Walaa AlKhader, Khaled Salah, Andrei Sleptchenko, Raja Jayaraman · 6 authors
Coronavirus 2019 (COVID-19) has disclosed the deficiencies and limitations of the existing manufacturing and supply chain systems used for medical devices and supplies. It enforces the necessity to accelerate the shift towards decentralized digital manufacturing and supply chain networks. This paper proposes a blockchain-based solution for decentralized digital manufacturing of medical devices and their supply. We develop Ethereum smart contracts to govern and track transactions in a decentralized, transparent, traceable, auditable, trustworthy, and secure manner. This allows overcoming certain issues hindering the transition towards decentralized digital manufacturing and supply, including trusted traceability, attestations, certifications, and secured intellectual property (IP) rights. We incorporate the decentralized storage of the InterPlanetary file system (IPFS) into the Ethereum blockchain to store and fetch Internet of things (IoT)-based devices records and additional manufacturing and supply details. We present the system architecture and algorithms along with their full implementation and testing details. Furthermore, we present cost and security analyses to show that the proposed solution is cost-efficient and resilient against well-known vulnerabilities and security attacks. We make our smart contracts code publicly available on GitHub.
operates on a blockchain full node maintained directly by the DApp owner (i.e., an in-house RPC node) or a set of nodes hosted by a third party (i.e., a third-party RPC service) intended to ease DApp deployment. Given the ever-growing blockchain states (e.g., 130 GB and 1.8 TB for a fully synced and an archived Ethereum node, respectively, as of 2018), the RPC service plays an increasingly important role in the DApp ecosystem, scaling DApp clients to low-end mobile devices and web browsers. Major blockchains today flock to roll out RPC supports, which spawn a good number of services in practice, including nine service providers (as is evaluated in this work) supporting the Ethereum's JSON-RPC interface [16], blockchain.info [5] with Bitcoin's JSON-RPC [2], dfuse.io [13] and greymass.com [39] with EOSIO's Chain API [6], stellar.org [46] with Stellar Horizon [23], etc. These services host the majority of DApps; for instance, at least 63% of Ethereum based DApps use one RPC service [10]. DApp clients RPC service JSON-RPC Block/tx synchronization Blockchain peers
Alexander Garrido, Leonardo Juan Ramírez López, Nicolas Beltrán Álvarez
Since their introduction, blockchain applications have been numerous and varied, allowing for the resolution of many issues previously considered insurmountable. In the field of health records management, the storing of electronic health records (EHRs) has been one of the topics of greatest interest to academics, though its implementation using blockchain technology has not been without flaws. Therefore, the objective of this research is to select the blockchain protocol that provides the best performance given the scalability issue in the implementation of a BT-based EHR system in a high-priority healthcare institution (HP–HI). To achieve this objective, a discrete-event simulation tool and the AHP technique are both combined, to model the selected blockchain protocols and to analyze the output data. Ethereum protocol emerges as the platform with the best overall performance for the HP-HI under consideration. This result is based on a rigorous analysis of three blockchain protocols–Ethereum, Dogecoin and Bitcoin–and five criteria to evaluate the scalability in BT-based EHR systems: sent transactions, received transactions, failed transactions, nodes, and cost. This research is the first practical study to assess the implementation of BT-based EHR systems in the context of the Colombian health system. This research also integrates a general evaluation framework that can be replicated to other similar HCs. In light of the scalability problem studied, Ethereum protocol is consistently the most appropriate blockchain solution for the selected HP-HI. This result is in line with previous research on BT-based EHR systems. The problem-solving integrated approach discussed in this research can also be replicated to other similar HCs to improve their performance against pandemics such as COVID-19.
Ecumenical carbon dioxide (CO2) emission emanates from car, bus, taxi, and motorcycle is around 45%. Electric vehicle could be the major contributor to abbreviate the pollution level in a transportation sector. According to the Forbes report the ecumenical passenger electric vehicle demand expected to reach 15% in 2025, and 23% in 2030. This research provides a blockchain predicated solution for a pre-owned electric vehicle market that could engender a trust, transparency, immutable records, and an efficient way to track the entire life cycle of a futuristic electric vehicle supply chain. At present most of the pre-owned electric conveyance purchase transpires through the third-party accommodations, websites, and mobile applications. This does not provide the authentic information on electric conveyance history, charging capabilities of the battery, history of the charging records, and performance of the driver (wear and tear affect battery life). Our solution implemented utilizing hybrid blockchain technology. Each stakeholder assigned with the Ethereum blockchain address to track the vehicle records as a distributed ledger. This design considered electric vehicle manufacturer, charging station, battery manufacturer, road convey ascendancy as major stakeholders. Astute contract designed with solidity programming. Truffle platform used to deploy keenly intellective contract in private blockchain that ascertain the privacy of electric conveyance owners and other stakeholders. Meta mask a mobile application utilized kovan network for tracking vehicle in a public blockchain. This application tested with 0.1 Ether for each transaction. Blockchain Electric Vehicle Cloud of Things (BEVCoT) concept proposed to integrate the IoT-Blockchain application in a cloud environment.
Ruba Awadallah, Azman Samsudin, Je Sen Teh, Mishal Almazrooie
Due to its wide accessibility, cloud services are susceptible to attacks. Data manipulation is a serious threat to data integrity which can occur in cloud computing - a relatively new offering under the umbrella of cloud services. Data can be tampered with, and malicious actors could use this to their advantage. Cloud computing clients in various application domains want to be assured that their data is accurate and trustworthy. On another spectrum, blockchain is a tamper-proof digital ledger that can be used alongside cloud technology to provide a tamper-proof cloud computing environment. This paper proposes a scheme that combines cloud computing with blockchain that assures data integrity for all homomorphic encryption schemes. To overcome the cloud service provider's (CSP) ultimate authority over the data, the proposed scheme relies on the Byzantine Fault Tolerance consensus to build a distributed network of processing CSPs based on the client requirements. After certain computations performed by all CSPs, they produce a master hash value for their database. To ensure immutable data is produced, master hash values are preserved in Bitcoin or Ethereum blockchain networks. The master hash values can be obtained by tracking the block header address for verification purposes. A theoretical analysis of the overhead costs associated with creating master hash values for each of the cryptocurrencies is presented. We found that Ethereum leads to lower client financial costs and better online performance than Bitcoin. We also specify the data security requirements the proposed scheme provides, the ground-level implementation, and future work. The proposed verification scheme is based on public cryptocurrency as a back-end service and does not require additional setup actions by the client other than a wallet for the chosen cryptocurrency.
Ahmad Musamih, Raja Jayaraman, Khaled Salah, Haya R. Hasan · 6 authors
Distribution and delivery of Coronavirus 2019 (COVID-19) vaccines have become challenging after their emergence. Today's platforms and systems leveraged for managing data related to COVID-19 vaccines' distribution and delivery fall short in providing transparency, trackability and traceability, immutability, audit, and trust features. Also, they are vulnerable to the single point of failure problem due to centralization. Such limitations hindering the safe, secure, transparent, trustworthy, and reliable distribution and delivery process of COVID-19 vaccines. In this paper, we propose an Ethereum blockchain-based solution for managing data related to COVID-19 vaccines' distribution and delivery. We develop smart contracts to automate the traceability of COVID-19 vaccines while ensuring data provenance, transparency, security, and accountability. We integrate the Ethereum blockchain with off-chain storage to manage non-critical and large-sized data. We present algorithms and discuss their full implementation, testing, and validation details. We evaluate the proposed solution by performing cost and security analysis as well as comparing it with the existing non-blockchain and blockchain-based solutions. Performance evaluation results reveal that the proposed solution is low-cost, and our smart contracts are secure enough against possible attacks and vulnerabilities. The smart contracts code along with testing scripts is made publicly available.
Open access
Blockchain Technology Applications and Security
Pharmaceutical Quality and Counterfeiting
Innovative Microfluidic and Catalytic Techniques Innovation
Decentralized Applications (DApps) are increasingly developed and deployed on blockchain platforms such as Ethereum. DApp fingerprinting can identify users' visits to specific DApps by analyzing the resulting network traffic, revealing much sensitive information about the users, such as their real identities, financial conditions and religious or political preferences. DApps deployed on the same platform usually adopt the same communication interface and similar traffic encryption settings, making the resulting traffic less discriminative. Existing encrypted traffic classification methods either require hand-crafted and fine-tuning features or suffer from low accuracy. It remains a challenging task to conduct DApp fingerprinting in an accurate and efficient way. In this paper, we present GraphDApp, a novel DApp fingerprinting method using Graph Neural Networks (GNNs). We propose a graph structure named Traffic Interaction Graph (TIG) as an information-rich representation of encrypted DApp flows, which implicitly reserves multiple dimensional features in bidirectional client-server interactions. Using TIG, we turn DApp fingerprinting into a graph classification problem and design a powerful GNN-based classifier. We collect real-world traffic datasets from 1,300 DApps with more than 169,000 flows. The experimental results show that GraphDApp is superior to the other state-of-the-art methods in terms of classification accuracy in both closed- and open-world scenarios. In addition, GraphDApp maintains its high accuracy when being applied to the traditional mobile application classification.
Mohammad Madine, Khaled Salah, Raja Jayaraman, Yousof Al-Hammadi · 6 authors
Blockchain technology has the potential to revolutionize industries by offering decentralized, transparent, data provenance, auditable, reliable, and trustworthy features. However, cross-chain interoperability is one of the crucial challenges preventing widespread adoption of blockchain applications. Cross-chain interoperability represents the ability for one blockchain network to interact and share data with another blockchain network. Contemporary cross-chain interoperability solutions are centralized and require re-engineering of the core blockchain stack to enable inter-communication and data sharing among heterogeneous blockchain networks. In this paper, we propose an application-based cross-chain interoperability solution named appXchain which allows blockchain networks of any architecture type and industrial focus to inter-communicate, share data, and make requests. Our solution utilizes the decentralized applications as a distributed translation layer that is capable of communicating and understanding multiple blockchain networks, thereby delegating requests and parameters among them. The architecture uses incentivized verifier nodes that maintain the integrity of shared data facilitating them to be readable by the entities of their network. We define and describe the roles and requirements of major entities of inter-operating blockchain networks in the context of healthcare. We present a detailed explanation of the sequence of interactions needed to share an Electronic Medical Record (EMR) document from one blockchain network to another along with the required algorithms. We implement the appXchain solution with Ethereum-based smart contracts for two hospitals and also present its cost and security analysis. We have made our smart contracts code and testing scripts publicly available.
David Nadler Prata, H. X. Araujo, Cleórbete Santos
This work begins with an explanation of fundamental concepts about Bitcoin and Blockchain and then explores the main definitions of smart contracts in the updated literature, demonstrates some categories of smart contracts, explores the most widely used platforms that support smart contracts, and gives greater prominence to the Ethereum platform for its more robust characteristics regarding the creation and storage of this type of contract. It then concludes by demonstrating the advantages of smart contracts in relation to traditional contracts, as well as addressing their legal validity.
Sasha Shilina, Dato Kavazi, Victor Smirnov, Viktor Smirnov · 9 authors
The advent of blockchain technology has led to a massive wave of different decentralized ledger technology (DLT) solutions. Such projects as Bitcoin and Ethereum have shifted the paradigm of how to transact value in a decentralized manner, but their various core technologies have their own advantages and disadvantages. This paper aims to describe an alternative to modern decentralized financial networks by introducing the Humanode network. Humanode is a network safeguarded by cryptographically secure bio-authorized nodes. Users will be able to deploy nodes by staking their encrypted biometric data. This approach can potentially lead to the creation of a public, permissionless financial network based on consensus between equal human nodes with algorithm-based emission mechanisms targeting real value growth and proportional emission. Humanode combines different technological stacks to achieve a decentralized, secure, scalable, efficient, consistent, immutable, and sustainable financial network: 1) a bio-authorization module based on cryptographically secure neural networks for the private classification of 3D templates of users' faces 2) a private Liveness detection mechanism for identification of real human beings 3) a Substrate module as a blockchain layer 4) a cost-based fee system 5) a Vortex decentralized autonomous organization (DAO) governing system 6) a monetary policy and algorithm, Fath, where monetary supply reacts to real value growth and emission is proportional. All of these implemented technologies have nuances that are crucial for the integrity of the network. In this paper we address these details, describing problems that might occur and their possible solutions. The main goal of Humanode is to create a stable and just financial network that relies on the existence of human life.
Blockchain consensus, which enables nodes on a peer-to-peer network to agree on the same ledger history, is the core element of blockchain systems. In many blockchain systems, a node chosen as a block proposer, in accordance with the consensus protocol, generates a block, and each node chooses a chain to extend by a fork-choice rule. This study introduces saving attacks, a new kind of attack that prevents nodes from reaching a consensus. In saving attacks, the adversary “saves” its rights to propose blocks during a temporal consensus failure and utilizes them later to cause another consensus failure. As a result, the blockchain suffers from poor performance and high latency to block finalization. We study the effect of saving attacks on various fork-choice rules, including those that Ethereum 2.0 plans to employ.We simulate saving attacks on the longest-chain rule, Greedy Heaviest-Observed Sub-Tree (GHOST), latest-message-driven (LMD) GHOST, and fresh-message-driven (FMD) GHOST.We show that the saving attack has a very large negative impact on the consensus. For example, we observe that under a certain condition, an adversary with 30% of the total stake that has saved its blocks for 32 minutes succeeds in preventing a consensus against LMD GHOST for 83 minutes in the context of Ethereum 2.0. We also show that FMD GHOST decreases the attack duration to approximately 6.4 minutes under the same conditions. Our results are applicable to all slot-based proof-of-stake blockchains, not just Ethereum 2.0.
The Symposium’s scope covers the key research areas of the Department: from measurement \ntheory and digital signal processing, through artificial intelligence and bioinformatics to cyber-physical systems, dependability, and security.
Francis Liu, Natalie Packham, Meng-Jou Lu, Wolfgang Karl Härdle
The introduction of derivatives on Bitcoin enables investors to hedge risk exposures in cryptocurrencies. Because of volatility swings and jumps in cryptocurrency prices, the traditional variance-based approach to obtain hedge ratios may not be suitable for hedgers. In this work, we consider two extensions of the traditional approach: first, different dependence structures are modelled by different copulae, such as the Gaussian, Student-t, Normal Inverse Gaussian and Archimedean copulae; second, different risk measures, such as value-at-risk, expected shortfall and spectral risk measures are employed to find the optimal hedge ratio. Extensive out-of-sample tests using the data from the time period December 2017 until May 2021 give insights in the practice of hedging various cryptos and crypto indices, including Bitcoin, Ethereum, Cardano, the CRIX index and a number of crypto-portfolios. Evidence shows that BTC futures can effectively hedge BTC and BTC-involved indices. This promising result is consistent across different risk measures and copulae except for the Frank copula. On the other hand, we observe complex and diverse dependence structures between non-BTC-related cryptocurrencies and the BTC futures. As a consequence, the hedge performance of non-BTC-related cryptocurrencies is mixed and even suitable for some assets.
In this paper we present a blockchain based system for the supply chain management of a particular Italian bread. Goal of the system is to guarantee a transparent and auditable traceability of the Carasau bread where each actor of the supply chain can verify the quality of the products and the conformity to the normative about the hygienic-sanitary conditions along the chain. To realize this system we relied on the Blockchain and the Internet of Thing technologies in order to provide a trustless environment, in which trust is placed in cryptography, in mathematical operations and on the network, and not in public or private companies. Thanks to the use of digital technologies the system aims to reduce the data entry errors and the risk of tampering. Our system is designed so that along the supply chain, the nodes equipped with several sensors directly communicate their data to Raspberry Pi units that elaborate and transmit them to Interplanetary File System and to the Ethereum Blockchain. Furthermore, we designed ad hoc Radio Frequency Identification and Near Field communication tags to shortly supply the proposed system with information about the products and batches. The dedicated RFID tags robustness during on-bread operation was numerically tested. The system will easily allow end consumers to have a transparent view on the whole journey from raw material to purchased final product and a supervisory authority to perform online inspections on the products’ quality and on the good working practices.
Victor von Wachter, Johannes Rude Jensen, Ferdinand Regner, Omri Ross
The smart contract-based markets for non-fungible tokens (NFTs) on the Ethereum blockchain have seen tremendous growth in 2021, with trading volumes peaking at 3.5b in September 2021. This dramatic surge has led to industry observers questioning the authenticity of on-chain volumes, given the absence of identity requirements and the ease with which agents can control multiple addresses. We examine potentially illicit trading patterns in the NFT markets from January 2018 to mid-November 2021, gathering data from the 52 largest collections by volume. Our findings indicate that within our sample 3.93% of addresses, processing a total of 2.04% of sale transactions, trigger suspicions of market abuse. Flagged transactions contaminate nearly all collections and may have inflated the authentic trading volumes by as much as 149,5m for the period. Most flagged transaction patterns alternate between a few addresses, indicating a predisposition for manual trading. We submit that the results presented here may serve as a viable lower bound estimate for NFT wash trading on Ethereum. Even so, we argue that wash trading may be less common than what industry observers have previously estimated. We contribute to the emerging discourse on the identification and deterrence of market abuse in the cryptocurrency markets.
The paper presents a new digital infrastructure layer for buildings and architectural assets. The infrastructure layer consists of a combination of topology graphs secured on a decentralised ledger. The topology graphs organise non-fungible digital tokens which each represent and correspond to building components, and in the root of the graph to the building itself.The paper presents background research in the relationship of building representation in the form of graphs with topology, of both manifold and non manifold nature. In parallel we present and analyse the relationship between digital representation and physical manifestation of a building, and back again. Within the digital representations the paper analyses the securing and saving of information on decentralised ledger technologies (such as blockchain). We then present a simple sample of generating and registering a non-manifold topology graph on the Ethereum blockchain as an EC721 token, i.e. a digital object that is unique, all through the use of dynamo and python scripting connected with a smart contract on the Ethereum blockchain. Ownership of this token can then be transferred on the blockchain smart contracts. The paper concludes with a discussion of the possibilities that this integration brings in terms of material passports and a circular economy and smart contracts as an infrastructure for whole-lifecycle BIM and digitally encapsulates of value in architectural designPlease write your abstract here by clicking this paragraph.