In addition to the uses by individual developers, SmartEmbed can also be applied to studies of smart contracts in a large scale. When applied to more than 22K solidity contracts collected from the Ethereum blockchain, we found that the clone ratio of solidity code is close to 90\%, much higher than traditional software, and 194 clone-related bugs can be identified efficiently and accurately based on our small bug database with a precision of 96\%. SmartEmbed can be accessed at \url{http://www.smartembed.net}. A demo video of SmartEmbed is at \url{https://youtu.be/o9ylyOpYFq8}
Access control is a mechanism in computer security that regulates access to the system resources. The current access control systems face many problems, such as the presence of the third-party, inefficiency, and lack of privacy. These problems can be addressed by blockchain, the technology that received major attention in recent years and has many potentials. In this study, we overview the problems of the current access control systems, and then, we explain how blockchain can help to solve them. We also present an overview of access control studies and proposed platforms in the different domains. This paper presents the state of the art and the challenges of blockchain-based access control systems.
Blockchain is a distributed operation and information supervision technology programmed initially for Bitcoin cryptocurrency. The awareness in Blockchain technology is rapidly growing since the notion was invented in the year 2008. The motivation for the concentration in Blockchain is its significant characteristics that deliver security, privacy, and information reliability devoid of any additional system regulating the communications, and consequently it generates fascinating research domains, specifically from the viewpoint of methodological difficulties and restrictions. This study discovers the wide‐ranging Blockchain technology and studies it's perspective with respect to ‘ internet‐of‐things ’ controlled nodes. A resilient prototype method has been programmed that reveals a basic system exhausting Blockchain. The outcome illustrates that the established method is functional in test‐bed environment.