Sebastian Göndör, Hakan Yıldız, Martin Westerkamp, Axel Kuupper
Decentralized services and applications provide a multitude of advantages for their users, such as improved privacy, control, and independence from third parties. Anyhow, decentralization comes at the cost of certain disadvantages, such as increased application complexity or communication overhead. This aggravates the development and deployment of decentralized services and applications. In this paper we present Blade, a software platform that aims to ease the effort of development, deployment, and administration of decentralized services by implementing reusable solutions for recurring challenges developers are facing when designing decentralized service architectures. This includes functionality for e.g. identity management, access control, request handling, verification of authenticity and integrity, discovery, or routing. Blade implements all this functionality in a Blade server instance, which can be deployed on a lightweight device, such as a NAS, Raspberry Pi, or router at home. This allows users without expert knowledge to run a Blade instance with already existing hardware with little overhead. Blade supports polyglot Blade modules that implement extended functionality, such as interfaces, frontends, and business logic of decentralized applications, e.g. a decentralized instant messaging service or an online social network. Based on the Oracle GraalVM, Blade modules can be implemented in a variety of programming languages and utilize the functionality provided by the Blade server instance. Blade modules are published in a Ethereum-based decentralized marketplace from where they can be installed directly via the Blade instances...
Blockchain received a vast amount of attention in recent years and is still growing. The second generation of blockchain, such as Ethereum, allows execution of almost any program in Ethereum Virtual Machine (EVM), making it a global protocol for distributed applications. The code deployment and each operation performed in EVM cost the network fee called gas, which price varies and can be significant. That is why code optimization and well-chosen algorithms are crucial in programming on the blockchain. This paper evaluates the gas usage of several exact pattern matching algorithms on the Ethereum Virtual Machine. We also propose an efficient implementation of the algorithms in the Solidity/YUL language. We evaluate the gas fees of all the algorithms for different parameters (such as pattern length, alphabet size, and text size). We show a significant gas fee and execution time reduction with up to 22-fold lower gas usage and 55-fold speed-up comparing to StringUtils (a popular Solidity string library).
Agriculture in developing countries faces numerous challenges such as price fluctuation and non-uniformity, presence of untrusted middlemen in the supply chain, crop wastage due to inadequate storage facilities or long commutes, and lack of proper monitoring. Blockchain technology has emerged as a promising approach to solve these challenges. Even though a number of solutions are recently proposed in the literature, they lack in several aspects: (1) lack of proper regulatory interface, (2) absence of proper agricultural supply chain, (3) absence of adequate storage facilities, (4) absence of a fair payment system, (5) poor monitoring and auditing system, (6) non-inclusion of government policies, and (7) missing experimental validation. This paper presents a novel blockchain-based smart agriculture system that overcomes the above-mentioned issues. In particular, our solution covers product traceability in the supply chain, elimination of counterfeit products, easily accessible cold storage facilities, fair payment procedure between buyers and sellers, a transparent process of distributing government financial benefits to farmers, and overall government monitoring. We present a prototype implementation of our proposed system using Ethereum. The backend smart contracts are developed using Solidity programming language, whereas the frontend is developed using ReactJS. The experimental evaluation using Hyperledger Caliper benchmark tool shows an encouraging result, demonstrating the system performance in terms of execution gas costs, CPU utilization, average latency, and transaction throughput.
Hanaa Abbas, Maurantonio Caprolu, Roberto Di Pietro
Polkadot is a network protocol launched in 2020 with the ambition of unlocking the full potential of blockchain technologies. Its novel multi-chain protocol allows arbitrary data to be transferred across heterogeneous blockchains, enabling the implementation of a wide range of novel use cases. The Polkadot architecture is based on the principles of sharding, which promises to solve scalability and interoperability shortcomings that encumber many existing blockchain-based systems. Lured by these impressive features, investors immediately appreciated the Polkadot project, which is now firmly ranked among the top 10 cryptocurrencies by capitalization (around 20 Billions USD). However, Polkadot has not received the same level of attention from academia that other proposals in the crypto domain have received so far, like Bitcoin, Ethereum, and Algorand, to cite a few. Polkadot architecture is described and discussed only in the grey literature, and very little is known about its internals. In this paper, we provide the first systematic study on the Polkadot environment, detailing its protocols, governance, and economic model. Then, we identify several limitations -- supported by an empirical analysis of its ledger -- that could severely affect the scalability and overall security of the network. Finally, based on our analysis, we provide future directions to inspire researchers to investigate further the Polkadot ecosystem and its pitfalls in terms of performance, security, and network aspects.
Digital currencies such as Ethereum and XRP allow for all transactions to be carried out online. To emphasize the decentralized nature of fiat currency, we can refer, for example, to the fact that all virtual currency users may access services without third-party involvement. Cryptocurrency price swings are non-stationary and highly erratic, similarly to the price changes of conventional stocks. Owing to the appeal of cryptocurrencies, both investors and researchers have paid more attention to cryptocurrency price forecasts. With the rise of deep learning, cryptocurrency forecasting has gained great importance. In this study, we present a long short-term memory (LSTM) algorithm that can be used to forecast the values of four types of cryptocurrencies: AMP, Ethereum, Electro-Optical System, and XRP. Mean square error (MSE), root mean square error (RMSE), and normalize root mean square error (NRMSE) analyses were used to evaluate the LSTM model. The findings obtained from these models showed that the LSTM algorithm had superior performance in predicting all forms of cryptocurrencies. Thus, it can be regarded as the most effective algorithm. The LSTM model provided promising and accurate forecasts for all cryptocurrencies. The model was applied to forecast the future closing prices of cryptocurrencies over a period of 180 days. The Pearson correlation metric was applied to assess the correlation between the prediction and target values in the training and testing processes. The LSTM algorithm achieved the highest correlation values in training (R = 96.73%) and in testing (96.09%) in predicting XRP currency prices. Cryptocurrency prices could be accurately predicted using the established LSTM model, which displayed highly efficient performance. The relevance of applying these models is that they may have huge repercussions for the economy by assisting investors and traders in identifying trends in the sales and purchases of different types of cryptocurrencies. The results of the LSTM model were compared with those of existing systems. The results of this study demonstrate that the proposed model showed superior accuracy based on the low prediction errors of the proposed system.
In our rapidly globalizing and digitalizing world, data transfer can be done quickly in multimedia, communication, computer systems, etc. On the other hand, a blockchain database is a technology that allows us to transfer assets such as digital money that we attribute value to. This technology, which eliminates centralization and distributes reliability and transparency among all users, is also known as the technology under virtual currencies such as Bitcoin and Ethereum. El-Salvador is the first country to accept Bitcoin as a legal currency. It is one of the most fundamental issues to wonder how this will affect the economy of El-Salvador and the spread of financial services to all members of society. In this study, it is examined how the process of accepting Bitcoin as legal money has an effect on the economy of El-Salvador and the percentage of people's access to financial services. Although there is not a great background to make an empirical assessment on the subject, it seems that a large part of the society has started to use Bitcoin through the official mobile application of the state. It is seen that even citizens who did not have a bank account before can access financial services with this method. In addition, the rapid increase in the investments coming to the country due to the tax advantages provides a great added value for the country's economy.
Sina Rafati Niya, Simon Bachmann, Claudio Brasser, Michael Bucher · 6 authors
Abstract Event tickets being sold in their electronic instances are subject to counterfeiting, profiteering, and black markets. Therefore, suitable service management mechanisms are required to overcome such deficits. This work designs, develops, and evaluates the approach of a Decentralized Ticketing platform—called DeTi—for managing the distribution of electronic event tickets and “regulating” the aftermarket. DeTi offers a dedicated service management functionality by operating through Smart Contracts of Ethereum, such that users can verify tickets’ validity for a given event. Especially, a new mechanism for users to detect fraudulent events is introduced, too. The evaluation performed indicates that DeTi invalidates or validates tickets efficiently via its decentralized and BC-based service management approach. By securing technically a set of underlying processes, DeTi obviates forging, replication, and scalping of tickets, allowing for a well-managed resale ecosystem of tickets based on and limited to the organizers’ initial pricing.
Marc Pilkington, Erdita Kumaraku, Kejsi Bushi, Katia Haveri
Albania is a small country of the West Balkans situated in Southeast Europe still in the early stages of distributed ledger technology (DLT) adoption. In this research note, we begin to investigate the cryptocurrency regulatory framework and propose a national blockchain roadmap for the country. Albania was one of the first European nations to elaborate a cryptocurrency regulatory framework aimed at safeguarding users from the dangers of fraud and imposing sanctions in situations of misuse. Our proposed national blockchain roadmap includes emerging priorities such as licensed entities, digital divide reduction, remittances digitisation, Ethereum 2.0, blockchain FDI, e-voting, and the quadruple helix system.
Abstract This work proposes smart auto mining (SAM) for resource‐efficient mining in a blockchain network. The SAM algorithm stops the miners when there is zero pending transaction and starts the miner when there is at least one transaction sent into the network. The miner listens to the network to identify when a transaction has been made by a node. The model does not need any instruction to start mining when there is a pending transaction. The results show that a private Ethereum network produced over 300% more blocks in a 12‐h period with 599,950 transactions compared to when SAM is applied. The proposed algorithm is also able to reduce the storage used by the chaindata by 14%. The overhead of mining is decreased by reducing the production of empty blocks in the network which saves energy, storage space, network bandwidth and computational complexity.
Abstract: The interchange of electronic health data across healthcare facilities is made possible via the health information exchange program. There is a potential for data manipulation in this. This article primarily focuses on using "Blockchain," i.e. one of the greatest technologies, to secure medical health data. Blockchain has demonstrated its outstanding qualities in the field of cryptocurrencies like bitcoin and Ethereum. This study employs the Secure Hash Algorithm (SHA), Simple Mail Transfer Protocol (SMTP), and AES Rijndael Algorithm (SMTP). Additionally, using the Naïve Bayes method, we forecast many heart illnesses related to this work.
Since the inception of Bitcoin in 2009, the market of cryptocurrencies has grown beyond initial expectations as daily trades exceed $10 billion. As industries become automated, the need for an automated fraud detector becomes very apparent. Detecting anomalies in real time prevents potential accidents and economic losses. Anomaly detection in multivariate time series data poses a particular challenge because it requires simultaneous consideration of temporal dependencies and relationships between variables. Identifying an anomaly in real time is not an easy task specifically because of the exact anomalistic behavior they observe. Some points may present pointwise global or local anomalistic behavior, while others may be anomalistic due to their frequency or seasonal behavior or due to a change in the trend. In this paper we suggested working on real time series of trades of Ethereum from specific accounts and surveyed a large variety of different algorithms traditional and new. We categorized them according to the strategy and the anomalistic behavior which they search and showed that when bundling them together to different groups, they can prove to be a good real-time detector with an alarm time of no longer than a few seconds and with very high confidence.
Abstract: Today’s OSNs are controlled by major companies such as Facebook, Instagram and Twitter who have complete control over user data. These companies store the user data in a centralized server which.This has several issues. For example, if their servers go down there no backup copies might be available and the chances of getting hacked are more in a centralized architecture. These companies can also censor the contents and post targeted ads in the user feeds. To overcome the drawbacks of the centralized OSNs, in this paper we are implementing a decentralized social media with the help of Ethereum smart contracts. Here, the data is not stored in a centralized server and the major disadvantages of centralized servers can be overcome by this approach.
Kota Chin, Keita Emura, Kazumasa Omote, Shingo Sato
In an open-bid auction, a bidder can know the budgets of other bidders. Thus, a sealed-bid auction that hides bidding prices is desirable. However, in previous sealed-bid auction protocols, it has been difficult to provide a ``fund binding'' property, which would guarantee that a bidder has funds more than or equal to the bidding price and that the funds are forcibly withdrawn when the bidder wins. Thus, such protocols are vulnerable to false bidding. As a solution, many protocols employ a simple deposit method in which each bidder sends a deposit to a smart contract, which is greater than or equal to the bidding price, before the bidding phase. However, this deposit reveals the maximum bidding price, and it is preferable to hide this information. In this paper, we propose a sealed-bid auction protocol that provides a fund binding property. Our protocol not only hides the bidding price and a maximum bidding price, but also provides fund binding, simultaneously. For hiding the maximum bidding price, we pay attention to the fact that usual Ethereum transactions and transactions for sending funds to a one-time address have the same transaction structure, and it seems that they are indistinguishable. We discuss how much bidding transactions are hidden. We also employ DECO (Zhang et al,. CCS 2020) that proves the validity of the data to a verifier in which the data are taken from a source without showing the data itself. Finally, we give our implementation which shows transaction fees required and compare it to a sealed-bid auction protocol employing the simple deposit method.
Faisal Albalwy, John McDermott, William G. Newman, Andy Brass · 5 authors
The successful implementation of pharmacogenetics (PGx) into clinical practice requires patient genomic data to be shared between stakeholders in multiple settings. This creates a number of barriers to widespread adoption of PGx, including privacy concerns related to the storage and movement of identifiable genomic data. Informatic solutions that support secure and equitable data access for genomic data are therefore important to PGx. Here we propose a methodology that uses smart contracts implemented on a blockchain-based framework, PGxChain, to address this issue. The design requirements for PGxChain were identified through a systematic literature review, identifying technical challenges and barriers impeding the clinical implementation of pharmacogenomics. These requirements included security and privacy, accessibility, interoperability, traceability and legal compliance. A proof-of-concept implementation based on Ethereum was then developed that met the design requirements. PGxChain's performance was examined using Hyperledger Caliper for latency, throughput, and transaction success rate. The findings clearly indicate that blockchain technology offers considerable potential to advance pharmacogenetic data sharing, particularly with regard to PGx data security and privacy, large-scale accessibility of PGx data, PGx data interoperability between multiple health care providers and compliance with data-sharing laws and regulations.
Open access
Pharmacogenetics and Drug Metabolism
Renal Transplantation Outcomes and Treatments
Innovative Microfluidic and Catalytic Techniques Innovation
In 2020, there will be 1% bulk sugar product returns. Direct return to warehouse; it is not known how much and what kind of sugar was returned. Changes in the number of uncontrolled product availability occur in the logistics sector. We designed a sugar volume return mechanism to verify the identity of the buyer, the amount and time of the transaction, using the steps of investigation, analysis, and system design that can implement. The application is based on the truffle test framework and smart contracts on the Ropsten test network on the Ethereum Metamask platform wallet, localhost memory, and a decentralized web-based dashboard. Input data on the smart contract so that during the Ropsten net test process, it will generate blocks, hash codes, and contract hashes as transaction details. It also displays a summary report and a blockchain transaction dashboard. How much volume will increase or decrease due to returns, buyers, type of sugar commodity, time, and volume of sugar during data transactions is known. The features developed for smart contracts are private, semi-public transactions with consensus proof of work as validation and verification of the success of transaction data records.
Blockchain is making a big impact in various applications, but it is also attracting a variety of cybercrimes. In blockchain, phishing transfers the victim’s virtual currency to make huge profits through fraud, which poses a threat to the blockchain ecosystem. To avoid greater losses, Ethereum, one of the blockchain platforms, can provide information to detect phishing fraud. In this study, to effectively detect phishing nodes, we propose a phishing node detection approach as message passing based graph convolution network. We first form a transaction network through the transaction records of Ethereum and then extract the information of nodes effectively via message passing. Finally, we use a graph convolution network to classify the normal and phishing nodes. Experiments show that our method is effective and superior to other existing methods.
Muhammad Abdul Ghoni, Ade Wirman Syafei, Kemal Ariza
This practical analysis and investigated research of the performing cryptocurrency investment during the January 2019-September 2021 period. This study is evaluating five cryptocurrencies within global Cryptocurencies market. Treynor and Jensen Index are utilized to measure each cryptocurrencies operation in the crypto currencies market. Moreover, the analysis of Islamic Legal maxim of blocking evils is precedenced than taking benefits in Cryptocurrency Market is applied. The Treynor and Jensen Index analysis approach is used to evaluate performance among the five cryptocurrencies, namely; Bitcoin (BTC), Ethereum (ETH), Binance Coin (BNB), Tether (USDT) and Cardano (ADA . The results of Treynor index indicate cryptocurrencies, namely; Tether (USDT), Ethereum (ETH), Cardano (ADA) assets carried the has a positive value means the performance of cryptocurrency is good as compare other Cryptocurrencies. However, the results of Jensen index show the four crypto assets, namely; Bitcoin (BTC), Ethereum (ETH), Tether (USDT), Cardano (ADA) have a negative Jensen value, these indicates the cryptocurrencies have low returns. The finding of the result from the analysis of the of Islamic Legal maxim of preventing evils is better than attracting benefits suggest to avoid cryptocurrency investment is priority rather than taking benefit from cryptocurrency investment
Ningyu He, Haoyu Wang, Lei Wu, Xiapu Luo · 6 authors
EOSIO, as one of the most representative blockchain 3.0 platforms, involves lots of new features, e.g., delegated proof of stake consensus algorithm and updatable smart contracts, enabling a much higher transaction per second and the prosperous decentralized applications (DApps) ecosystem. According to the statistics, it has reached nearly 18 billion USD, taking the third place of the whole cryptocurrency market, following Bitcoin and Ethereum. Loopholes, however, are hiding in the shadows. EOSBet, a famous gambling DApp, was attacked twice within a month and lost more than 1 million USD. No existing work has surveyed the EOSIO from a security researcher perspective. To fill this gap, in this paper, we collected all occurred attack events against EOSIO, and systematically studied their root causes, i.e., vulnerabilities lurked in all relying components for EOSIO, as well as the corresponding attacks and mitigations. We also summarized some best practices for DApp developers, EOSIO official team, and security researchers for future directions.
Security and privacy issues have become a major hindrance to the broad adoption of Ride-Hailing Services (RHSs). In this article, we introduce a new collusion attack initiated by the Ride-Hailing Service Provider (RHSP) and a driver that could easily link the real riders and their anonymous requests (credentials). Besides this attack, existing work requires heavy computations to execute user matching, and it is challenging for riders to verify matching results. Meanwhile, a malicious driver may cancel an assigned ride order due to its short distance. To address these issues, we present a RHS system named Nereus to support collusion resistance, efficiency, verifiability, and accountability. First, we integrate a smart contract into a Software Guard Extensions (SGX) enclave to establish aprivate smart contractfor collusion resistance. We use a Bloom filter to achieve efficient matching. Second, we leverage privacy-preserving range query and Merkle proofs to make matching results verifiable. Meanwhile, we adopt short group signatures to provide anonymous authentication and deposit commitments to hold the runaway driver accountable. We formally state and prove the security and privacy of Nereus. We build a prototype based on Ethereum and SGX to conduct extensive performance analysis in regard to gas costs, computational costs, and communication overhead. Experimental results show that Nereus significantly improves over existing schemes in terms of computational costs.
Today, in the world and in Ukraine, in particular, along with fiat money, there are cryptocurrencies in circulation. One type of cryptocurrency is non-fungible tokens (NFT). NFT is a type of digital asset created on the blockchain basis, which allows you to obtain ownership of a product that exists exclusively on the network (images, videos, animations). NFT opens up new opportunities for intellectual property objects. The purpose of the article is to research the theoretical foundations of cryptocurrency accounting, in particular one of its types, non non-fungible token (NFT). NFT framework is the ERC-721 (Ethereum Request for Comments 721) standard for issuing and trading non-fungible assets. The creation of legislative norms to regulate relations related to cryptocurrencies has just begun in Ukraine. The Law "On Virtual Assets" was adopted in Ukraine, but it has not entered into force. Accounting issues remain unsettled due to the lack of a regulatory framework.
Uyikumhe Damisa, Peter Olabisi Oluseyi, Nnamdi Nwulu
Inadequate gas supply is partly responsible for the energy shortfall experienced in some energy-poor nations. Favorable market conditions would boost investment in the gas supply sector; hence, we propose a blockchain-based fair, transparent, and secure gas trading scheme that facilitates peer-to-peer trading of gas. The scheme is developed using an Ethereum-based smart contract that receives offers from gas suppliers and bid(s) from the thermal plant operator. Giving priority to the cheapest offers, the smart contract determines the winning suppliers. This paper also proposes an economic dispatch model for gas-deficient plants. Conventional economic dispatch seeks to satisfy electric load demand whilst minimizing the total gas cost of generating units. Implicit in its formulation is the assumption that gas supply to generating units is sufficient to satisfy available demand. In energy poor nations, this is hardly the case as there is often inadequate gas supply and conventional economic dispatch is of little practical value. The proposed economic dispatch model’s objective function maximizes the quantity of available gas and determines the optimal power output of each generating unit. The mathematical formulation is verified using data from the Egbin thermal station which is the largest thermal station in Nigeria and is solved using the General Algebraic Modeling System (GAMS). Obtained results indicate the viability of the novel approach as it results in a net power gain of 35 MW. On the other hand, the smart contract proved effective in accurately selecting winning suppliers and making payment.