The use of low-cost sensors in IoT over high-cost devices has been considered less expensive. However, these low-cost sensors have their own limitations such as the accuracy, quality, and reliability of the data collected. Fog computing offers solutions to those limitations; nevertheless, owning to its intrinsic distributed architecture, it faces challenges in the form of security of fog devices, secure authentication and privacy. Blockchain technology has been utilised to offer solutions for the authentication and security challenges in fog systems. This paper proposes an authentication system that utilises the characteristics and advantages of blockchain and smart contracts to authenticate users securely. The implemented system uses the email address, username, Ethereum address, password and data from a biometric reader to register and authenticate users. Experiments showed that the proposed method is secure and achieved performance improvement when compared to existing methods. The comparison of results with state-of-the-art showed that the proposed authentication system consumed up to 30% fewer resources in transaction and execution cost; however, there was an increase of up to 30% in miner fees.
M.Phil. Dr. S. P. Priyadharshini MCA., A. Rajeswari B.Sc.
Designing an electronic voting system is the greatest test, particularly in India. It needs to fulfill every one of the lawful functionalities and carefully designed system. Blockchain technology is a dispersed sort networks numerous applications like Electronic clinical records, IoT and E-voting. Electronic voting (E-voting) plot is a utilization situation where all credits of blockchain can offer an instrument for an open, fair and all around unquestionable constituent interaction. In this paper, propose Ethereum Technique an E-voting system that uses the blockchain technology. The proposed system is enabled by Ethereum Technique, including one server deals with the whole system and different handles all blockchain-related demands. The e-voting system intends to dispense with the bottlenecks obvious in the manual voting system, for example, the extended enlistment process, superfluous transportation, and political decision viciousness and at last the inconceivability of the votes. The outcomes acquired from resulting tests were extremely noteworthy as far as time, security and accuracy when contrasted with the manual system.
Widespread applications of 5G technology have prompted the outsourcing of computation dominated by the Internet of Things (IoT) cloud to improve transmission efficiency, which has created a novel paradigm for improving the speed of common connected objects in IoT. However, although it makes it easier for ubiquitous resource-constrained equipment that outsources computing tasks to achieve high-speed transmission services, security concerns, such as a lack of reliability and collusion attacks, still exist in the outsourcing computation. In this paper, we propose a reliable, anti-collusion outsourcing computation and verification protocol, which uses distributed storage solutions in response to the issue of centralized storage, leverages homomorphic encryption to deal with outsourcing computation and ensures data privacy. Moreover, we embed outsourcing computation results and a novel polynomial factorization algorithm into the smart contract of Ethereum, which not only enables the verification of the outsourcing result without a trusted third party but also resists collusion attacks. The results of the theoretical analysis and experimental performance evaluation demonstrate that the proposed protocol is secure, reliable, and more effective compared with state-of-the-art approaches.
Mitchell Olsthoorn, Dimitri Stallenberg, Arie van Deursen, Annibale Panichella
Ethereum is the largest and most prominent smart contract platform. One key property of Ethereum is that once a contract is deployed, it can not be updated anymore. This increases the importance of thoroughly testing the behavior and constraints of the smart contract before deployment. Existing approaches in related work either do not scale or are only focused on finding crashing inputs. In this tool demo, we introduce SynTest-Solidity, an automated test case generation and fuzzing framework for Solidity. SynTest-Solidity implements various metaheuristic search algorithms, including random search (traditional fuzzing) and genetic algorithms (i.e., NSGA-II, MOSA, and DynaMOSA). Finally, we performed a preliminary empirical study to assess the effectiveness of SynTest-Solidity in testing Solidity smart contracts.
BACKGROUND: A clinical trial management system (CTMS) is a suite of specialized productivity tools that manage clinical trial processes from study planning to closeout. Using CTMSs has shown remarkable benefits in delivering efficient, auditable, and visualizable clinical trials. However, the current CTMS market is fragmented, and most CTMSs fail to meet expectations because of their inability to support key functions, such as inconsistencies in data captured across multiple sites. Blockchain technology, an emerging distributed ledger technology, is considered to potentially provide a holistic solution to current CTMS challenges by using its unique features, such as transparency, traceability, immutability, and security. OBJECTIVE: This study aimed to re-engineer the traditional CTMS by leveraging the unique properties of blockchain technology to create a secure, auditable, efficient, and generalizable CTMS. METHODS: A comprehensive, blockchain-based CTMS that spans all stages of clinical trials, including a sharable trial master file system; a fast recruitment and simplified enrollment system; a timely, secure, and consistent electronic data capture system; a reproducible data analytics system; and an efficient, traceable payment and reimbursement system, was designed and implemented using the Quorum blockchain. Compared with traditional blockchain technologies, such as Ethereum, Quorum blockchain offers higher transaction throughput and lowers transaction latency. Case studies on each application of the CTMS were conducted to assess the feasibility, scalability, stability, and efficiency of the proposed blockchain-based CTMS. RESULTS: A total of 21.6 million electronic data capture transactions were generated and successfully processed through blockchain, with an average of 335.4 transactions per second. Of the 6000 patients, 1145 were matched in 1.39 seconds using 10 recruitment criteria with an automated matching mechanism implemented by the smart contract. Key features, such as immutability, traceability, and stability, were also tested and empirically proven through case studies. CONCLUSIONS: This study proposed a comprehensive blockchain-based CTMS that covers all stages of the clinical trial process. Compared with our previous research, the proposed system showed an overall better performance. Our system design, implementation, and case studies demonstrated the potential of blockchain technology as a potential solution to CTMS challenges and its ability to perform more health care tasks.
Privacy and data security have become the new hot topic for regulators in recent years. As a result, Federated Learning (FL) (also called collaborative learning) has emerged as a new training paradigm that allows multiple, geographically distributed nodes to learn a Deep Learning (DL) model together without sharing their data. Blockchain is becoming a new trend as data protection and privacy are concerns in many sectors. Technology is leading the world and transforming into a global village where everything is accessible and transparent. We have presented a blockchain enabled security model using FL that can generate an enhanced DL model without sharing data and improve privacy through higher security and access rights to data. However, existing FL approaches also have unique security vulnerabilities that malicious actors can exploit and compromise the trained model. The FL method is compared to the other known approaches. Users are more likely to choose the latter option, i.e., providing local but private data to the server and using ML apps, performing ML operations on the devices without benefiting from other usersâ data, and preventing direct access to raw data and local training of ML models. FL protects data privacy and reduces data transfer overhead by storing raw data on devices and combining locally computed model updates. We have investigated the feasibility of data and model poisoning attacks under a blockchain-enabled FL system built alongside the Ethereum network and the traditional FL system (without blockchain). This work fills a knowledge gap by proposing a transparent incentive mechanism that can encourage good behavior among participating decentralized nodes and avoid common problems and provides knowledge for the FL security literature by investigating current FL systems.
Blockchain technology spread very quickly during the last few years and has become one of the most popular trends among the research and developers community. In particular, the Ethereum blockchain is one of the most supported and used for developing smart contracts, which are informatics protocols that provide a higher level of security than traditional contracts and reduce other transaction costs associated with the bargaining practice. Nowadays, the transaction number associated with smart contracts deploying increased widely, and it is difficult for researchers and developers to keep track of programming trends. This work proposes a dataset containing only specific categories of smart contracts associated with the most popular trends of the last five years. Mainly, the proposed collection of programs contains Token and Non-Fungible-Token programs, whose popularity has increased a lot since their first appearance on the blockchain.
Shunhui Ji, Shaoqing Zhu, Pengcheng Zhang, Hai Dong · 5 authors
Smart contracts are commonly deployed for safety-critical applications, the quality assurance of which has been a vital factor. Test cases are standard means to ensure the correctness of data flows in smart contracts. To more efficiently generate test cases with high coverage, we propose an improved genetic algorithm-based test-case generation approach for smart contract data flow testing. Our approach introduces the theory of particle swarm optimization into the genetic algorithm, which reduces the influence brought by the randomness of genetic operations and enhances its capability to find global optima. A set of 30 real smart contracts deployed on Ethereum and GitHub is collected to perform the experimental study, on which our approach is compared with three baseline approaches. The experimental results show that, in most cases, the coverage of the test cases generated by our approach is significantly higher than the baseline approaches with relatively lower numbers of iterations and lower execution time.
Decentralized finance (DeFi) in Ethereum is a financial ecosystem built on the blockchain that has locked over 200 billion USD until April 2022. All transaction information is transparent and open when transacting through the DeFi protocol, which has led to a series of attacks. Several studies have attempted to optimize it from both economic and technical perspectives. However, few works analyze the vulnerabilities and optimizations of the entire DeFi system. In this paper, we first systematically analyze vulnerabilities related to DeFi in Ethereum at several levels, then we investigate real-world attacks. Finally, we summarize the achievements of DeFi optimization and provide some future directions.
Front-running attacks, which benefit from advanced knowledge of pending transactions, have proliferated in the blockchain space since the emergence of decentralized finance. Front-running causes devastating losses to honest participants and continues to endanger the fairness of the ecosystem. We present Flash Freezing Flash Boys (F3B), a blockchain architecture that addresses front-running attacks by using threshold cryptography. In F3B, a user generates a symmetric key to encrypt their transaction, and once the underlying consensus layer has finalized the transaction, a decentralized secret-management committee reveals this key. F3B mitigates front-running attacks because, before the consensus group finalizes it, an adversary can no longer read the content of a transaction, thus preventing the adversary from benefiting from advanced knowledge of pending transactions. Unlike other mitigation systems, F3B properly ensures that all unfinalized transactions, even with significant delays, remain private by adopting per-transaction protection. Furthermore, F3B addresses front-running at the execution layer; thus, our solution is agnostic to the underlying consensus algorithm and compatible with existing smart contracts. We evaluated F3B on Ethereum with a modified execution layer and found only a negligible (0.026%) increase in transaction latency, specifically due to running threshold decryption with a 128-member secret-management committee after a transaction is finalized; this indicates that F3B is both practical and low-cost.
Abstract: Blockchain Technology becoming popular with time giving rise to Web 3.0 and this technology will change the way we see the Internet. Blockchain is a decentralized, digitally dis- tributed immutable ledger that allows real-time communication to happen securely; this is the reason we need blockchain in a social networking websites as these websites keep the data on centralized servers that can be risky as the data can easily be stolen and can easily be distributed with third parties without the need of users consent. But with the help of Blockchain and DApps, we can create a reliable and efficient way to share messages and media on secured networks without any third party interference. In this paper, we are going to discuss how we make use of smart contracts and peer-to-peer networks like Ethereum to create such applications and allow users to share their messages and other forms of information without any fear of data getting lost or being shared without user consent, we also going to discuss how this method is different from the current method which social networking websites use to secure users data, and how Web 3.0 is going to be different from current Web 2.0 in terms of a social network. Index Terms: decentralization, blockchain, Apps(Decentralized applications), Ethereum
Anna Vacca, Michele Fredella, Andrea Di Sorbo, Corrado Aaron Visaggio · 5 authors
Blockchain technology is becoming increasingly popular, and smart contracts (i.e., programs that run on top of the blockchain) represent a crucial element of this technology. In particular, smart contracts running on Ethereum (i.e., one of the most popular blockchain platforms) are often developed with Solidity, and their deployment and execution consume gas (i.e., a fee compensating the computing resources required). Smart contract development frequently involves code reuse, but poor readable smart contracts could hinder their reuse. However, writing readable smart contracts is challenging, since practices for improving the readability could also be in contrast with optimization strategies for reducing gas consumption. This paper aims at better understanding (i) the readability aspects for which traditional software and smart contracts differ, and (ii) the specific smart contract readability features exhibiting significant relationships with gas consumption. We leverage a set of metrics that previous research has proven correlated with code readability. In particular, we first compare the values of these metrics obtained for both Solidity smart contracts and traditional software systems (written in Java). Then, we investigate the correlations occurring between these metrics and gas consumption and between each pair of metrics. The results of our study highlight that smart contracts usually exhibit lower readability than traditional software for what concerns the number of parentheses, inline comments, and blank lines used. In addition, we found some readability metrics (such as the average length of identifiers and the average number of keywords) that significantly correlate with gas consumption.
Non-fungible tokens (NFTs) are transferrable rights to digital assets, such as images, videos, or music. The phenomenon and its markets have grown significantly since early 2021. The number of NFT marketplaces has been rising continuously since a couple of years. Majority of them employ centralized systems for storage of digital assets (files). This is contradictory to the notion of decentralized systems. In this project we propose a secure platform for trading digital assets in the form of Non-Fungible tokens. It will enable the users to create new digital assets and trade them in exchange of Ethereum-based cryptocurrency. Along with this, we aim to explore technical feasibility of a decentralized file system (using IPFS protocol) for storing the digital assets in a more secured way. In this way, we attempt to address the issue of file storage. Also, this project is an attempt to advocate the use of block chain technology.
Vishal Wanve, Charudutta Sawant, Rohit Sonawane, H. K. Pathak
Real Estate is a wide area consisting of a physical piece of land and the developments on it such as buildings, roads, and other infrastructures. Real Estate can be classified based on the purpose of usage of the property i.e. Residential, Commercial, or Industrial. Since longtime real estate is considered the most secure investment for good returns. But several issues arise in the field of property transactions which are based on the trust that the buyer or seller has in a third-party middleman/broker as well as frauds, inaccurate market statistics, time-consuming processes as well as high processing fees charged by the middlemen/broker. To provide a solution problem a decentralized web application for real estate transactions is proposed in the project. To attain the solution, in this project we propose to design and develop a decentralized web application using blockchain and smart contract technology that avails property buyers and sellers to interact with the help of a private Ethereum network and deploy smart contracts which create a precise and transparent digital property transaction process. This results in the advantages over traditional real estate systems by neglecting the requirement of non-trusted third-party entities, reducing transaction processes as well as transaction costs.
Marcel C. Minutolo, Werner Kristjanpoller, Prakash L. Dheeriya
The importance of cryptocurrency to the global economy is increasing steadily, which is evidenced by a total market capitalization of over $2.18T as of December 17, 2021, according to coinmarketcap.com (Coin, 2021). Cryptocurrencies are too confusing for laymen and require more investigation. In this study, we analyze the impact that the effective reproductive rate, an epidemiological indicator of the spread of COVID-19, has on both the price and trading volume of eight of the largest digital currencies-Bitcoin, Ethereum, Tether, Ripple, Litecoin, Bitcoin Cash, Cardano, and Binance. We hypothesize that as the rate of spread decreases, the trading price of the digital currency increases. Using Generalized Autoregressive Conditional Heteroskedasticity models, we find that the impact of the spread of COVID-19 on the price and trading volume of cryptocurrencies varies by currency and region. These findings offer novel insight into the cryptocurrency market and the impact that the viral spread of COVID-19 has on the value of the major cryptocurrencies.
RICARDO CARREĂO AGUILERA, Miguel Patiño-Ortiz, JuliĂĄn Patiño-Ortiz, Erick VelĂĄzquez Lozada
Initial Crypto-Token Offering (ICO) strategy has worked so far to fund any project. In this scheme, the ICO launches a token playing the role of a stockholderâs share; the more the people buy tokens, the more the funding for the projects. The stakeholders also earn money if the project gains more reliability and more people buy this token. In other words, an ICO strategy works based on either selling or buying of tokens in the areas of security, utility, equity, etc. However, this paperâs focus is only on using oracles and Hyperledger, which means that there is no need to launch a token, instead it uses the network blockchain benefits, particularly oracles and the Ethereum virtual machine, i.e. not the Ethereum blockchain platform but its virtual machine. Since this is a proposal for governmental or corporate usage, the Hyperledger and oracles strategy fits better for this application. Funds for this use-case are gathered in the healthcare field, specifically to reduce the COVID-19 pandemic. The systemâs reliability is the core for attracting investors and donors to fund the system if it guarantees that resources will get to the right destiny. DAPP is based on a smart contract aligned with the smart societies concept to ensure system sustainability.
Digitization of a secure electoral system capable of ensuring fairness and privacy has been a long-standing challenge for a variety of reasons. One is the system's reliance on a third-party organization to manage and verify election results, rendering it insecure. There is a possibility that data will be altered during the election process. As a result, a decentralized e-voting system application capable of verification will be developed in this work using blockchain technology. The Ethereum network and the Truffle framework will be used to implement smart contracts as self-executing electoral agreements. The Ganache (local blockchain) network design demonstrated that the prototype is capable of recording every voting transaction on the network without the use of a central database. The voter can verify the election result by inspecting each voting transaction on the local blockchain. The proposed design will ensure that all voting transactions are stored in a decentralized database, ensuring that no administrative control over the ballot is exercised.
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Mohammad Salahuddin, Priyesh Kadbe, Rajat Wanjarkar
In place of traditional electoral systems, the implementation of e-voting systems is widely adopted which still has major problems in the results. Online voting is an alternative to the old paper voting system and today's popular Electronic Vote Machine (EVM). E-voting systems are very susceptible to manipulation issues, such as alteration of election results by hacking or by the manufacturer of the voting system. To solve this problem, we use distributed ledger technology to create a voting application that is accessible to everyone and everywhere. Blockchain, which is the technology behind the first Bitcoin cryptocurrency, has attracted a lot of attention globally in recent years. This paper proposes a blockchain-based voting system that removes some limitations of existing voting systems. The application is based on the Ethereum blockchain which makes the entire system secure and immutable in nature. The presented implementation is suitable for small-scale elections such as inside corporate homes, meeting rooms, and more.
Open access
Internet Traffic Analysis and Secure E-voting
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
With an expanding number of institutions participating in the global education market, verifying the legitimacy of academic achievements such as CVs and certificates has grown more difficult. Blockchain is an enabling technology that has the potential to help solve this issue. This research presents a blockchain-based achievement record system that generates a verified record of accomplishments. Using the unique characteristics afforded by Blockchain technology (public Ethereum Blockchain) and smart contracts, the proposed solution intends to make the process of certificate authentication and validation more reliable, easy, and fast. The systemâs design and structure, as well as its components and tools, are described. The system is then evaluated through a series of experiments to determine its usability, effectiveness, performance, and cost. A score of 77.1 was obtained on the System Usability Scale (SUS) test. In addition, an examination of End-User Computing Satisfaction (EUCS) revealed that participants deemed the system to be extremely useful and user-friendly. We show that this method is a major advance over older systems, being both more user-friendly and efficient, through a literature review. We also provide a thorough cost study and outline the benefits and drawbacks of various blockchain systems.
<p>In order to use the fabric blockchain to store ERC 20 tokens, each one must be issued by the owner of the asset. In the case of Fabric, the owner issues the tokens in an "unspent" state on the ledger. The owner can then open a channel on the blockchain to allow others to receive the tokens. Once the token is transferred to a recipient, it is considered "spent" and removed from the channel. When the user redeems the token, it is stored on the Hyperledger Fabric blockchain ledger. This ensures that the token will not be transferred to another owner after the end of the term.</p>\n\n<p>The infrastructure component of Hyperledger Fabric is built on the Ethereum blockchain. It has the same benefits as Ethereum, but it is not as widely adopted as Ethereum. The ERC20 standard has been around for a while, so it can be used to store ERC 20 tokens. The fabric is modular and supports customization to suit different requirements. The use of Hyperledger Fabric 2.0 as a token platform means that the asset can be stored on the blockchain and used by the users.</p>\n\n<p>Unlike Ethereum, Hyperledger is a permissioned network where participants are known and have known identities. Companies with strict data protection laws and regulations will likely be comfortable with this kind of system. However, the network doesn't offer its own token system, so if a company wants to transfer funds between accounts, it should use Ethereum. This is also the case for companies that want to implement a decentralized payment system, such as an ICO.</p>\n\n<p>Aside from its scalability and security, Hyperledger Fabric has many advantages. In the case of ERC 20 tokens, Fabric allows the developers to code "chaincodes", which are smart contracts in Hyperledger parlance. These "chaincodes" are a type of cryptographic data hash. The Fabric consensus algorithm mirrors the workflow of organizations. It also offers secure access to data and can be used to create and execute smart contracts.</p>\n\n<p>As a result of this robust security, EVM chaincode can interact with Ethereum smart contracts and Fabric. By downloading the GitHub repository, developers can customize the chaincode to map to a folder of their choice. The instructions are very detailed. Once you have the appropriate software installed, you can build the multi-container apps and test them. Additionally, you can use "Go" language for Ethereum smart contracts on Fabric.</p>\n\n<p>Tokens on Ethereum are stored on the Ethereum network, which requires a transaction fee of $400. This fee varies depending on the size of the smart contract. However, this fee can be waived when generating tokens for customers. It's also possible to purchase a service that generates tokens for customers. You'll want to take the time to learn all you can about <a href="https://cryptominnie.com/">Crypto Minnie</a> before deciding. For $20, you can get the service of CoinManufactory and create your own custom ERC 20 tokens.</p>\n\n<p>Tokenization is a significant part of blockchain networks, and it is the process of converting physical assets into digital ones. Once digital, tokens are easily exchanged, purchased, or redeemed for other digital assets. Moreover, they can be categorized as either fungible or non-fungible assets. The latter has a broader utility than the former. You can make a list of different ERC 20 tokens in a Hyperledger Fabric instance and check out the corresponding information for Hyperledger Fabric.</p>\n\n<p> Overledger is a protocol that facilitates secure access to all DLTs. It configures each DLT to accept payments and send cryptocurrency to recipients. Then it provides a secure interface for the recipients to send and receive cryptocurrency. This is a highly effective way to manage distributed assets and tokens. Ultimately, it allows an organization to secure a blockchain while enabling a wide range of applications.</p>
Today cryptocurrency, like Bitcoin, is gaining popularity in the middle people and we cannot deny its role in the global economy. Although cryptocurrency does not instead of fiat money in the near future, it will take a significant part of the market. Despite the fact that it has no special laws in many countries yet, there are already ways people can use cryptocurrency. While the crypto markets have been banned in China, Japan, on the contrary, officially allows people to pay differently services or goods via Bitcoin. Currently, there are a large number of different cryptocurrencies but this thesis describes a service that works with Ether (Eth) in its blockchain - Ethereum. In contrast Bitcoin, the Ethereum blockchain is not just a cryptocurrency support tool for it, it is a a powerful platform dedicated to a country that brings several development opportunities: new markets, loans, registrations and other resources. This makes Ethereum a good replacement by known payment methods. However, the current method of transmitting eth is still difficult for ordinary people and requires a certain technical background. This is one of the current issues for Ethereum platform. The process of creative creation is very complex moment; therefore, most people do not understand or are afraid to use it. That is slow reduces the process of eth integration in society and makes it less enjoyable to compare in standard payment systems. In addition, there is another important factor to consider - risk of loss of property. In order to create a job, the sender must know public address, 42- character long hexadecimal character unit, recipient. If any a error in any characters, money will be sent to the wrong address and can not to be downloaded. As the blockchain network has no centralized management in the system, there are no conditions that can help recover the lost money. The platform on which the service operates is called Ethereum. It can be defined as a a world-class powerful machine that uses different systems - smart contracts - using a custom blockchain. These applications work as planned and cannot checked, closed, rigged or interrupted. Created by Vitalik Buterin in 2015 an open source forum helps to streamline Blockchain (BC) technology process. integration. Therefore, it attracts interests from a variety of sources and major oneâs companies such as Microsoft and IBM. The Ethereum platform can be used in a variety of business or financial sectors. It ensures security and prevents any intrusion into the system. Companies and services based on Ethereum they can do business with other companies and services that they do not knowing without the risk of fraud. Ethereum allows you to register any type of trade for any asset without the need to use trial. This makes it easier compared to current methods of trade registration
Spatial crowdsourcing emerges as a new computing paradigm that enables mobile users to accomplish spatio- temporal tasks in order to solve human-intrinsic problems. Existing crowdsourcing systems critically use centralized servers for interacting with workers and making task assignment decisions. These systems are hence susceptible to issues such as the single point of failure and the lack of operational transparency. Prior work, therefore, turns to blockchain-based decentralized crowdsourcing systems, yet still suffers from problems of lacking efficient task assignment scheme, requiring a deposit to an untrusted system, low block generation speed, and high transaction fees. To address these issues, we design a blockchain-based decentralized framework for spatial crowdsourcing, which we call SC-EOS. Our system does not rely on any trusted servers, while providing efficient and user-customizable task assignment, low monetary cost, and fast block generation. More importantly, it frees users from making a deposit into an untrusted system. Our framework can also be extended and applied to generic crowdsourcing systems. We implemented the proposed system on the EOS blockchain. Trace-driven evaluations involving real users show that our system attains the comparable task assignment performance against a clairvoyant scheme. It also achieves 10× cost savings than an Ethereum-based implementation.
Blockchain introduces decentralized trust in peer-to-peer networks, advancing security and democratizing systems. Yet, a unified definition for decentralization remains elusive. Our Systematization of Knowledge (SoK) seeks to bridge this gap, emphasizing quantification and methodological coherence. We've formulated a taxonomy defining blockchain decentralization across five facets: consensus, network, governance, wealth, and transaction. Despite the prevalent focus on consensus decentralization, our novel index, based on Shannon entropy, provides comprehensive insights. Moreover, we delve into alternative metrics like the Gini and Nakamoto Coefficients and the Herfindahl-Hirschman Index (HHI), supplemented by an open-source Python tool on GitHub. In terms of methodology, blockchain research has often bypassed stringent scientific methods. By employing descriptive, predictive, and causal methods, our study showcases the potential of structured research in blockchain. Descriptively, we observe a trend of converging decentralization levels over time. Examining DeFi platforms reveals exchange and lending applications as more decentralized than their payment and derivatives counterparts. Predictively, there's a notable correlation between Ether's returns and transaction decentralization in Ether-backed stablecoins. Causally, Ethereum's transition to the EIP-1559 transaction fee model has a profound impact on DeFi transaction decentralization. To conclude, our work outlines directions for blockchain research, emphasizing the delicate balance among decentralization facets, fostering long-term decentralization, and the ties between decentralization, security, privacy, and efficiency. We end by spotlighting challenges in grasping blockchain decentralization intricacies.
Firms are eager to adopt new technologies, such as Artificial Intelligence (A.I.), Cloud Computing, Big Data, etc., as they witness successful business applications. As one of the disruptive technologies, Blockchain technology (BCT) has been drawing attention stemming from cryptocurrency proliferation (e.g., Bitcoin and Ethereum), for which Blockchain serves as the backbone. However, the public is haunted by the bewilderment between cryptocurrencies and BCT. Furthermore, the burgeoning of Metaverse and non-fungible tokens (NFT) has raised BCT to another notch. This study conducts a holistic literature review on BCT features, implementations, and business implications. In particular, by reviewing and analyzing 2265 up-to-date articles that reveal BCTâs applications across various fields, this Blockchain-centered study reveals the research status and delineates future research directions. It is shown that, among various characteristics of BCT, traceability is the main characteristic fueling BCTâs application in supply chain management (SCM). We further find that the BCT-related research has been extremely growing in SCM, healthcare, and government, while declining in the areas of banking and cyber security. Geographically, the top countries with BCT-related publications are China, U.S., and India. Finally, it is emphasized that BCT-related research in environmental sciences and agriculture have potential to be explored.