This study aims to explore the current status, potential applications, and future directions of blockchain technology in supply chain management. A literature survey, along with an analytical review, of blockchain-based supply chain research was conducted to better understand the trajectory of related research and shed light on the benefits, issues, and challenges in the blockchain-supply-chain paradigm. A selected corpus comprising 106 review articles was analyzed to provide an overview of the use of blockchain and smart contracts in supply chain management. The diverse industrial applications of these technologies in various sectors have increasingly received attention by researchers, engineers, and practitioners. Four major issues: traceability and transparency, stakeholder involvement and collaboration, supply chain integration and digitalization, and common frameworks on blockchain-based platforms, are critical for future orientation. Traditional supply chain activities involve several intermediaries, trust, and performance issues. The potential of blockchain can be leveraged to disrupt supply chain operations for better performance, distributed governance, and process automation. This study contributes to the comprehension of blockchain applications in supply chain management and provides a blueprint for these applications from the perspective of literature analysis. Future efforts regarding technical adoption/diffusion, block-supply chain integration, and their social impacts were highlighted to enrich the research scope.
Hamda Al Breiki, Muhammad Habib ur Rehman, Khaled Salah, Davor Svetinović
The essence of blockchain smart contracts lies in the execution of business logic code in a decentralized architecture in which the execution outcomes are trusted and agreed upon by all the executing nodes. Despite the decentralized and trustless architectures of the blockchain systems, smart contracts on their own cannot access data from the external world. Instead, smart contracts interact with off-chain external data sources, called oracles, whose primary job is to collect and provide data feeds and input to smart contracts. However, there is always risk of oracles providing corrupt, malicious, or inaccurate data. In this paper, we analyze and present the notion of trust in the oracles used in blockchain ecosystems. We analyze and compare trust-enabling features of the leading blockchain oracle approaches, techniques, and platforms. Moreover, we discuss open research challenges that should be addressed to ensure secure and trustworthy blockchain oracles.
This paper presents research challenges on security and privacy issues in the field of green IoT-based agriculture. We start by describing a four-tier green IoT-based agriculture architecture and summarizing the existing surveys that deal with smart agriculture. Then, we provide a classification of threat models against green IoT-based agriculture into five categories, including, attacks against privacy, authentication, confidentiality, availability, and integrity properties. Moreover, we provide a taxonomy and a side-by-side comparison of the state-of-the-art methods toward secure and privacy-preserving technologies for IoT applications and how they will be adapted for green IoT-based agriculture. In addition, we analyze the privacy-oriented blockchain-based solutions as well as consensus algorithms for IoT applications and how they will be adapted for green IoT-based agriculture. Based on the current survey, we highlight open research challenges and discuss possible future research directions in the security and privacy of green IoT-based agriculture.
Caixiang Fan, Sara Ghaemi, Hamzeh Khazaei, Petr Musı́lek
Blockchain has been envisioned to be a disruptive technology with potential for applications in various industries. As more and more different blockchain platforms have emerged, it is essential to assess their performance in different use cases and scenarios. In this paper, we conduct a systematic survey on the blockchain performance evaluation by categorizing all reviewed solutions into two general categories, namely, empirical analysis and analytical modelling. In the empirical analysis, we comparatively review the current empirical blockchain evaluation methodologies, including benchmarking, monitoring, experimental analysis and simulation. In analytical modelling, we investigate the stochastic models applied to performance evaluation of mainstream blockchain consensus algorithms. Through contrasting, comparison and grouping different methods together, we extract important criteria that can be used for selecting the most suitable evaluation technique for optimizing the performance of blockchain systems based on their identified bottlenecks. Finally, we conclude the survey by presenting a list of possible directions for future research.
Yingying Zhang, Feng Xiong, Yi Xie, Xuan Fan · 5 authors
Recent developments in technology have introduced dramatic changes to the practice of the accounting profession. This paper provides a comprehensive review of current developments in big data, machine learning, artificial intelligence, and blockchain utilized in general business practice and by specialized practitioners in the accounting profession worldwide. This paper explores the evolution of the accounting profession following these recent technological developments and assesses the impact of future developments. Inherent challenges and opportunities posed by these new technologies pertaining to accounting professionals and accounting educators are also examined, including an increased demand for IT professionals with accounting experience as opposed to accounting major graduates. Considering the dramatic changes and developments of AI applications in accounting, this paper reflects how all these technologies and the associated requirements of job candidates will affect the desired capabilities of accounting graduates and provides further discussion regarding what higher institutions and their accounting graduates can do to adopt such changes.
Affaf Shahid, Ahmad Almogren, Nadeem Javaid, Fahad Ahmed Al-Zahrani · 6 authors
Supply chains are evolving into automated and highly complex networks and are becoming an important source of potential benefits in the modern world. At the same time, consumers are now more interested in food product quality. However, it is challenging to track the provenance of data and maintain its traceability throughout the supply chain network. The traditional supply chains are centralized and they depend on a third party for trading. These centralized systems lack transparency, accountability and auditability. In our proposed solution, we have presented a complete solution for blockchain-based Agriculture and Food (Agri-Food) supply chain. It leverages the key features of blockchain and smart contracts, deployed over ethereum blockchain network. Although blockchain provides immutability of data and records in the network, it still fails to solve some major problems in supply chain management like credibility of the involved entities, accountability of the trading process and traceability of the products. Therefore, there is a need of a reliable system that ensures traceability, trust and delivery mechanism in Agri-Food supply chain. In the proposed system, all transactions are written to blockchain which ultimately uploads the data to Interplanetary File Storage System (IPFS). The storage system returns a hash of the data which is stored on blockchain and ensures efficient, secure and reliable solution. Our system provides smart contracts along with their algorithms to show interaction of entities in the system. Furthermore, simulations and evaluation of smart contracts along with the security and vulnerability analyses are also presented in this work.
Guangsheng Yu, Xu Wang, Kan Yu, Wei Ni · 6 authors
The Blockchain technology, featured with its decentralized tamper-resistance based on a Peer-to-Peer network, has been widely applied in financial applications, and even further been extended to industrial applications. However, the weak scalability of traditional Blockchain technology severely affects the wide adoption due to the well-known trillema of decentralization-security-scalability in Blockchains. In regards to this issue, a number of solutions have been proposed, targeting to boost the scalability while preserving the decentralization and security. They range from modifying the on-chain data structure and consensus algorithms to adding the off-chain technologies. Therein, one of the most practical methods to achieve horizontal scalability along with the increasing network size is sharding, by partitioning network into multiple shards so that the overhead of duplicating communication, storage, and computation in each full node can be avoided. This paper presents a survey focusing on sharding in Blockchains in a systematic and comprehensive way. We provide detailed comparison and quantitative evaluation of major sharding mechanisms, along with our insights analyzing the features and restrictions of the existing solutions. We also provide theoretical upper-bound of the throughput for each considered sharding mechanism. The remaining challenges and future research directions are also reviewed.
Blockchain (e.g., Bitcoin and Ethereum) has drawn much attention and has been widely-deployed in recent years. However, blockchain scalability is emerging as a challenging issue. This paper outlines the existing solutions to blockchain scalability, which can be classified into two categories: first layer and second layer solutions. First layer solutions propose modifications to the blockchain (i.e., changing the blockchain structure, such as block size) while second layer solutions propose mechanisms that are implemented outside of the blockchain. In particular, we focus on sharding as a promising first layer solution to the scalability issue; the basic idea behind sharding is to divide the blockchain network into multiple committees, each processing a separate set of transactions. More specifically, (a) we propose a taxonomy based on committee formation and intra-committee consensus; and (b) we compare the main existing sharding-based blockchain protocols. We also present a performance-based comparative analysis (i.e., throughput and latency), of the advantages, and disadvantages in existing scalability solutions.
The term decentralized finance (DeFi) refers to an alternative financial infrastructure built on top of the Ethereum blockchain. DeFi uses smart contracts to create protocols that replicate existing financial services in a more open, interoperable, and transparent way. This article highlights opportunities and potential risks of the DeFi ecosystem. I propose a multi-layered framework to analyze the implicit architecture and the various DeFi building blocks, including token standards, decentralized exchanges, decentralized debt markets, blockchain derivatives, and on-chain asset management protocols.
The unprecedented outbreak of the 2019 novel coronavirus, termed as COVID-19 by the World Health Organization (WHO), has placed numerous governments around the world in a precarious position. The impact of the COVID-19 outbreak, earlier witnessed by the citizens of China alone, has now become a matter of grave concern for virtually every country in the world. The scarcity of resources to endure the COVID-19 outbreak combined with the fear of overburdened healthcare systems has forced a majority of these countries into a state of partial or complete lockdown. The number of laboratory-confirmed coronavirus cases has been increasing at an alarming rate throughout the world, with reportedly more than 3 million confirmed cases as of 30 April 2020. Adding to these woes, numerous false reports, misinformation, and unsolicited fears in regards to coronavirus, are being circulated regularly since the outbreak of the COVID-19. In response to such acts, we draw on various reliable sources to present a detailed review of all the major aspects associated with the COVID-19 pandemic. In addition to the direct health implications associated with the outbreak of COVID-19, this study highlights its impact on the global economy. In drawing things to a close, we explore the use of technologies such as the Internet of Things (IoT), Unmanned Aerial Vehicles (UAVs), blockchain, Artificial Intelligence (AI), and 5G, among others, to help mitigate the impact of COVID-19 outbreak.
Blockchain and other Distributed Ledger Technologies (DLTs) have evolved significantly in the last years and their use has been suggested for numerous applications due to their ability to provide transparency, redundancy and accountability. In the case of blockchain, such characteristics are provided through public-key cryptography and hash functions. However, the fast progress of quantum computing has opened the possibility of performing attacks based on Grover's and Shor's algorithms in the near future. Such algorithms threaten both public-key cryptography and hash functions, forcing to redesign blockchains to make use of cryptosystems that withstand quantum attacks, thus creating which are known as post-quantum, quantum-proof, quantum-safe or quantum-resistant cryptosystems. For such a purpose, this article first studies current state of the art on post-quantum cryptosystems and how they can be applied to blockchains and DLTs. Moreover, the most relevant post-quantum blockchain systems are studied, as well as their main challenges. Furthermore, extensive comparisons are provided on the characteristics and performance of the most promising post-quantum public-key encryption and digital signature schemes for blockchains. Thus, this article seeks to provide a broad view and useful guidelines on post-quantum blockchain security to future blockchain researchers and developers.
Due to the proliferation of ICT during the last few decades, there is an exponential increase in the usage of various smart applications such as smart farming, smart healthcare, supply-chain & logistics, business, tourism and hospitality, energy management etc. However, for all the aforementioned applications, security and privacy are major concerns keeping in view of the usage of the open channel, i.e., Internet for data transfer. Although many security solutions and standards have been proposed over the years to enhance the security levels of aforementioned smart applications, but the existing solutions are either based upon the centralized architecture (having single point of failure) or having high computation and communication costs. Moreover, most of the existing security solutions have focussed only on few aspects and fail to address scalability, robustness, data storage, network latency, auditability, immutability, and traceability. To handle the aforementioned issues, blockchain technology can be one of the solutions. Motivated from these facts, in this paper, we present a systematic review of various blockchain-based solutions and their applicability in various Industry 4.0-based applications. Our contributions in this paper are in four fold. Firstly, we explored the current state-of-the-art solutions in the blockchain technology for the smart applications. Then, we illustrated the reference architecture used for the blockchain applicability in various Industry 4.0 applications. Then, merits and demerits of the traditional security solutions are also discussed in comparison to their countermeasures. Finally, we provided a comparison of existing blockchain-based security solutions using various parameters to provide deep insights to the readers about its applicability in various applications.
Blockchain-based decentralized cryptocurrencies have drawn much attention and been widely-deployed in recent years. Bitcoin, the first application of blockchain, achieves great success and promotes more development in this field. However, Bitcoin encounters performance problems of low throughput and high transaction latency. Other cryptocurrencies based on proof-of-work also inherit the flaws, leading to more concerns about the scalability of blockchain. This paper attempts to cover the existing scaling solutions for blockchain and classify them by level. In addition, we make comparisons between different methods and list some potential directions for solving the scalability problem of blockchain.
Consider a set of parties invited to execute a protocol $Π$. The protocol will incur some cost to run while in the end (or at regular intervals), it will populate and update local tables that assign (virtual) rewards to participants. Each participant aspires to offset the costs of participation by these virtual payoffs that are provided in the course of the protocol. In this setting, we introduce and study a notion of coalition-safe equilibrium. In particular, we consider a strategic coalition of participants that is centrally coordinated and potentially deviates from $Π$ with the objective to increase its utility with respect to the view of {\em at least one} of the other participants. The protocol $Π$ is called a coalition-safe equilibrium with virtual payoffs (EVP) if no such protocol deviation exists. We apply our notion to study incentives in blockchain protocols. We proceed to use our framework to provide a unified picture of incentives in the Bitcoin blockchain, for absolute and relative rewards based utility functions, as well as prove novel results regarding incentives of the Fruitchain blockchain protocol [PODC 2017] showing that the equilibrium condition holds for collusions up to $n-1$ players for absolute rewards based utility functions and less than $n/2$ for relative rewards based utility functions, with the latter result holding for any "weakly fair" blockchain protocol, a new property that we introduce and may be of independent interest.
The electronic tendering process is rapidly growing popularity among private and public sectors for its efficiency and convenience. An end to end fair and transparent tendering process is desirable for all stakeholders and the proper business environment. Researchers and business entities are continuously working to improve its quality. In general, while offering a tender, an enterprise usually maintains the following steps [1].
Social networking pages authenticate by blockchain technology, through authenticating personal information and profile pages in the form of block and then distributing them with Blockchain to become a trusted reference point. To identified and verified social network accounts. This research proposed an effective and easy technical mechanism to authenticate the personal pages on social networks. Using this mechanism, anyone can authenticate any account on social networks, as well as increasing the possibility of making sure of the real individual behind social networking accounts. Moreover, this technique will show the fake accounts in order to reach a more confident and secure social network environment. Blockchain technique requires only a simple update to the characteristics of its platforms by developers, which is only a participatory mechanism between Blockchain and personal information. It is then combined with personal pages, to indicate that these pages contain the real personal information of the account holder, which is stored in an encrypted block that is difficult to modify, copy, or steal.
Blockchain is going to be the most fundamental technology, and will change the world — going forward. In fact, the revolution has already begun. The birth of Industry 4.0 aka the Fourth Industrial Relution (I4.0), has created a need for autonomous and integrated, secure manufacturing systems. The current smart systems lack the decentralized decision making and real-time communication infrastructure, which is a condition for adaptive, smart manufacturing systems. In this paper, an autonomous, secure and collaborative platform based on Blockchain technology, is presented to adapt to such results. In support with Internet of Things (IoT) and cloud services, a Blockchain Driven Cyber Physical Production System (BDCPS) architecture is designed to communicate with machines, users, devices, suppliers and other peers. Using the Smart Contracts feature and trust-less peer-to-peer decentralized ledger feature, BDCPS will validate the claim with a small-scale real-life Blockchain with IoT system. This implementation case study will be running a private Blockchain on a single board computer, and bridged to a microcontroller containing IoT sensors. The applications of this system in automotive manufacturing industry are presented, to proceed towards Industry 4.0.
Günümüzde kripto para birimlerinin önemi gittikçe artmaktadır. Kripto para birimleri sanal oyun platformlarında kullanılırken, şu an pek çok kurum ve kuruluş tarafından ödeme aracı olarak kullanılmaktadır. Güvenlik risklerine karşı blockchain (Blok Zinciri) adı verilen algoritması ile üretimi sağlanmaktadır. Kripto para fiyatlarının doğru olarak tahmin edilmesi yatırımcı ve karar vericiler açısından büyük önem taşımaktadır. Bu çalışma kapsamında en çok kullanılan dört kripto para birimine (Bitcoin, Ethereum, Ripple, Litecoin) ait fiyat değerleri tahmin edilmiştir. Çoklu kırılma testinden yararlanılarak her seriye ait kırılmalar belirlenerek analiz genişletilmiştir. Ele alınan sanal para değerlerini doğru bir şekilde tahmin etmek amacıyla hem klasik zaman serisi modellerinden hem de üç farklı tür yapay sinir ağı modelinden faydalanılmıştır. Ayrıca elde edilen tahminler üzerinde basit birleştirilme teknikleri uygulanmıştır. Rassal yürüyüşün egemen olduğu bu seriler arasından, özellikle işlem hacmi ve bilinilirliği en fazla olan Bitcoin sanal parasında rassal yürüyüş modelinden daha iyi sonuçlar elde edildiği gözlemlenmiştir.
Blockchain technologies are becoming more popular in securing the sensitive data such as government holding citizens’ s wealth, health and personal information. A blockchain is a shared encrypted data of records, consisting of a ledger of transactions. As the data stored in blockchain is tamper proof, it is proposed to implement new Aadhar enrolments with P2P Blockchains and migrate the existing centralized Aadhar personnel’s personal data from the conventional RDBMS / Big data system repositories to distributed ledger technologies by creating private blockchains. In this paper, we will discuss how to provide security for Aadhar card enrolment data using blockchain architectures. A blockchain-based Aadhaar would help UIDAI in truly complying with the data protection and privacy stipulations outlined in the Right to Privacy Act judgment
CFDD (CounterFeit Drug Detection) using Blockchain in the Pharmaceutical Industry - written by Kavita Kumari , Kavita Saini published on 2019/12/31 download full article with reference data and citations
We use a GARCH dummy model to study the influence of calendar effects on daily conditional returns and volatility of Bitcoin during the period 2013–2019. The Halloween, day-of-the-week (DOW), and month-of-the-year (MOY) effects are analyzed. Our results reveal no evidence of a Halloween calendar anomaly. A classical DOW effect is not present in Bitcoin returns, however, we find significantly lower risk over the weekend whilst in the beginning of the week Bitcoin's volatility is more intense. Moreover, supporting evidence of a reverse January effect is detected. Our results also show that investors’ risk drops substantially in September.
A deletable blockchain has been proposed recently to change the immutability of the traditional blockchain. However, the users' identities and transaction contents are all public in the scheme, and the public data may reveal the users' privacy. In order to protect the privacy of the users, we propose a privacy-protected deletable blockchain based on the proof-of-space consensus mechanism, which does not rely on complex cryptographic tools or any trusted party. In order to satisfy full transparency and accountability in an anonymous environment, we use a traceable ring signature or a Pedersen commitment scheme to disclose the users' real identities or the real transaction contents respectively according to different deletion reasons. During the deletion process, we propose a linkable multi-signature scheme, which allows multiple users to generate a valid signature by using their one-time addresses as pseudonyms to protect their identity privacy. Moreover, the proposed multi-signature scheme can link two sub-signatures if they are generated by the same malicious user. Finally, we simulate the generation and deletion process of a block under the proof-of-space consensus mechanism and give the time of generating and deleting a block. The experimental results prove the efficiency and feasibility of our proposed scheme.
There has never been enough humanitarian funding. Needs have always gone unmet, and the international community has long sought ways to fix this problem. Inadequate information, poor infrastructure and lack of sufficient human and financial resources are hampering the implementation of early warning systems in Africa(Omulo,1998).This is prompted by the sense that inadequate resources are being over-stretched to cover a wider scope of needs, in a greater number of crises. Sustainability must now become a fundamental feature of humanitarian action. This will result in generation of adequate resources to carry out operations; ability to pay own core costs sustainably thereby making Kenya Red Cross Society a more attractive proposition to donors; realization of growth in the society ;funding of programs that are of priority to Kenya Red Cross and additional resources for re-investment. As indicated, sustainability and growth of Kenya Red Cross Society is dependent on its ability to finance its core costs from its own income generating initiatives. The society thus has to internalize the economic engine which involves resource mobilization, funding diversification, grant management, investing in income generating activities thus reducing dependency on donor funding, realizing income from subsidiaries(E-plus and Red Court),lobbying for funding from the government and the general public, decentralizing the resource base and developing a resource mobilization unit The overall objective of the study is to examine the impact of humanitarian funds by the Kenya Red Cross Society on reconstruction and development programs. . This study focused on Systemization of innovative ‘crisis modifier' approaches, and other sustainable financing approaches, to blend and switch between humanitarian and development funding as needed in protracted settings. This study is based on resource mobilization and investment in income generating activities. There is an intense competition for scarce humanitarian funds as the Kenyan humanitarian crises industry comprises many players all competing for limited resources. Resource availability on the other hand dictates the level and intensity of disaster mitigation and coupled with donors' preferences, KCRS as a major player has to continuously demonstrate its capabilities and intensify efforts that ensure sustainable funding
The Blockchain is a distributed database of all transactions or digital events that is maintained as Blocks. These transaction records that are executed between parties are stored as blocks in Blockchain and shared among parties that maintain the blocks. Each Block is analyzed, verified and stored by the parties who are part of the network/system. Each block contains the details of a single transaction and a hash key of the previous block. Digital Crypto Currency and Bitcoin use Blockchain as its backbone. By design, Blockchains are much secured and the technology ensures flawless record keeping. The Crypto Currency, Bitcoin which is used as a decentralized digital currency shall be transacted peer-to-peer without any third party involvement. Other areas like financial transactions, identity management, food traceability, medical records, even election processes shall be secured using Blockchain. Electronic payments have made a major breakthrough in Indian banking sector and continue to grow with more innovations in the enhancements to the existing system. Slowly Electronic payments are replacing paper based transactions which saves time and cost. Volume of transactions has also increased with more transparency and the sector is showcasing good progress. Introduction of Bitcoin and crypto currencies in Finance and Banking sectors have brought in a paradigm shift on the fundamental transaction processes of this sector. Essential elements of trade, ownership and trust are ensured through Blockchain which makes a disruptive intervention on whole transaction management model. Constructive and critical exploration of this technology in the context of India will bring out more prospective on how this technology shall be leveraged. This paper will present the current state of Blockchain adoption in India and will cover the challenges and opportunities in this space..