Maintenance of immutable vaccination records and provision of accessing the records in order to prove immunity has been the need of the hour. The recent spread of Covid19 and related uncertainty over vaccinations and immunity have made the search for a secure trustable system for reporting vaccination data more essential. Multiple digital, as well as paper-based solutions have been tested but none has been reported successful enough. In this paper, a technique has been proposed to solve the problem by introducing blockchain-based solution to maintain records of vaccination and proof of immunity for individuals. The purpose has been to present a safe and efficient solution to the problem and hence the model proposed is based on concepts of smart contracts and built over Ethereum blockchain. The paper goes on to give a detailed study of the technique based on discussions of its various aspects like design, development and feasibility.
Hyeong Joon Kim, Hye Hyeon Kim, Hosuk Ku, Kyung Don Yoo · 11 authors
<sec> <title>BACKGROUND</title> The Health Avatar Platform provides a mobile health environment with interconnected patient Avatars, physician apps, and intelligent agents (termed <i>IoA<sup>3</sup></i>) for data privacy and participatory medicine; however, its fully decentralized architecture has come at the expense of decentralized data management and data provenance. </sec> <sec> <title>OBJECTIVE</title> The introduction of blockchain and smart contract technologies to the legacy Health Avatar Platform with a clinical metadata registry remarkably strengthens decentralized health data integrity and immutable transaction traceability at the corresponding data-element level in a privacy-preserving fashion. A crypto-economy ecosystem was built to facilitate secure and traceable exchanges of sensitive health data. </sec> <sec> <title>METHODS</title> The Health Avatar Platform decentralizes patient data in appropriate locations (ie, on patients’ smartphones and on physicians’ smart devices). We implemented an Ethereum-based hash chain for all transactions and smart contract–based processes to guarantee decentralized data integrity and to generate block data containing transaction metadata on-chain. Parameters of all types of data communications were enumerated and incorporated into 3 smart contracts, in this case, a health data transaction manager, a transaction status manager, and an application programming interface transaction manager. The actual decentralized health data are managed in an off-chain manner on appropriate smart devices and authenticated by hashed metadata on-chain. </sec> <sec> <title>RESULTS</title> Metadata of each data transaction are captured in a Health Avatar Platform blockchain node by the smart contracts. We provide workflow diagrams each of the 3 use cases of data push (from a physician app or an intelligent agents to a patient Avatar), data pull (request to a patient Avatar by other entities), and data backup transactions. Each transaction can be finely managed at the corresponding data-element level rather than at the resource or document levels. Hash-chained metadata support data element–level verification of data integrity in subsequent transactions. Smart contracts can incentivize transactions for data sharing and intelligent digital health care services. </sec> <sec> <title>CONCLUSIONS</title> Health Avatar Platform and interconnected patient Avatars, physician apps, and intelligent agents provide a decentralized blockchain ecosystem for health data that enables trusted and finely tuned data sharing and facilitates health value-creating transactions with smart contracts. </sec>
Supply chain integration remains an elusive goal for the construction and engineering industry. The high degree of fragmentation and the reliance on third-party financial institutions has pushed the physical and financial supply chains apart. The paper demonstrates how blockchain-based crypto assets (crypto currencies and crypto tokens) can address this limitation when used for conditioning the flow of funds based on the flow of products. The paper contrasts the integration between cash and product flows in supply chains that rely on fiat currencies and crypto assets for their payment settlement. Two facets of crypto asset-enabled integration, atomicity and granularity, are further introduced. The thesis is validated in the context of construction progress payments. The as-built data captured by unmanned aerial and ground vehicles was passed to an autonomous smart contract-based method that utilizes crypto-currencies and crypto tokens for payment settlement; the resulting payment datasets, written to the Ethereum blockchain, were analyzed in terms of their integration of product and cash flow. The work is concluded with a discussion of findings and their implications for the industry.
In this contribution we extend an ontology for modelling agents and their interactions, called Ontology for Agents, Systems, and Integration of Services (in short, OASIS), with conditionals and ontological smart contracts (in short, OSCs). OSCs are ontological representations of smart contracts that allow to establish responsibilities and authorizations among agents and set agreements, whereas conditionals allow one to restrict and limit agent interactions, define activation mechanisms that trigger agent actions, and define constraints and contract terms on OSCs. Conditionals and OSCs, as defined in OASIS, are applied to extend with ontological capabilities digital public ledgers such as the blockchain and smart contracts implemented on it. We will also sketch the architecture of a framework based on the OASIS definition of OSCs that exploits the Ethereum platform and the Interplanetary File System.
In this contribution we extend an ontology for modelling agents and their interactions, called Ontology for Agents, Systems, and Integration of Services (in short, OASIS), with conditionals and ontological smart contracts (in short, OSCs). OSCs are ontological representations of smart contracts that allow to establish responsibilities and authorizations among agents and set agreements, whereas conditionals allow one to restrict and limit agent interactions, define activation mechanisms that trigger agent actions, and define constraints and contract terms on OSCs. Conditionals and OSCs, as defined in OASIS, are applied to extend with ontological capabilities digital public ledgers such as the blockchain and smart contracts implemented on it. We will also sketch the architecture of a framework based on the OASIS definition of OSCs that exploits the Ethereum platform and the Interplanetary File System.
Muhammad Fajar Sidiq, Akbari Indra Basuki, Halim Firdaus, Muhammad Aldi Baihaqi
Pengawasan jaringan pada beberapa kantor yang berlokasi berjauhan sangat sulit dilakukan kerana keterbatasan tenaga ahli, biaya, dan teknologi pendukung. Penelitian yang sudah ada tidak dapat menyediakan sistem pengawasan jaringan yang mampu menjamin tiga aspek keamanan sekaligus, yaitu: availability, integrity, dan confidentiality. Teknologi blockchain mampu menyediakan sistem pengawasan jaringan secara terpusat dan aman dengan menjamin keamanan sistem komunikasi pelaporan dan sistem basis data pelaporan. Penelitian ini bertujuan untuk menyajikan purwarupa sistem pengawasan konfigurasi dan statistik jaringan menggunakan jejaring blockchain Ethereum. Metode pengawasan mengharuskan program controller pada setiap jaringan kantor untuk secara berkala menarik informasi flow-rules dari setiap perangkat jaringan dan melaporkan data tersebut dalam sebuah transaksi ke jejaring blockchain. Pada penelitian ini dianalisa dua jenis skema pengiriman transaksi: transaksi berbasis smart contract dan transaksi berbasis zero-payment. Berdasarkan hasil pengujian, transaksi berbasis zero-payment secara rerata hanya membutuhkan sekitar 6 % dari biaya transaksi smart contract. Perkiraan biaya bulanan untuk pensamplingan informasi setiap 10 menit adalah sekitar 1,19 ether per-perangkat jaringan. Meskipun demikian, metode pada penelitian ini lebih sesuai untuk diterapkan pada jejaring Ethereum jenis Proof-of-Authority (PoA) dibandingkan jenis Proof-of-Work (PoW) karena harga Ether yang mahal. AbstractCentralized monitoring of remote networks is hard to implement due to the high cost, lack of experts, and the missing key technologies. The existing researches are unable to provide a secure, centralized monitoring system that satisfies three security aspects, namely: availability, integrity, and confidentiality. Blockchain technology meets those three requirements by providing a reliable reporting and immutable database system. In this paper, we proposed a prototype of a centralized monitoring system that records network statistics and configurations into the blockchain ledger. The method requires the network controller to periodically fetch network information from every network device and submit it as a single blockchain transaction. We compare two kinds of transaction schema, smart-contract based and zero-payment based reporting schemes. The evaluations show that zero-payment transactions only cost 6 % of the smart-contract transactions. The estimation of the monthly cost is 1.19 ether per-device for 10-minutes data sampling. Nevertheless, the proposed method is applicable only for the Proof-of-Authority (PoA) Ethereum networks. It is not feasible for the Ethereum main network that uses Proof-of-Work (PoW) due to the high cost of Ether.
Beyond an emerging popular web applications runtime supported in almost all commodity browsers, WebAssembly (WASM) is further regarded to be the next-generation execution environment for blockchain-based applications. Indeed, many popular blockchain platforms such as EOSIO and NEAR have adopted WASM-based execution engines. Most recently, WASM has been favored by Ethereum, the largest smart contract platform, to replace the state-of-the-art EVM. However, whether and how well current WASM outperforms EVM on blockchain clients is still unknown. This article conducts the first measurement study to understand the performance on WASM VMs and EVM for executing smart contracts for blockchain-based applications. To our surprise, the current WASM VM does not provide expected satisfactory performance. The overhead introduced by WASM is really non-trivial. Our results shed the light on challenges when deploying WASM in practice, and provide insightful implications for improvement space.
As the most popular blockchain that supports smart contracts, there are already more than 296 thousand kinds of cryptocurrencies built on Ethereum. However, not all cryptocurrencies can be controlled by users. For example, some money is permanently locked in wallets' accounts due to attacks. In this paper, we conduct the first systematic investigation on locked cryptocurrencies in Ethereum. In particular, we define three categories of accounts with locked cryptocurrencies and develop a novel tool named CLUE to discover them. Results show that there are more than 216 million dollars value of cryptocurrencies locked in Ethereum. We also analyze the reasons (i.e., attacks/behaviors) why cryptocurrencies are locked. Because the locked cryptocurrencies can never be controlled by users, avoid interacting with the accounts discovered by CLUE and repeating the same mistakes again can help users to save money.
EIP-1559 is a proposal to make several tightly coupled additions to Ethereum's transaction fee mechanism, including variable-size blocks and a burned base fee that rises and falls with demand. This report assesses the game-theoretic strengths and weaknesses of the proposal and explores some alternative designs.
Everyone should have the right to expression and opinion without interference. Nevertheless, Internet censorship is often misused to block freedom of speech. The distributed ledger technology provides a globally shared database that is geographically distributed and that cannot be controlled by a central authority. Blockchain is an emerging technology that enabled distributed ledgers and has recently been employed for building various types of applications. This paper demonstrates a unique application of blockchain technologies to create a platform that supports the freedom of expression. The paper adapts permissionless and public blockchains in order to leverage their advantages of providing an immutable and tamper-proof digital ledger. The study shows the blockchain potential for providing censorship-resistant publication platform. The paper presents and evaluates possible methods for building such system using the Bitcoin and Ethereum blockchain networks. Our results demonstrate that the Ethereum blockchain is much more beneficial for our system as it requires much lower cost than Bitcoin. to use as a platform to allow freedom of speech.
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
There has been wide range of applications involving smart home systems for user comfort and accessibility to essential commodities. Users enjoy featured home services supported by the IoT smart devices. These IoT devices are resource-constrained, incapable of securing themselves and can be easily hacked. Edge computing can provide localized computations and storage which can augment such capacity limitations for IoT devices. Furthermore, blockchain has emerged as technology with capabilities to provide secure access and authentication for IoT devices in decentralized manner. In this paper, we propose an authentication scheme which integrate attribute based access control using smart contracts with ERC-20 Token (Ethereum Request For Comments) and edge computing to construct a secure framework for IoT devices in Smart home system. The edge server provide scalability to the system by offloading heavier computation tasks to edge servers. We present system architecture and design and discuss various aspects related to testing and implementation of the smart contracts. We show that our proposed scheme is secure by thoroughly analysing its security goals with respect to confidentiality, integrity and availability. Finally, we conduct a performance evaluation to demonstrate the feasibility and efficiency of the proposed scheme.
Abstract: In the contemporary world, Ethereum is a very reliable financial saving among cryptocurrencies. It is also well known as a blockchain platform for creating and launching its own cryptocurrency. The applications run on Ethereum executed by a platform-specific cryptographic token, ether. During 2014, Ethereum had launched a pre-sale for ether, which had received an overwhelming response. Ether is used broadly for two purposes: it is traded as a digital currency exchange like other cryptocurrencies, and it is used inside Ethereum to run applications and even to monetize work. It should be noticed that the smart contract has brought a significant share of the success to Ethereum. The smart contract is a computer programme that independently performs assigned tasks between network participants without the participation of a third trusted party. Smart contracts and their intranet transactions have facilitated the rapid expansion of the Ethereum network. Smart contracts are widely represented on the market, either as electronic transaction payments or as applications for the implementation of logistics supplies, gambling, and other sectors. These transactions are irreversible and fully tracked online. Whereas the electronic records are available in a public distributed ledger and include data about user addresses, whereas the real names are hidden. The article explains the usage of decentralized accounts and their electronic transactions in the Ethereum network. The results are presented through different application sectors. Additionally, a new method for extracting blockchain records through node cluster via IPFS path is implemented in the research.
Abstract This system is designed by using Lolin D32 as the processor dan MPL3115A2 for the sensors. This system is designed to show that devices that based on Internet of Things (IoT) could be secured by using blockchain technology. The blockchain technology is based on Ethereum which will be tested in Ropsten Testnet network. Processor module connects to Internet through WiFi module which is one of the Lolin D32 features. This WiFi module connects to router which is used for designing and testing the system. This system wants to prove that the data which are acquired from sensor module MPL3115A2 (altitude, temperature and pressure) and positioning data could be sign and verify within the processor Lolin D32. Before sending the data, the data will be formatted. Data will be stored in smart contract. The smart contract is an Ethereum program which is written using Solidity language. This smart contract is delployed into Ropsten network. The numbers of testing that have been carried out are 516 times. These testings proved as success. The data which were sent to Ropsten network could be proved that they were recorded successfully. These are done by checking through etherscan.io.
Xuan Luo, Zehua Wang, Wei Cai, Xiuhua Li · 5 authors
Traditional centralized token exchange (CEX) has been suffering from hacking due to the centralized management of users’ tokens. In contrast, decentralized token exchange (DEX) maintains users’ assets by smart contracts in a decentralized manner, but introduces additional overhead in terms of gas fee and transaction confirmation latency. Hybrid decentralized token exchange (HEX) has been proposed to combine the benefits of CEX and DEX. However, existing HEX is criticized for two issues. First, trading transactions are time-consuming and expensive for frequent token traders. Second, excessive simultaneous transactions might cause the pending transaction congestion in the Ethereum network. In this paper, we propose a payment channel based HEX, which extends existing solutions by adding a new payment channel layer to benefit frequent traders and alleviate the pending transaction congestion. Besides, we propose the very first gas-price vs. transaction-confirmation-latency function to guide Ethereum transaction issuers to choose an optimal gas price that minimizes the overall cost. Extensive simulations are conducted to compare the cost in the proposed HEX with that in the conventional HEX. The results demonstrate the effectiveness of our proposed mechanism in terms of reducing gas fees and transaction confirmation latency for frequent traders as well as the pending transaction congestion in Ethereum.
EIP-1559 is a proposal to make several tightly coupled additions to\nEthereum's transaction fee mechanism, including variable-size blocks and a\nburned base fee that rises and falls with demand. This report assesses the\ngame-theoretic strengths and weaknesses of the proposal and explores some\nalternative designs.\n
The study aims to elaborate on the Shari’ah issues regarding cryptocurrencies. The research found that overall Shari’ah challenges in studying this unprecedent issue can be confined to Bitcoin since it is the first cryptocurrency with its own protocol and laws, and the later versions of the cryptocurrency started using the protocol of Bitcoin. Bitcoin was distinguished being the only cryptocurrency that is classified as decentralized, whereas the subsequent versions of the currencies, which were introduced as an alternative to Bitcoin, such as Ethereum, were centralized by their issuer. Also, the tokens are merely representing the assets which were collected through it. The overall Shari'ah issues were summarized in terms of its asset and monetary consideration, impact of price fluctuations, decentralization, anonymity, and the mechanism of mining which PoW (Proof-of-Work) and PoS (Proof-of-Stake). This study has concluded on the Shari’ ah permissibility of the PoW system which is used in Bitcoin, and PoS system which is used in Ethereum. The contract is based on Ju’alah contract. As a principle, the study could not conclude the Shari’ah non-permissibility of exchanging, trading or investing in Bitcoin, and similar cryptocurrencies. These cryptocurrencies are subjected to all the guidelines related to exchange of currencies (sarf) and rulings of Riba buyu’ (sale on credit) and Riba duyun (interest on debt). Also, it will be subjected to monetary Zakat rulings. However, dealing with mining groups, electronic platforms, as well as investing in these currencies through various websites, may contain executing agreements and contracts that contain conditions not compliant to Shari’ah. These agreements should be examined in the light of the provisions of the Islamic law. Also, users should be cautious against falling into the net of fraudsters on the Internet. The research recommends to hold-up investing in these recent currencies because of the rapid volatility and to avoid exposing the wealth to high risk.
Smart contracts — computer protocols that regulate the exchange of crypto-assets in trustless environments — have become popular with the spread of blockchain technologies. A landmark security property of smart contracts is liquidity: in a non-liquid contract, it may happen that some assets remain frozen, i.e. not redeemable by anyone. The relevance of this issue is witnessed by recent liquidity attacks to Ethereum, which have frozen hundreds of USD millions. We address the problem of verifying liquidity on BitML, a DSL for smart contracts with a secure compiler to Bitcoin, featuring primitives for currency transfers, contract renegotiation and consensual recursion. Our main result is a verification technique for liquidity. We first transform the infinite-state semantics of BitML into a finite-state one, which focusses on the behaviour of a chosen set of contracts, abstracting from the moves of the context. With respect to the chosen contracts, this abstraction is sound, i.e. if the abstracted contract is liquid, then also the concrete one is such. We then verify liquidity by model-checking the finite-state abstraction. We implement a toolchain that automatically verifies liquidity of BitML contracts and compiles them to Bitcoin, and we assess it through a benchmark of representative contracts.
Smart contracts - computer protocols that regulate the exchange of crypto-assets in trustless environments - have become popular with the spread of blockchain technologies. A landmark security property of smart contracts is liquidity: in a non-liquid contract, it may happen that some assets remain frozen, i.e. not redeemable by anyone. The relevance of this issue is witnessed by recent liquidity attacks to Ethereum, which have frozen hundreds of USD millions. We address the problem of verifying liquidity on BitML, a DSL for smart contracts with a secure compiler to Bitcoin, featuring primitives for currency transfers, contract renegotiation and consensual recursion. Our main result is a verification technique for liquidity. We first transform the infinite-state semantics of BitML into a finite-state one, which focusses on the behaviour of a chosen set of contracts, abstracting from the moves of the context. With respect to the chosen contracts, this abstraction is sound, i.e. if the abstracted contract is liquid, then also the concrete one is such. We then verify liquidity by model-checking the finite-state abstraction. We implement a toolchain that automatically verifies liquidity of BitML contracts and compiles them to Bitcoin, and we assess it through a benchmark of representative contracts.
In this study we discuss the determinants of the BRICS and GCC stock market returns during the COVID-19 outbreak. We employ the OLS regression to discern how crypto-currencies, VIX, oil, GOLD prices, and the number of COVID-19 cases and deaths, affect the Gulf and BRICS stock markets. We find that Bitcoin and Ethereum can generate benefits from portfolio diversification and hedging strategies but not from safe haven strategies for Russia, Brazil, Abu-Dhabi, Bahrain, and Qatar financial investors during the COVID-19 outbreak. Our results reveal that Gold is neither hedge nor a safe haven but is only an effective diversifier for investors during the COVID-19 outbreak. The results indicated that among all the BRICS and GCC stock indexes, the expected volatility of the US stock market has an effect only on china and Kuwait financial markets. Finally, our results show that the growth rate of confirmed COVID-19 cases has a negative impact only on South Africa and Brazil stock market.
Decentralized blockchain platforms have enabled the secure exchange of crypto-assets without the intermediation of trusted authorities. To this purpose, these platforms rely on a peer-to-peer network of byzantine nodes, which collaboratively maintain an append-only ledger of transactions, called blockchain. Transactions represent the actions required by users, e.g. the transfer of some units of crypto-currency to another user, or the execution of a smart contract which distributes crypto-assets according to its internal logic. Part of the nodes of the peer-to-peer network compete to append transactions to the blockchain. To do so, they group the transactions sent by users into blocks, and update their view of the blockchain state by executing these transactions in the chosen order. Once a block of transactions is appended to the blockchain, the other nodes validate it, re-executing the transactions in the same order. The serial execution of transactions does not take advantage of the multi-core architecture of modern processors, so contributing to limit the throughput. In this paper we develop a theory of transaction parallelism for blockchains, which is based on static analysis of transactions and smart contracts. We illustrate how blockchain nodes can use our theory to parallelize the execution of transactions. Initial experiments on Ethereum show that our technique can improve the performance of nodes.
Florian Adamsky, Daniel Kaiser, Michael Steglich, Thomas Engel
Distributed Hash Table (DHT) protocols, such as Kademlia, provide a decentralized key-value lookup which is nowadays integrated into a wide variety of applications, such as Ethereum, InterPlanetary File System (IPFS), and BitTorrent. However, many security issues in DHT protocols have not been solved yet. DHT networks are typically evaluated using mathematical models or simulations, often abstracting away from artefacts that can be relevant for security and/or performance. Experiments capturing these artefacts are typically run with too few nodes.
Aasim Ullah, S.M. Shahnewaz Siddiquee, Md Akbar Hossain, Sayan Kumar Ray
Data security of present-day power systems, such as the electricity market, has spurred global interest in both industry and academia. The electricity market can either be regulated (state-controlled entrance, policies, and pricing) or deregulated (open for competitors). While the security threats in a deregulated electricity market are commonly known and have been investigated for years, those in a regulated market still have scope for extensive research. Our current work focuses on exploring the data security of the regulated electricity market, and the regulated New Zealand Electricity Market (NZEM) has been considered for this research. Although the chances of cyberattacks on state-controlled regulated electricity market are relatively less, different layers of the current SCADA systems do pose some threats. In this context, we propose a decentralized Ethereum Blockchain-based end-to-end security prototype for a regulated electricity market such as the NZEM. This prototype aims to enhance data security between the different layers of the current SCADA systems. The detailed operation process and features of this prototype are presented in this work. The proposed prototype has prospects of offering improved data security solutions for the regulated electricity market.