The emerging smart city is driving massive transformations of modern cities, facing the huge influx of sensor data from IoT devices. Edge computing distributes computing tasks to the near-edge end, which greatly enhances the service quality of IoT applications, that is, ultralow latency, large capacity, and high throughput. However, due to the constrained resource of IoT devices, currently, systems with a centralized model are vulnerable to attacks, such as DDoS from IoT botnet and central database failure, which can hardly provide high-confidence services. Recently, blockchain with a high security promise is considered to provide new approaches to enhancing the security of IoT systems. However, blockchain and IoT have obvious incompatibility, and low-capacity IoT devices can hardly be incorporated into blockchain with high computing requirements. In this paper, a blockchain-edge computing hybrid system (BEHS) is presented to make the adaptation of blockchain to edge computing and provide trustworthy IoT management services for a smart city. A novel extensible consensus protocol designed for proof-of-work, named proof-of-contribution (PoC), is proposed to regulate the data upload behaviors of nodes, especially the data upload frequency of IoT device nodes, so as to protect the system from attack about frequency. In order to secure the data privacy and authenticity, a data access control scheme is designed by integrating symmetric encryption with asymmetric encryption algorithm. We implemented a concrete BEHS on Ethereum, realized the function of PoC mechanism via smart contracts, and conducted a case study for smart city. The extensive evaluations and analyses show that the proposed PoC mechanism can effectively detect and automatically manage the behavior of nodes, and the time cost of data access control scheme is within an acceptable range.
Nakamoto's seminal work gave rise to permissionless blockchains -- as well as a wide range of proposals to mitigate their performance shortcomings. Despite substantial throughput and energy efficiency achievements, most proposals only bring modest (or marginal) gains in transaction commit latency. Consequently, commit latencies in today's permissionless blockchain landscape remain prohibitively high. This paper proposes NimbleChain, a novel algorithm that extends permissionless blockchains based on Nakamoto consensus with a fast path that delivers causal promises of commitment, or simply promises. Since promises only partially order transactions, their latency is only a small fraction of the totally-ordered commitment latency of Nakamoto consensus. Still, the weak consistency guarantees of promises are strong enough to correctly implement cryptocurrencies. To the best of our knowledge, NimbleChain is the first system to bring together fast, partially-ordered transactions with consensus-based, totally-ordered transactions in a permissionless setting. This hybrid consistency model is able to speed up cryptocurrency transactions while still supporting smart contracts, which typically have (strong) sequential consistency needs. We implement NimbleChain as an extension of Ethereum and evaluate it in a 500-node geo-distributed deployment. The results show NimbleChain can promise a cryptocurrency transactions up to an order of magnitude faster than a vanilla Ethereum implementation, with marginal overheads.
Jay Mehta, Darsh Mehta, Jainam Jain, Surekha Dholay
Abstract— The technique of following a product or a batch of things throughout the supply chain to ensure that the products that reach clients are authentic and tamper-proof is known as asset tracking. The ultimate goal of an asset monitoring system is to track products along the supply chain, verifying that they haven't been tampered with and, if they have, pinpointing where the tampering took place. Traditional tracking technologies, such as BLE (Bluetooth Low Energy Beacon), which works within a limited range, RFID, and above-mentioned systems, are expensive and centralised. So, for this project, we'll use Blockchain Technology, which is an immutable, tamper-proof, decentralised distributed ledger with security features that allows us to establish an asset tracker that can follow our product along the supply chain. Ethereum is used to implement the system. Unlike other methods, there are no hardware components or large gadgets that may be removed from the original object and attached to the copy. Keywords— Blockchain, Supply Chain, Smart Contract, Keccak-256, Ethereum,GUI
Crowdfunding is a popular method for raising funds for various projects, where a large number of individuals contribute a small amount of money to finance a particular project. It provides an opportunity for entrepreneurs, startups, and artists to seek financial support from the general public, rather than relying on traditional funding sources such as venture capitalists, banks, and angel investors. This project aims to create a decentralized crowdfunding platform using Ethereum blockchain technology. The platform allows creators to post projects with funding goals and deadlines, and investors can contribute funds to these projects. Smart contracts are used to manage the crowdfunding process, ensuring that funds are released only when milestones are met, and that investors have a say in the progress of the project. The platform is designed to be transparent, secure, and accessible to anyone with an internet connection. By using blockchain technology, the platform eliminates the need for intermediaries, reduces transaction fees, and enables global participation. This project demonstrates the potential of blockchain technology in transforming traditional funding models and enabling decentralized innovation. The platform utilizes various features of Solidity, including structs, mappings, and events, to enable the creation, management, and tracking of projects, milestones, and investments. The web interface is developed using HTML, CSS, and JavaScript, with a Node.js backend that interacts with the smart contracts using the web3.js library.
Unihedge is a decentralized platform for prediction markets with a novel approach. Using Harberger Tax (HTAX) economic policies a new type of prediction market, named HTAX prediction market, was build. HTAX prediction market derivates from Dynamic PariMutuel (DPM) type of prediction markets thus offering its users an unlimited liquidity for any preferred time horizon. It tries to solve some problems of DPM by introducing a new incentive mechanism to support early information incorporation and a protection against share readjustment for hedgers. In the paper also implementation of platform on Ethereum Virtual Machine (EVM) is presented with the usage of Decentralized Exchange (DEX) as an price discovery mechanism for prediction market resolutions.
The decentralization, redundancy, and pseudo-anonymity features have made permission-less public blockchain platforms attractive for adoption as technology platforms for cryptocurrencies. However, such adoption has enabled cybercriminals to exploit vulnerabilities in blockchain platforms and target the users through social engineering to carry out malicious activities. Most of the state-of-the-art techniques for detecting malicious actors depend on the transactional behavior of individual wallet addresses but do not analyze the money trails. We propose a heuristics-based approach that adds new features associated with money trails to analyze and find suspicious activities in cryptocurrency blockchains. Here, we focus only on the cyclic behavior and identify hidden patterns present in the temporal transactions graphs in a blockchain. We demonstrate our methods on the transaction data of the Ethereum blockchain. We find that malicious activities (such as Gambling, Phishing, and Money Laundering) have different cyclic patterns in Ethereum. We also identify two suspicious temporal cyclic path-based transfers in Ethereum. Our techniques may apply to other cryptocurrency blockchains with appropriate modifications adapted to the nature of the crypto-currency under investigation.
Lu Liu, Lili Wei, Wuqi Zhang, Ming Wen · 6 authors
Smart contracts are programs stored on blockchains to execute transactions. When input constraints or security properties are violated at runtime, the transaction being executed by a smart contract needs to be reverted to avoid undesirable consequences. On Ethereum, the most popular blockchain that supports smart contracts, developers can choose among three transaction-reverting statements (i.e., require, if…revert, and if…throw) to handle anomalous transactions. While these transaction-reverting statements are vital for preventing smart contracts from exhibiting abnormal behaviors or suffering malicious attacks, there is limited understanding of how they are used in practice. In this work, we perform the first empirical study to characterize transaction-reverting statements in Ethereum smart contracts. We measured the prevalence of these statements in 3,866 verified smart contracts from popular dapps and built a taxonomy of their purposes via manually analyzing 557 transaction-reverting statements. We also compared template contracts and their corresponding custom contracts to understand how developers customize the use of transaction-reverting statements. Finally, we analyzed the security impact of transaction-reverting statements by removing them from smart contracts and comparing the mutated contracts against the original ones. Our study led to important findings. For example, we found that transaction-reverting statements are commonly used to perform seven types of authority verifications or validity checks, and missing such statements may compromise the security of smart contracts. We also found that current smart contract security analyzers cannot effectively handle transaction-reverting statements when detecting security vulnerabilities. Our findings can shed light on further research in the broad area of smart contract quality assurance and provide practical guidance to smart contract developers on the appropriate use of transaction-reverting statements.
Mwrwan Abubakar, Zakwan Jaroucheh, Ahmed Al Dubai, Bill Buchanan
Recent years have seen an increase in medical big data, which can be attributed to a paradigm shift experienced in medical data sharing induced by the growth of medical technology and the Internet of Things. The evidence of this potential has been proved during the recent covid-19 pandemic, which was characterised by the use of medical wearable devices to help with the medical data exchange between the healthcare providers and patients in a bid to contain the pandemic. However, the use of these technologies has also raised questions and concerns about security and privacy risks. To assist in resolving this issue, this paper proposes a blockchain-based access control framework for managing access to users’ medical data. This is facilitated by using a smart contract on the blockchain, which allows for delegated access control and secure user authentication. This solution leverages blockchain technology’s inherent autonomy and immutability to solve the existing access control challenges. We have presented the solution in the form of a medical wearable sensor prototype and a mobile app that uses the Ethereum blockchain in a real data sharing control scenario. Based on the empirical results, the proposed solution has proven effective. It has the potential to facilitate reliable data exchange while also protecting sensitive health information against potential threats. When subjected to security analysis and evaluation, the system exhibits performance improvements in data privacy levels, high security and lightweight access control design compared to the current centralised access control models.
Aboul Ella Hassanien, Mohamed Torky, Essam Goda, Václav Snåšel · 5 authors
<title>Abstract</title> Blockchain technology can play a vital role in the space industry and satellite communication. This disruptive technology can build decentralized and secure protocols for processing and manipulating space transactions in the form of space digital tokens (SDTs). Tokenizing space transactions in the form of SDTs will enable various blockchain-based applications in the space industry. Moreover, blockchain protocols based on smart contracts can be utilized to authenticate many space transactions and P2P communications in a transparent, verifiable, and secure manner. This paper proposes a new blockchain-based solution for managing and securing satellite transactions using a novel concept called SDT. SDT is then used to develop a new blockchain protocol called proof of space transactions (PoST), which is then used in proposing a new blockchain-based protocol for authenticating satellite transactions. The proposed PoST protocol is implemented and simulated using the Ethereum blockchain. Five metrics are used to evaluate the protocol's performance: Ethereum GAZ, read latency, transaction latency, read throughput, and transaction throughput. The performance evaluation results proved the efficiency and reliability of PoST in managing and securing satellite transactions.
Ponlawat Weerapanpisit, Sergio Trilles, Joaquı́n Huerta, Marco Paìnho
Social Internet of Things (SIoT) is a concept that integrates the Internet of Things and human social networks. An SIoT system has to store and manage device reputation values, which are used by end devices to determine the trustworthiness of another one. This device trustworthiness can also be affected by its geographical location. In this work, we introduced an architecture that includes the geospatial context in the part concerned with reputation management. The proposed architecture is based on the cloud-fog-edge architecture and uses the fog layer as the management system. The devices in the fog layer form an Ethereum Blockchain network and store the Smart Contracts. These in turn allow the management functionalities to be carried out in a decentralised, transparent and secure way, which are the advantages of Blockchain. To enable the characteristics with a geospatial component, it is necessary to apply a geocoding technique. This work shows how geocoding techniques can be adapted to cover the main geospatial functionalities and compares two geocoding options (Geohash or S2). The results showed that it is possible to include the geospatial context in a decentralised reputation management system by using hierarchical geocoding techniques, and the experiments showed that both Geohash and S2 can offer a similar performance in the proposed architecture.
Fixing bugs is easiest by patching source code. However, source code is not always available: only 0.3% of the ~49M smart contracts that are currently deployed on Ethereum have their source code publicly available. Moreover, since contracts may call functions from other contracts, security flaws in closed-source contracts may affect open-source contracts as well. However, current state-of-the-art approaches that operate on closed-source contracts (i.e., EVM bytecode), such as EVMPatch and SmartShield, make use of purely hard-coded templates that leverage fix patching patterns. As a result, they cannot dynamically adapt to the bytecode that is being patched, which severely limits their flexibility and scalability. For instance, when patching integer overflows using hard-coded templates, a particular patch template needs to be employed as the bounds to be checked are different for each integer size. In this paper, we propose Elysium, a scalable approach towards automatic smart contract repair at the bytecode level. Elysium combines template-based and semantic-based patching by inferring context information from bytecode. Elysium is currently able to patch 7 different types of vulnerabilities in smart contracts automatically and can easily be extended with new templates and new bug-finding tools. We evaluate its effectiveness and correctness using 3 different datasets by replaying more than 500K transactions on patched contracts. We find that Elysium outperforms existing tools by patching at least 30% more contracts correctly. Finally, we also compare the overhead of Elysium in terms of deployment and transaction cost. In comparison to other tools, we find that generally Elysium minimizes the runtime cost (i.e., transaction cost) up to a factor of 1.7, for only a marginally higher deployment cost, where deployment cost is a one-time cost as compared to the runtime cost.
Nakamoto consensus underlies the security of many of the world's largest cryptocurrencies, such as Bitcoin and Ethereum. Common lore is that Nakamoto consensus only achieves consistency and liveness under a regime where the difficulty of its underlying mining puzzle is very high, negatively impacting overall throughput and latency. In this work, we study Nakamoto consensus under a wide range of puzzle difficulties, including very easy puzzles. We first analyze an adversary-free setting and show that, surprisingly, the common prefix of the blockchain grows quickly even with easy puzzles. In a setting with adversaries, we provide a small backwards-compatible change to Nakamoto consensus to achieve consistency and liveness with easy puzzles. Our insight relies on a careful choice of \emph{symmetry-breaking strategy}, which was significantly underestimated in prior work. We introduce a new method -- \emph{coalescing random walks} -- to analyzing the correctness of Nakamoto consensus under the uniformly-at-random symmetry-breaking strategy. This method is more powerful than existing analysis methods that focus on bounding the number of {\it convergence opportunities}.
Caciano dos Santos Machado, Renan R. S. dos Santos, Carla Merkle Westphall
Community networks are prone to free-riders, i.e., participants who take advantage of cooperation from others' routers but do not contribute reciprocally. In this paper, we present HARPIA, a system for credit-based incentive mechanisms for data forwarding in community networks aimed to prevent selfish behavior. HARPIA does not require a trusted third-party or tamper-resistant security modules as in other incentive mechanisms. Instead, it uses a distributed accounting scheme (DPIFA) to estimate the balance of data forwarding contribution and consumption of each network router and settle correspondent cryptocurrency debts on an Ethereum smart contract. On-chain settlement transactions are performed every HARPIA cycle (e.g., daily, weekly, monthly) and must be validated by at least m-of-n network routers using a multi-signature scheme (MuSig). We also realized a performance evaluation, security threat assessment, and cryptocurrency costs estimation. Results show that our proposal is suitable for community networks with up to 64 infrastructure routers under specific m-of-n MuSig thresholds.
Ikechi Saviour Igboanusi, Kevin Putra Dirgantoro, Jae‐Min Lee, Dong‐Seong Kim
This article proposes an electronic payment architecture named Pure Wallet (PW), which extends the concept of Blockchain cryptocurrency for offline transactions. The process is divided into three steps. The first step requires the use of Internet connection, to convert cryptocurrency into a token at the token manager. The token manager initiates a transaction that requires the information in the token to complete. Then offline transactions step is performed between electronic devices like mobile phones through a secure Near Field Communication (NFC) using the token in senders device. The financial value in the form of a token is encrypted by the sender and sent to the receiver’s device via NFC. In the third step, the receiver converts the received token into cryptocurrency in the presence of Internet connection by sending the information required to complete the transaction to the token manager. The goal is to propose an electronic payment architecture utilizing Blockchain, which will enable financial transactions without instant connection to the Internet. The Blockchain implementation in this work utilizes smart contract in Ethereum Blockchain. The result shows a successful transfer of value without instant Internet connection. The open issues related to Blockchain in offline transactions are listed for further research works.
A smart Ponzi scheme is a new form of economic crime that uses Ethereum smart contract account and cryptocurrency to implement Ponzi scheme. The smart Ponzi scheme has harmed the interests of many investors, but researches on smart Ponzi scheme detection is still very limited. The existing smart Ponzi scheme detection methods have the problems of requiring many human resources in feature engineering and poor model portability. To solve these problems, we propose a data-driven smart Ponzi scheme detection system in this paper. The system uses dynamic graph embedding technology to automatically learn the representation of an account based on multi-source and multi-modal data related to account transactions. Compared with traditional methods, the proposed system requires very limited human-computer interaction. To the best of our knowledge, this is the first work to implement smart Ponzi scheme detection through dynamic graph embedding. Experimental results show that this method is significantly better than the existing smart Ponzi scheme detection methods.
M. Satheesh Kumar, S. Vimal, N. Z. Jhanjhi, Shanmuga Sundar Dhanabalan · 5 authors
With the prevalence of Aerospace Technologies, the regulations of cybersecurity are becoming smarter, assured, and long-lasting. Modern communication network technologies have enormous growth in the cyber threats and masquerading attacks to steal data. Hence concepts and mechanisms are built and made into regulations for a safer environment. Unmanned aerial vehicles (UAVs), often known as drones, are becoming increasingly common, posing new problems in areas such as monitoring, agriculture, weather prediction, surveillance and other fields. This includes a large number of devices that, owing to a lack of energy or a system shutdown, might occasionally send incorrect signals and must be monitored autonomously by drones in remote regions. In this paper, we propose a energy intensive blockchain-based platform for controlling drone operations while ensuring trust and security for all parties involved. The goal of this paper is to explore the extent of Unmanned Aerial Vehicle (UAV) vulnerability to deceptive (Global Navigation Satellite System) GNSS signals by establishing the necessary conditions for UAV via GPS (Global Positioning System) spoofing. The existing algorithms used to mitigate spoofing attacks have unbounded long-term errors, which increase in time during its performance. An innovative idea is necessitating to eliminate those errors, thereby in the proposed work, Ethereum Blockchain has been implemented to create a blockchain network to mitigate the spoofing attacks. Blockchains are incredibly popular nowadays and is the basic technology for cryptocurrencies. Blockchain technology greatly impacts the applications in UAVs. The proposed methodology uses the network that has to be registered in the aerospace components through the ledger associated with relevant data communication in the Blockchain. When an intruder gets acquired with the data in the network with a single block, it cannot affect the entire network due to the data integrity in the ledgers that has been cryptographically assigned. The blockchain network intermittently verifies the geolocation data so that any outlying data would be detected and eliminated quickly. The data that has been verified is made available for the view of aviation and spacecraft operations through the distributed network. The proposed methodology outperforms the existing methods in intense drift error and, in the case of confidentiality and integrity, it has very low risk when compared to existing methods.
The use of digital health records, stricter health laws and the growing need for health records exchange points towards the need for an efficient security and privacy preserving mechanism. For Health Insurance management systems, multiple entities exchange health information which is used for decision making. Since multiple authoritative entities are involved, a secure and efficient information sharing protocol is required as extremely sensitive health information is exchanged among the entities. Hence this paper aims to put forward a novel a decentralized authentication system based on Blockchain known as Insurance Claim Blockchain (ICBChain) system. The proposed system ensures privacy of patients, provides secure information exchange and authentication of entities. An implementation of the proposed system is provided using Ethereum Blockchain. The security and performance analysis of the system shows its potential to satisfy Healthcare security requirements and its efficiency respectively
In order to have transactions executed and recorded on blockchains such as the Ethereum Mainnet, fees expressed in crypto-currency units of the blockchain must be paid. One can buy crypto-currency called Ether of the Ethereum blockchain from exchanges and pay for the transaction fees. In the case of test networks (such as Rinkeby) or scientific research blockchains (such as Bloxberg), free crypto-currency, Ether, is distributed to users via faucets. Since transaction slots on the blocks, storage and smart contract executions are consuming blockchain resources, Ethers are distributed by fixed small amounts to users. Users may have different amount of Ether requirements; some small amounts and some large amounts during different times. As a result, rather than allowing the user to get a fixed small amount of Ether, a more general distribution mechanism that allows a user to demand and claim arbitrary amounts of Ether, while satisfying fairness among users, is needed. For this end, Max-min Fairness based schemes have been used in centralized settings. Our work contributes a Max-min Fairness based algorithm and its Solidity smart contract implementation that requires low transaction costs independent of the number of users. This is important on the Ethereum blockchain, since a smart contract execution with transaction costs depending on the number of users would mean block gas limit exhaustion problem will eventually be met, making the smart contract ineffective. We report tests which confirm that the low transaction cost aims have been achieved by our algorithm.
Abstract Classifying test executions automatically as pass or fail remains a key challenge in software testing and is referred to as the test oracle problem . It is being attempted to solve this problem with supervised learning over test execution traces. A programme is instrumented to gather execution traces as sequences of method invocations. A small fraction of the programme's execution traces is labelled with pass or fail verdicts. Execution traces are then embedded as fixed length vectors and a neural network (NN) component that uses the line‐by‐line information to classify traces as pass or fail is designed. The classification accuracy of this approach is evaluated using subject programs from different application domains—1. Module from Ethereum Blockchain, 2. Module from PyTorch deep learning framework, 3. Microsoft SEAL encryption library components, 4. Sed stream editor, 5. Nine network protocols from Linux packet identifier, L7‐Filter and 6. Utilities library, commons‐lang for Java. For all subject programs, it was found that test execution classification had high precision, recall and specificity, averaging to 93%, 94% and 96%, respectively, while only training with an average 14% of the total traces. Experiments show that the proposed NN‐based approach is promising in classifying test executions from different application domains.
The cryptocurrency market is a market that attracts researchers and investors because it is open every day. This can be seen by the anomalies that occur in the cryptocurrency market. This research uses cryptocurrencies with the largest market cap in 2020, namely Bitcoin, Ethereum, Tether, XRP, and Bitcoin cash as research objects. The data in this study uses daily returns for testing the day of the week effect and daily volatility on the cryptocurrencies under study. This study uses GARCH (1,1) to determine the day of the week effect and daily volatility in the cryptocurrency under study. The results of this study indicate that there is a day of the week effect and daily volatility in the cryptocurrency under study, and it does not move freely. This causes the cryptocurrency market to become an inefficient market. The patterns that occur can be exploited by investors as well as other research on the cryptocurrency under study. Investors can avoid days that have high volatility for example in Bitcoin which experiences high volatility on Fridays and Saturdays because it has a high risk as well. Investors are advised to be able to trade on Thursday for high returns and less risk.
Jinlei Sun, Song Huang, Changyou Zheng, Tingyong Wang · 6 authors
Integer overflow is a common vulnerability in Ethereum Smart Contracts (ESCs) and often causes huge economic losses. Smart contracts cannot be changed once it is deployed on the blockchain and thus demand further testing. Mutation testing is a fault-based testing method that can effectively improve the sufficiency of a test for smart contracts. However, existing methods cannot efficiently perform mutation testing specifically for integer overflow in ESCs. Therefore, by analyzing integer overflow in ESCs, we propose five special mutation operators to address such vulnerability in terms of detecting sufficiency in ESC testing. An empirical study on 40 open-source ESCs is conducted to evaluate the effectiveness of the proposed mutation operators. Results show that: (1) our proposed mutation operators can reproduce all 179 integer overflow vulnerabilities in 40 smart contracts, and the generated mutants have high compilation pass rate and integer overflow vulnerability generation rate; moreover, (2) the generated mutants can find the shortcomings of existing testing methods for integer overflow vulnerability, thereby providing effective support to improve the sufficiency of the test.
Emerson de Brito Souza, Elisângela Carneiro, Antonio Coutinho
Este artigo propõe um sistema para a geração e validação de diplomas e certificados onde os documentos sejam confiáveis e facilmente verificáveis. Para isso foi utilizada a rede blockchain pública da Ethereum aliada com uma rede de arquivos distribuída usando o protocolo InterPlanetary File System e ferramentas de código aberto. O modelo mostra que a realização do sistema é viável, englobando propriedades de sistemas off-chain e on-chain para a arquitetura proposta.