Conditional thank-you gifts are one of the most widely used incentives for charitable giving. Past studies explored non-monetary thank-you gifts (e.g., mugs and shirts) and monetary thank-you gifts (e.g., rebates that return some of the donations to the giver). Following the rapid growth of blockchain technology, a novel form of thank-you gifts emerged: the crypto rewards. Through two studies, we analyze crypto thank-you gifts to shed light on fundraising designs in the digital world. In Study I, we examine the Ukrainian government's crypto fundraising plea that accepts donations in both Ethereum and Bitcoin. We find that Ethereum is substantially more effective in enticing giving than Bitcoin, as the hourly donation count increased 706.07% more for Ethereum than for Bitcoin when crypto rewards are present. This is likely because the crypto rewards are more likely to be issued on Ethereum than Bitcoin. However, the decrease in contribution sizes is also more substantial in Ethereum than in Bitcoin in response to the crypto rewards. In Study II, we conducted a laboratory experiment following a dictator game design to investigate the impact of crypto rewards in a more general scenario, with the crypto rewards specified as non-fungible tokens (NFTs). The crypto rewards in Study II carry no monetary value but only serve to recognize donors symbolically. As such, the NFT thank-you gifts did not effectively induce people to donate; a traditional 1:1 donation matching strictly outperforms both the condition without thank-you gifts and the condition with NFT thank-you gifts. Nevertheless, the NFT thank-you gifts effectively increased the contribution sizes, conditional on the choice to give, when the NFT's graphic design primes donor identity and encompasses the charity recipient.
WebAssembly (Wasm) smart contracts have shown growing popularity across blockchains (e.g., EOSIO) recently. Similar to Ethereum smart contracts, Wasm smart contracts suffer from various attacks exploiting their vulnerabilities. Even worse, few developers released the source code of their Wasm smart contracts for security review, raising the bar for uncovering vulnerable contracts. Although a few approaches have been proposed to detect vulnerable Wasm smart contracts, they have several major limitations, e.g., low code coverage, low accuracy and lack of scalability, unable to produce exploit payloads, etc. To fill the gap, in this paper, we design and develop WASAI, a new concolic fuzzer for uncovering vulnerabilities in Wasm smart contract after tackling several challenging issues. We conduct extensive experiments to evaluate WASAI, and the results show that it outperforms the state-of-the-art methods. For example, it achieves 2x code coverage than the baselines and surpasses them in detection accuracy, with an F1-measure of 99.2%. Moreover, WASAI can handle complicated contracts (e.g., contracts with obfuscation and sophisticated verification). Applying WASAI to 991 deployed smart contracts in the wild, we find that over 70% of smart contracts are vulnerable. By the time of this study, over 300 vulnerable contracts have not been patched and are still operating on the EOSIO Mainnet. One fake EOS vulnerability reported to the EOSIO ecosystem was recently assigned a CVE identifier (CVE-2022-27134).
Alan Rodrigues, Allysson Allex Araújo, Matheus Paixão, Pamella Soares
Presencia-se uma adesão de projetos de Contratos Inteligentes (CIs) ao desenvolvimento open source. Ademais, reconhece-se que o desenvolvimento de CIs lida com novas restrições as quais motivam novos questionamentos sobre a dinâmica de colaboração entre desenvolvedores e para com a comunidade. Enquadrando-se a partir de uma pesquisa exploratória-descritiva, o presente artigo objetiva discutir resultados preliminares sobre elementos colaborativos quanto ao desenvolvimento open source de CIs, em específico: i) a relação entre commits e colaboradores, e ii) quanto ao report e resolução de issues.
The main contribution of this research is to investigate whether an Artificial Neural Network is an option to predict Ethereum cryptocurrency close price on a time constrained scenario. The ANN training time and time lagged data availability are considered as constraints on finding the fastest and the most accurate regression model using ARIMA results as a baseline. As part of the study, hourly aggregated data is processed to generate a step-ahead forecast and then processing time is compared for each architecture. Previous work related to cryptocurrency forecasting usually focus the analysis only on accuracy, and use coarser data granularity. Results have shown that convolutional neural networks over performed other architectures for accuracy and time objectives.
Blockchain is a modern technology that has revolutionized the way society interacts and trades. It could be defined as a chain of blocks that stores information with digital signatures in a distributed and decentralized network. This technique was first adopted for the creation of digital cryptocurrencies, such as Bitcoin and Ethereum. However, research and industrial studies have recently focused on the opportunities that blockchain provides in various other application domains to take advantage of the main features of this technology, such as: decentralization, persistency, anonymity, and auditability. This paper reviews the use of blockchain in several interesting fields, namely: finance, healthcare, information systems, wireless networks, Internet of Things, smart grids, governmental services, and military/defense. In addition, our paper identifies the challenges to overcome, to guarantee better use of this technology.
Open access
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
Thanks to cryptocurrencies, blockchain technology has recently become the focus of interest of both scientists and the public. The paper presents the principles on which blockchain is based and analyzes the possibilities of the application of blockchain technology in more detail. In a part of the analysis, some of the most common cryptocurrencies were considered, such as Bitcoin, Ethereum, USD Coin, Ripple, and ADA. Blockchains' applicability in supply chains, finance, real estate, health care, voting, and smart cities the authors discussed in the chapter about the application of blockchain technology. A separate chapter discusses the limitations of blockchain technology. Based on the analysis, at the end of the paper, the authors conclude that blockchain technology has great potential in automating and optimizing business processes and protecting the information and privacy of users. Given the demonstrated interest of companies in blockchain technology, investments, and demand for staff who understand it and can create applications, the authors concluded that the time of blockchain is yet to come.
Decentralized Applications (DApps) have seen widespread use in the recent past driving the world towards a new decentralized version of the web known as Web3.0. DApp-supported blockchains like Ethereum have largely been responsible for this drive supporting the largest eco-system of DApps. Although the low performance provided by Ethereum has been a major impediment to realizing a decentralized web, several high-performance blockchains have been introduced recently to bridge this gap. Most of these blockchains rely on consensus optimizations. Only a few enhance other parts of the blockchain protocol that involves transaction management: the validation of transactions, broadcast of transactions, encapsulation and dissemination of blocks with transactions, re-validation and execution of transactions in blocks, storage of blocks, and confirmation of transaction commits to senders upon request. In this paper, we enhance transaction management by introducing a novel transaction validation reduction and a per sub-block processing to optimize the block storage. We empirically show the performance improvements gained by our enhanced transaction management in the Smart Red Belly Blockchain (SRBB) VM we develop. Finally, we integrate our SRBB VM to an already optimized consensus from a known blockchain to develop the Smart Red Belly Blockchain. Our results show that SRBB achieves a peak throughput of 4000 TPS and an average throughput of 2000 TPS on 200 nodes spread across 5 continents. SRBB outperforms 6 other blockchains when running the exchange DApp featuring a real workload trace taken from Nasdaq.
Recently, unmanned aerial vehicles (UAVs) are deployed in Novel Coronavirus Disease-2019 (COVID-19) vaccine distribution process. To address issues of fake vaccine distribution, real-time massive UAV monitoring and control at nodal centers (NCs), the authors propose SanJeeVni, a blockchain (BC)-assisted UAV vaccine distribution at the backdrop of sixth-generation (6G) enhanced ultra-reliable low latency communication (6G-eRLLC) communication. The scheme considers user registration, vaccine request, and distribution through a public Solana BC setup, which assures a scalable transaction rate. Based on vaccine requests at production setups, UAV swarms are triggered with vaccine delivery to NCs. An intelligent edge offloading scheme is proposed to support UAV coordinates and routing path setups. The scheme is compared against fifth-generation (5G) uRLLC communication. In the simulation, we achieve and 86% improvement in service latency, 12.2% energy reduction of UAV with 76.25% more UAV coverage in 6G-eRLLC, and a significant improvement of [Formula: see text]% in storage cost against the Ethereum network, which indicates the scheme efficacy in practical setups.
Mohammad Amin Moradi, Navid Niazkar, Alireza Dehmardan
Today the emergence of many technologies has transformed the financial and commercial sectors. Blockchain is considered one of the emerging technologies in various industries. Blockchain financing allows investors to choose projects they trust and participate in without the need for third-party intermediaries. According to the main features of blockchain, using it in crowdfunding makes this process more reliable. This study presents a model based on a smart contract on the Ethereum blockchain network and integrates the (ICO) and (IPO) models. As a result, the shareholders can track the project's progress via its corresponding Digital Twins in its respective Metaverse.
Victor Youdom Kemmoe, Yongseok Kwon, Rasheed Hussain, Sunghyun Cho · 5 authors
Group Key Exchange (GKE) is an important tool to develop secure multi-user applications such as group text messages, ad-hoc networks, and so on. Most of the currently deployed GKE schemes are synchronous, i.e., they require all the participants to be online during their execution. However, with more battery-powered devices being used in such applications, the synchronicity requirement is challenging to fulfill. To fill the gaps, asynchronous GKE schemes have been introduced in the literature. Nevertheless, the currently available asynchronous and synchronous GKE schemes rely on Trusted Third Parties (TTPs) for key establishment and management. To this end, reliance on TTPs is a serious shortcoming since TTPs are well known to be the single point of failure. Furthermore, the existing GKE schemes require participants to perform all computations, which can degrade the performance of resource-constrained devices such as Internet of Things (IoT) devices. To solve these problems, in this paper, we propose an asynchronous GKE scheme that uses blockchain and smart contracts to store the security keys-related material and reduce the computational load of the participants. Furthermore, our proposed scheme provides Perfect Forward Secrecy (PFS) and Post-Compromised Security (PCS). Our implementation on Ethereum shows that the proposed scheme can scale to more than 100 participants when combined with a distributed storage system.
Financial supply chain (Supply Chain Finance/SCF) is a hot topic in supply chain management research (Supply Chain Management). SCF's goal is to diversify funding sources from companies with limited capital and be able to improve financial efficiency throughout the company's supply chain network. SCF has become a source of short-term funding for thousands of micro, small and medium enterprises (MSMEs). The current research on SCF still uses a conventional financial framework, and no SCF research uses an Islamic financial framework. This study aims to develop an SCF framework and system based on Islamic sharia principles in the form of a sharia crowdfunding platform using blockchain technology and smart contracts. The system design produced by this research uses smart contracts that are run using the Ethereum protocol to prevent fraud/embezzlement and improve the security system on the planned platform, according to blockchain characteristics, which are very difficult to take over.
Permissionless or public Distributed Ledger Technologies (DLTs) provide full decentralization and transparency. The performance evaluation of permissionless Distributed Ledger Technologies is difficult due to their dynamic nature. This paper focuses on the performance evaluation of permissionless Ethereum DLT. Public test networks highly resemble the main network and capture the dynamic nature of permissionless DLTs. The paper proposes the BloodTrace application to trace the donated blood from the donor to the patient. The performance is evaluated by deploying the BloodTrace smart contract on the public test network Ropsten. The data collection for the calculation of the performance parameters can be performed in two ways: i) RPC based method ii) Log-based method. RPC based method involves polling the blockchain for each transaction data. The log-based method involves the collection of logs and fewer RPC calls to the Blockchain. The probabilistic nature of transaction confirmation is also taken into consideration while calculating the Latency (Finality) by analysing the effect of block confirmations on the latency. The evaluation results are then compared with the results obtained by the Hyperledger Caliper Benchmarking tool as it is using RPC based approach for calculation of performance parameters.
Blockchain is a new technology which is basically used for store and verified transactions of cryptocurrency like Bitcoin, Ethereum etc. It is a digital, distributed, decentralized and immutable ledger. Transactions in Blockchain always store after verified by multiple validators in peer-to-peer network by using consensus algorithms like Proof of Work (PoW), Proof of Stake (PoS) etc. In blockchain there is no third party involved or managed the transactions. This paper elaborates the basics of Blockchain, its digital transactions in multiple areas like Internet of Things, Education, Manufacturing and financial services, characteristics and limitations of consensus algorithms, gave technical guidance for a suitable consensus algorithms and further areas of research.
U ovom radu opisani su osnovni principi distribuiranih sistema, razvoj blokčejn tehnologija kroz tri faze, pojam Ethereum platforme, kao i arhitektura klijenata za pristup Ethereum mreži. Predstavljeno je rešenje u vidu implementacije promene na Ethereum klijentu kao posledice zahteva Ethereum zajednice za ažuriranje Ethereum platforme
Nowadays, the vast majority of Internet services used to distribute hypermedia content follow a centralized model, which is highly dependent on servers and raises several quality and security concerns. Among other issues, this centralized model creates single points of failure, requires trust on providers to avoid censorship and personal data misuse, and results in a scenario where digital content tends to disappear or be inaccessible over time, for example, when a content creator stops maintaining a site or when the content is moved to another location. To improve this, it is necessary to replicate data and follow more distributed models. Nevertheless, current platforms to distribute content in this way, either do not offer an effective mechanism to maintain the privacy of their users or they offer full-anonymity, which contributes to the dissemination of content that goes beyond the law and moral standards of many users. This paper proposes a novel distributed architecture that enables hypermedia resource distribution ensuring censorship resistance and conditional k-anonymity. In the proposed system, users form groups to share hypermedia content where the anonymity of the publisher is preserved only if the publication follows a set of rules defined by the group. To this end, the proposed system uses threshold discernible ring signatures to enable conditional k-anonymity, the Ethereum blockchain platform to manage groups and user identities, and the InterPlanetary File System to store and share hypermedia resources in a distributed way. This document provides the design for the proposed architecture and protocols, it evaluates system risks and its security properties, and it discusses the proposal in general terms.
By the development and advancement of blockchain technique, Internet of Things (IoT) proliferation driven devices and the application of blockchain-enabled IoT alter the view and operating infrastructure of the smart networks. The blockchain is responsible for supporting decentralized systems and offers secured means of authentication, management, and access to IoT system thereby deploying smart contracts offered by Ethereum. The increasing demand and the blockchain expansion generate huge volume of sensitive data. The growing demand and expansion of blockchain-IoT systems is generating large volume of sensitive data. Furthermore, distributed denial-of-service (DDoS) attacks are regarded as the most promising threats for smart contracts in the blockchain-based systems. Therefore, there is a need to detect and classify the attack type and the data should be stored in server more securely with the use of blockchain and data aggregation method. For this purpose, this presented technique aims at introducing decentralized consensus blockchain and Interplanetary file system (IPFS) based data aggregation for effective classification and data storage. The attack is detected using meta-hyperparameter random forest (MHP-RF) classifier. Once the attack is detected, the transaction information is stored in server securely by means of smart contract-based blockchain system. The transaction handling stage classifies the transaction type as normal or abnormal one which then followed by execution of business logic by smart contract thereby appending the transaction of blockchain in the network cloud. The consensus blockchain technique is employed with the use of PoW-enabled scheme integrated with Elgamal-based data aggregation. Therefore, the system security is improved and the intrusion is prevented greatly. The performance analysis of the system is analyzed in terms of accuracy, precision, recall, F-score, Encryption time, decryption time, execution time, and space complexity. The attained outcomes are compared with traditional approaches to prove the effectiveness of proposed strategy. The proposed system is said to be effective in time consumption, classifier performance, and in overcoming space complexity issues.
Over the past years, cryptocurrencies have drawn substantial attention from the media while attracting many investors. Since then, cryptocurrency prices have experienced high fluctuations. In this paper, we forecast the high-frequency 1 min volatility of four widely traded cryptocurrencies, i.e., Bitcoin, Ethereum, Litecoin, and Ripple, by modeling volatility to select the best model. We propose various generalized autoregressive conditional heteroscedasticity (GARCH) family models, including an sGARCH(1,1), GJR-GARCH(1,1), TGARCH(1,1), EGARCH(1,1), which we compare to a multivariate DCC-GARCH(1,1) model to forecast the intraday price volatility. We evaluate the results under the MSE and MAE loss functions. Statistical analyses demonstrate that the univariate GJR-GARCH model (1,1) shows a superior predictive accuracy at all horizons, followed closely by the TGARCH(1,1), which are the best models for modeling the volatility process on out-of-sample data and have more accurately indicated the asymmetric incidence of shocks in the cryptocurrency market. The study determines evidence of bidirectional shock transmission effects between the cryptocurrency pairs. Hence, the multivariate DCC-GARCH model can identify the cryptocurrency market’s cross-market volatility shocks and volatility transmissions. In addition, we introduce a comparison of the models using the improvement rate (IR) metric for comparing models. As a result, we compare the different forecasting models to the chosen benchmarking model to confirm the improvement trends for the model’s predictions.
U ovom radu predstavljeno je potencijalno rešenje za decentralizovanu aplikaciju za sportsku kladionicu u okviru Ethereum blockchain mreže. Objašnjenje su teorijske osnove i navedeni izazovi koji se susreću u ovom domenu. Opisane su terminologije vezane za ovu decentralizovanu aplikaciju kao što su blockchain tehnologija, Ethereum blockchain, koncept pametnih ugovora, Oracle entiteti i Solidity jezik. Na kraju je prikazan model i opis implementacije sistema, kao i završna zaključena zapažanja.
Emerging growth in technology has rapidly changed our homes and cities. Present homes and cities will be upgraded to smart homes and smart cities in the near future. Various solutions used to build the smart-city network demand a scalable and decentralized solution. This study proposes a blockchain-empowered decentralized and scalable solution for a sustainable smart-city network. The Internet of Things (IoT), fog nodes, permissioned trust chain, smart contract, blockchain, and InterPlanetary file system (IPFS) are deployed to construct a scalable and decentralized solution for a sustainable smart city. Three main public sector departments, i.e., electricity, water supply, and health care, are studied over the proposed solution. The proposed solution is implemented over constrained application protocol (CoAP) and Ethereum blockchain. The performance of the proposed model is evaluated for 1500 devices and over 10,000 records. A total 77.44% improvement is registered during performance evaluation over a scalable environment. The performance evaluation of each case study and collaborative performance evaluation concludes the improvised performance of the proposed solution for scalable and distributed applications. Better performance, scalability, and the distributed nature of the presented model make it suitable for the sustainable smart-city network.
Voting stands as a cornerstone of democracy in any nation, empowering citizens to select future leaders and express their views within their communities. It fosters an understanding of civic duty and citizenship significance. Online voting systems, digital platforms designed to conduct elections securely, streamline the voting process by eliminating traditional paper ballots and in-person gatherings. These systems safeguard the integrity of each vote by preventing multiple submissions. Contrasting paper-based methods, electronic voting, or e-voting, offers inherent advantages such as heightened efficiency and reduced errors. Such systems promote broader participation by enabling individuals to vote from any location with internet access. Blockchain technology, an emerging decentralized innovation with robust cryptographic underpinnings, holds promise for enhancing various industries. Integrating e-voting with blockchain could address existing e-voting concerns. Here, we propose a blockchain-based voting system to curb fraud and enhance the simplicity, security, and efficiency of the voting process. Keywords: Blockchain, Ethereum, Smart-contracts, Online-voting, Privacy, Trust, Security
The prosperity of decentralized finance motivates many investors to profit via trading their crypto assets on decentralized applications (DApps for short) of the Ethereum ecosystem. Apart from Ether (the native cryptocurrency of Ethereum), many ERC20 (a widely used token standard on Ethereum) tokens obtain vast market value in the ecosystem. Specifically, the approval mechanism is used to delegate the privilege of spending users' tokens to DApps. By doing so, the DApps can transfer these tokens to arbitrary receivers on behalf of the users. To increase the usability, unlimited approval is commonly adopted by DApps to reduce the required interaction between them and their users. However, as shown in existing security incidents, this mechanism can be abused to steal users' tokens. In this paper, we present the first systematic study to quantify the risk of unlimited approval of ERC20 tokens on Ethereum. Specifically, by evaluating existing transactions up to 31st July 2021, we find that unlimited approval is prevalent (60%, 15.2M/25.4M) in the ecosystem, and 22% of users have a high risk of their approved tokens for stealing. After that, we investigate the security issues that are involved in interacting with the UIs of 22 representative DApps and 9 famous wallets to prepare the approval transactions. The result reveals the worrisome fact that all DApps request unlimited approval from the front-end users and only 10% (3/31) of UIs provide explanatory information for the approval mechanism. Meanwhile, only 16% (5/31) of UIs allow users to modify their approval amounts. Finally, we take a further step to characterize the user behavior into five modes and formalize the good practice, i.e., on-demand approval and timely spending, towards securely spending approved tokens. However, the evaluation result suggests that only 0.2% of users follow the good practice to mitigate the risk.
Sérgio Guerreiro, João F. Ferreira, Tiago A. H. Fonseca, Miguel Correia
This paper reports the design, implementation, and experimental phases of the EU H2020 QualiChain pilot “Staffing the Public Sector—The Case of Portugal”. The overall purpose of this pilot is to ensure the authenticity and integrity of the diplomas for all involved stakeholders and therefore to contribute to solving the diploma counterfeiting and/or falsification that is a great threat to the recruitment of qualified personnel. The main innovative aspect of this solution is the integration that is offered between an Academic Management System (the Fenix.edu platform) and a Blockchain (Ethereum) to automatically deploy diplomas. This solution helps the involved stakeholders trust the diplomas provided. The case study involves four different stakeholders and studies, specifically, the increase in their satisfaction in terms of diploma control, diploma veracity, and diploma credibility. The developed system was tested with external participants who were asked to follow a set of guidelines and complete a survey to assess their perceptions. All system interactions were recorded, and the data were analyzed. The results indicated that the participants successfully executed the guidelines and that a perception increase toward diploma control, veracity, and credibility was identified.
Smart contracts provide the means to stipulate rules of interaction between mutually distrustful organizations. They encode contractual agreements on the basis of source code, which else need to be contractualized in natural language. While the mediation of contractual agreements via smart contracts is seamless in theory, it requires that the conditions of an interaction are accurately made available in the blockchain. Time is a prominent such condition. In the paper at hand, we empirically measure the consistency of a smart contract to yield equal results on the basis of the time of an interaction and its potentially inaccurate representation in the blockchain. We propose a novel metric called execution accuracy to measure this consistency. We specifically measure the execution accuracy of a time intervalconstrained smart contract that executes distinct logic within and without some constraint interval. We run experiments for the local Ganache and Quorum and the public Görli and Rinkeby Ethereum blockchains. Our experiments confirm our intuition that execution accuracy decreases near interval bounds. The novelty of our proposed metric resides in its capacity to quantify this decrease. We demonstrate how time constraints can be effectively stipulated on the basis of execution accuracy measurements.