Execution Of Smart Contracts Research Articles

A secure and privacy preserving model for healthcare applications based on blockchain-layered architecture

Blockchain is one of the emerging technologies that are applied in various fields and its application in Healthcare 4.0 is crucial to handle the vast amount of health records that are growing continuously everyday. This paper explores the application of blockchain technology-based layered architecture integrated with Interplanetary File System (IPFS) storage to provide a secure and robust sharing platform for healthcare system. A multilayer security is provided in the proposed system including a 128-bit Random Deoxyribonucleic Acid (DNA) encoding sequence with a modified version of the 128-bit Advanced Encryption Standard (AES) key expansion symmetric key technique is being used before storing the records in the IPFS storage, Rivest–Shamir–Adleman (RSA) 2048 digital envelope is used for secure transmission of symmetric keys, RSA 1024 is used for digital signature, and Secure Hash Algorithm 256-bit (SHA-256) is used for hashing the record files. Comparative analysis with existing state-of-the-art in blockchain-based E-healthcare system is discussed. The performance of various assessment metrics is evaluated, including encryption and decryption time for EHR records, mining time, record retrieval time, smart contract execution time and network latency. Additionally, a reputation-based filtering mechanism specifically designed in the proposed model to detect and mitigate the various attacks.

Designing a secure title deed registration model for land transactions in Kenya based on blockchain

The purpose of this study was to design a secure title deed registration model for land transactions in Kenya based on Blockchain. Blockchain technology creates a publicly accessible distributed database that keeps track of all land transaction records, allowing confirmation of land ownership at any given point in time with the aim of creating a secure and transparent environment that guarantees the much-needed confidentiality and integrity of land transactions. Design Science research methodology was adopted by the research to provide an overall scope in the model design and development requirements, while the Proof of Concept (PoC) research methodology was used to design and develop the essential modules for the model. The research employed subjective sampling to select users to perform a criteria-based model evaluation approach against the evaluation metrics (persistence, time stamping, transparency and decentralisation) set out by the research. Results were presented in the form of a descriptive summary of the users' feedback. From the results, the study established that the model could effectively execute immutable, time-stamped, transparent and decentralised land registration and land transaction processes that can be used as authentic proof of land ownership. The study concluded that the proposed model enhances transparency and security, contributing to a more reliable system that fosters public confidence. The study recommends that future research may focus on the integration of Blockchain with land taxation systems as well as the adoption of cryptocurrency as a legal tender to facilitate the execution of smart contracts for properties in Kenya.

Securing oil port logistics: A blockchain framework for efficient and trustworthy trade documents.

The oil port logistics involves multiple parties including oil tanker owners, port authorities, customs, oil suppliers, and shipping companies. These parties need to exchange a significant amount of data and documentation related to cargo, such as bills of lading, customs declarations, and cargo manifests. This huge amount of data and documentation provides ample opportunities for data manipulation and corruption. Moreover, physical documentation is slow and prone to errors and manipulation. This data can be securely stored and shared between different parties in a tamper-proof and transparent manner using blockchain. Blockchain is a decentralized technology that employs secure hashing and consensus algorithms that can detect any data modification. Hence, this work proposes a blockchain-enabled immutable, and efficient framework for trade documentation in oil port logistics. The proposed framework provides timely processing of oil trade documents and ensures immutability while increasing trust among the trade entities. In addition, this work implements a private blockchain for the execution of smart contracts, which can ensure that all parties involved in the logistics process comply with pre-agreed rules and regulations. Simulation results validate the effectiveness of the proposed framework in terms of transparency, immutability, network latency, throughput, and resource utilization.

Security Analysis of Smart Contract Migration from Ethereum to Arbitrum

When migrating smart contracts from one blockchain platform to another, there are potential security risks. This is because different blockchain platforms have different environments and characteristics for executing smart contracts. The focus of this paper is to study the security risks associated with the migration of smart contracts from Ethereum to Arbitrum. We collected relevant data and analyzed smart contract migration cases to explore the differences between Ethereum and Arbitrum in areas such as Arbitrum cross-chain messaging, block properties, contract address alias, and gas fees. From the 36 types of smart contract migration cases we identified, we selected four typical types of cases and summarized their security risks. The research shows that smart contracts deployed on Ethereum may face certain potential security risks during migration to Arbitrum, mainly due to issues inherent in public blockchain characteristics, such as outdated off-chain data obtained by the inactive sequencer, logic errors based on time, failed permission checks, and denial of service (DOS) attacks. To mitigate these security risks, we proposed avoidance methods and provided considerations for users and developers to ensure a secure migration process. It is worth noting that this study is the first to conduct an in-depth analysis of the secure migration of smart contracts from Ethereum to Arbitrum.

Designing A Blockchain-Empowered Telehealth Artifact for Decentralized Identity Management and Trustworthy Communication: Interdisciplinary Approach.

Telehealth played a critical role during the COVID-19 pandemic and continues to function as an essential component of health care. Existing platforms cannot ensure privacy and prevent cyberattacks. The main objectives of this study are to understand existing cybersecurity issues in identity management and trustworthy communication processes in telehealth platforms and to design a software architecture integrated with blockchain to improve security and trustworthiness with acceptable performance. We improved personal information security in existing telehealth platforms by adopting an innovative interdisciplinary approach combining design science, social science, and computer science in the health care domain, with prototype implementation. We used the design science research methodology to implement our overall design. We innovated over existing telehealth platforms with blockchain integration that improves health care delivery services in terms of security, privacy, and efficiency. We adopted a user-centric design approach and started with user requirement collection, followed by system functionality development. Overall system implementation facilitates user requirements, thus promoting user behavior for the adoption of the telehealth platform with decentralized identity management and an access control mechanism. Our investigation identified key challenges to identity management and trustworthy communication processes in telehealth platforms used in the current health care domain. By adopting distributed ledger technology, we proposed a decentralized telehealth platform to support identity management and a trustworthy communication process. Our design and prototype implementation using a smart contract-driven telehealth platform to provide decentralized identity management and trustworthy communication with token-based access control addressed several security challenges. This was substantiated by testing with 10,000 simulated transactions across 5 peers in the Rahasak blockchain network. The proposed design provides resistance to common attacks while maintaining a linear time overhead, demonstrating improved security and efficiency in telehealth services. We evaluated the performance in terms of transaction throughput, smart contract execution time, and block generation time. To create a block with 10,000 transactions, it takes 8 seconds on average, which is an acceptable overhead for blockchain-based applications. We identified technical limitations in current telehealth platforms. We presented several design innovations using blockchain to prototype a system. We also presented the implementation details of a unique distributed architecture for a trustworthy communication system. We illustrated how this design can overcome privacy, security, and scalability limitations. Moreover, we illustrated how improving these factors sets the stage for improving and standardizing the application and for the wide adoption of blockchain-enabled telehealth platforms.

Smart Transportation Systems: IOT-enabled Traffic Management & Vehicle-to-infrastructure Communication

Recently, there has been a substantial increase in the number of cars on the road. Escalating traffic congestion is a widespread problem that folks face on a daily basis. The manual control of traffic-by-traffic police has shown to be ineffective. “Furthermore, the signal's set duration has failed to effectively address this issue, regardless of the level of traffic congestion. This research presents a communication system called Vehicle-to-Blockchain (V2B), which utilizes blockchain technology to enable transparent and decentralized communications. The aim is to optimize the incorporation of blockchain technology into V2X (Vehicle-to-Everything) and IoT (Internet of Things) systems, therefore enhancing the efficiency and effectiveness of future transportation systems. We present a range of advanced applications for blockchain technology, such as a car ownership system that utilizes the multi-token standard, a vehicle grading system, the integration of blockchain with the Internet of Things (IoT), and a decentralized ticket administration system for transportation services. The design places a high emphasis on essential elements such as the seamless integration of data, precise precision, and the establishment of secure connections. Furthermore, it includes a decentralized payment system and marketplace for transportation inside smart cities. Our main focus is on the technical execution of smart contracts in these particular scenarios, highlighting their importance in guaranteeing strong and dependable interactions. Our decentralized approach creates a transportation ecosystem that has the ability to adjust and fulfill the evolving requirements of intelligent urban areas. It is groundbreaking, durable, and capable

An efficient certificateless blockchain-enabled authentication scheme to secure producer mobility in named data networks

Named Data Networking (NDN) aims to establish an efficient content delivery architecture. In NDN, secure and effective identity authentication schemes ensure secure communication between producers and routers. Currently, there is no feasible solution to perform identity authentication of mobile producers in NDNs. Identity authentication schemes in other networks are either weak in security or performance, such as privacy leakage, difficulty to establish cross-domain trust, and long handover delays, and are not fully adaptable to the security requirements of NDNs. Additionally, the mobility of producers was not fully considered in the initial design of NDNs. This paper first revises the structure of packets and routers to support the identity authentication and mobility of producers. On this basis, this paper proposes a secure and efficient certificateless ECC-based producer identity authentication scheme (CL-BPA), which includes initial authentication and re-authentication, aimed at achieving rapid switch authentication and integrating blockchain to solve single-point failure issues. Using the Canetti and Krawczyk (CK) adversarial model and informal security analysis, the proposed CL-BPA scheme is demonstrated to be resistant to anonymity attacks, identity forgery attacks, and man-in-the-middle attacks. The performance analysis demonstrates that the proposed CL-BPA scheme exhibits excellent capabilities in terms of computation delay, communication cost, smart contract execution time, average response delay, and throughput.

A Blockchain and PKI-Based Secure Vehicle-to-Vehicle Energy-Trading Protocol

With the increasing awareness for sustainable future and green energy, the demand for electric vehicles (EVs) is growing rapidly, thus placing immense pressure on the energy grid. To alleviate this, local trading between EVs should be encouraged. In this paper, we propose a blockchain and public key infrastructure (PKI)-based secure vehicle-to-vehicle (V2V) energy-trading protocol. A permissioned blockchain utilizing the proof of authority (PoA) consensus and smart contracts is used to securely store data. Encrypted communication is ensured through transport layer security (TLS), with PKI managing the necessary digital certificates and keys. A multi-leader, multi-follower Stackelberg game-based trade algorithm is formulated to determine the optimal energy demands, supplies, and prices. Finally, we propose a detailed communication protocol that ties all the components together, enabling smooth interaction between them. Key findings, such as system behavior and performance, scalability of the trade algorithm and the blockchain, smart contract execution costs, etc., are presented through numerical results by implementing and simulating the protocol in various scenarios. This work not only enhances local energy trading among EVs, encouraging efficient energy usage and reducing burden on the power grid, but also paves a way for future research in sustainable energy management.

A Local-First Approach for Green Smart Contracts

Shared code in blockchains, known as smart contracts , stands to replace important parts of our digital governance and financial infrastructure. The permissionless execution of smart contracts is tightly coupled to cryptocurrencies and Proof-of-Work blockchains. As a result, smart contracts inherit the environmental impact of Proof-of-Work blockchains, such as its energy consumption, carbon footprint, and electronic waste. The four concepts of relaxed consistency, strong identities, probabilistic consensus, and the use of liabilities instead of assets may change the status quo. This work explores the integration of these concepts to decouple smart contracts from Proof-of-Work blockchains. By means of a local-first approach, which may expose users to inconsistent ephemeral contract states, the architecture of smart contracts can be transformed to become green. Because such contract states may be dropped, we base the interactions between users on liabilities. We propose a novel paradigm for smart contract architectures, named Green Smart Contracts, that is based on a local-first approach. Furthermore, we present and implement a prototype solution for this paradigm. We validate the need for a mechanism to resolve consistency violations by replaying the contract calls of a real smart contract. Our simulation shows that violations occur more often (13% of contract invocations) when using liabilities than when using a traditional blockchain (3% of contract invocations). However, we additionally validate that they can be avoided using a consensus mechanism, and our experiments show that a publish-subscribe messaging pattern uses the fewest messages to do so, though it may not be applicable for use cases that disallow the inherent imbalance in the messaging between peers. Our carbon emission estimation shows that a Green Smart Contract approach lowers carbon emissions by 52.31% when compared with the messaging behavior of a typical peer-to-peer blockchain with 1000 nodes.

DSCAPS: A decentralized smart contract auditing platform based on sidechain

Successful attacks on smart contracts can result in loss of digital assets with potential financial and reputation implications. This reinforces the importance of auditing smart contracts prior to deployment. However, existing auditing approaches are generally non transparent, inefficient, limited to known bugs, and imprecise due to lack of real-world information in the blockchain. Therefore, we design a Decentralized Smart Contract Auditing Platform based on Sidechain (DSCAPS) in this paper. DSCAPS leverages the two-way peg sidechain technology to implement the interactions between the main chain and the sidechain which is used as the audit chain platform. Unlike conventional centralized audits, blockchain users can evaluate the security of contracts in a real-world smart contract execution environment by designing an appropriate incentive mechanism. Thus, detection results will be more comprehensive and precise. Moreover, to prevent multi-party collusion from manipulating the blockchain or audit process, we introduce a margin mechanism. Findings from our security analysis demonstrate that DSCAPS can mitigate potential threats. Evaluation findings based on the system implementation also show that DSCAPS is efficient in auditing a contract with performance overheads of less than 10%.

Blockchain Revolution in Asset Management: A Comprehensive Analysis and Implementation Framework

A project that presents the harnesses blockchain technology to develop a Token Asset Management System (TAMS) aimed at revolutionizing conventional asset management practices. TAMS leverages the decentralized and transparent nature of blockchain to create digital tokens representing ownership or rights to various assets. These tokens enable fractional ownership, streamlined trading, and automated execution of smart contracts for dividends and voting. The project's primary objectives are to enhance efficiency, security, and transparency in asset management. By digitizing assets and recording transactions on an immutable ledger, TAMS reduces the need for intermediaries, minimizes administrative costs, and ensures auditability. Smart contracts automate key processes, improving accuracy and trust among participants. The project's implementation involves selecting an appropriate blockchain platform, designing token standards, creating an intuitive user interface, and adhering to regulatory requirements. The potential challenges of scalability and legal compliance are also considered. In summary, the Token Asset Management project exemplifies blockchain's potential to transform asset management. Through tokenization and blockchain's features, TAMS aims to establish a modernized ecosystem that offers efficient, secure, and transparent asset management solutions.

Spectrum: Speedy and Strictly-Deterministic Smart Contract Transactions for Blockchain Ledgers

Today, blockchain ledgers utilize concurrent deterministic execution schemes to scale up. However, ordering fairness is not preserved in these schemes: although they ensure all replicas achieve the same serial order, this order does not always align with the fair, consensus-established order when executing smart contracts with runtime-determined accesses. To preserve ordering fairness, an intuitive method is to concurrently execute transactions and re-execute any order-violating ones. This in turn increases unforeseen conflicts, leading to scaling bottlenecks caused by numerous costly aborts under contention. To address these issues, we propose Spectrum, a novel deterministic execution scheme for smart contract execution on blockchain ledgers. Spectrum preserves the consensus-established serial order (so-called strict determinism) with high performance. Specifically, we leverage a speculative deterministic concurrency control to execute transactions in speculation and enforce an agreed-upon serial order by aborting and re-executing any mis-speculated ones. To overcome the scaling bottleneck, we present two key optimizations based on speculative processing: operation-level rollback and predictive scheduling, for reducing both the overhead and the number of mis-speculations. We evaluate Spectrum by executing EVM-based smart contracts on popular benchmarks, showing that it realizes fair smart contract execution by preserving ordering fairness and outperforms competitive schemes in contended workloads by 1.4x to 4.1x.

ChainAgile: A framework for the improvement of Scrum Agile distributed software development based on blockchain.

Software Development based on Scrum Agile in a distributed development environment plays a pivotal role in the contemporary software industry by facilitating software development across geographic boundaries. However, in the past different frameworks utilized to address the challenges like communication and collaboration in scrum agile distributed software development (SADSD) were notably inadequate in transparency, security, traceability, geographically dispersed location work agreements, geographically dispersed teamwork effectiveness, and trust. These deficiencies frequently resulted in delays in software development and deployment, customer dissatisfaction, canceled agreements, project failures, and disputes over payments between customers and development teams. To address these challenges of SADSD, this paper proposes a new framework called ChainAgile, which leverages blockchain technology. ChainAgile employs a private Ethereum blockchain to facilitate the execution of smart contracts. These smart contracts cover a range of functions, including acceptance testing, secure payments, requirement verification, task prioritization, sprint backlog, user story design and development and payments with the automated distribution of payments via digital wallets to development teams. Moreover, in the ChainAgile framework, smart contracts also play a pivotal role in automatically imposing penalties on customers for making late payments or for no payments and penalties on developers for completing the tasks that exceed their deadlines. Furthermore, ChainAgile effectively addresses the scalability limitations intrinsic in blockchain technology by incorporating the Interplanetary File System (IPFS) is used for storage solutions as an off-chain mechanism. The experimental results conclusively show that this innovative approach substantially improves transparency, traceability, coordination, communication, security, and trust for both customers and developers engaged in scrum agile distributed software development (SADSD).

VM Matters: A Comparison of WASM VMs and EVMs in the Performance of Blockchain Smart Contracts

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.

Blockchain-secure patient Digital Twin in healthcare using smart contracts.

Modern healthcare has a sharp focus on data aggregation and processing technologies. Consequently, from a data perspective, a patient may be regarded as a timestamped list of medical conditions and their corresponding corrective interventions. Technologies to securely aggregate and access data for individual patients in the quest for precision medicine have led to the adoption of Digital Twins in healthcare. Digital Twins are used in manufacturing and engineering to produce digital models of physical objects that capture the essence of device operation to enable and drive optimization. Thus, a patient's Digital Twin can significantly improve health data sharing. However, creating the Digital Twin from multiple data sources, such as the patient's electronic medical records (EMR) and personal health records (PHR) from wearable devices, presents some risks to the security of the model and the patient. The constituent data for the Digital Twin should be accessible only with permission from relevant entities and thus requires authentication, privacy, and provable provenance. This paper proposes a blockchain-secure patient Digital Twin that relies on smart contracts to automate the updating and communication processes that maintain the Digital Twin. The smart contracts govern the response the Digital Twin provides when queried, based on policies created for each patient. We highlight four research points: access control, interaction, privacy, and security of the Digital Twin and we evaluate the Digital Twin in terms of latency in the network, smart contract execution times, and data storage costs.

Healthcare System Using Blockchain

The global Electronic Health Record (EHR) market is growing dramatically and is expected to reach $39.7 billion by 2022. To safeguard the security and privacy of EHR, access control is an essential mechanism for managing EHR data. This paper proposes a hybrid architecture to facilitate access control of EHR data by using both blockchain and edge nodes. Within the architecture, a blockchain-based controller manages identity and access control policies and serves as a tamper-proof log of access events. In addition, off-chain edge nodes store the EHR data and apply policies specified in Abbreviated Language For Authorization (ALFA) to enforce attribute-based access control on EHR data in collaboration with the blockchain-based access control logs. We evaluate the proposed hybrid architecture by utilizing the Hyperledger Composer Fabric blockchain to measure the performance of executing smart contracts and ACL policies in terms of transaction processing time and response time against unauthorized data retrieval. Keywords:Attribute-based Access Control, Access Control List, Blockchain, Edge Computing, Hyperledger, Smart Contract

Blockchain for the Energy Transition

The massive impact of the wind and PhotoVoltaic (PV) power on the power systems require new approach and strategies, because of their unpredictability. This large expansion has been due to the feed-in tariffs, financial support and a concentration of R&D activities. Moreover, the distributed energy sources require a pervasive and complex management of the energy exchanges. Until now, the management has been usually based on a central authority, but new paradigms based on the BlockChain (BC) technology are very promising. This approach can also be useful to manage the peak power as well as the Demand-Response (DR) strategies. The paper presents this challenging tool for the current energy transition, highlighting the intrinsic features of the blockchain technology and the opportunities for the future energy systems, e.g. the execution of smart contracts in Peer-to-Peer (P2P) networks. This approach will become increasingly useful to manage the energy exchanges in new contexts, where the number of prosumers and active users is growing. The paper also proposes an application of the BC to manage the peak demand, using the energy injected into the grid by the electric vehicles.

Time-Varying Bidirectional Causal Relationships between Transaction Fees and Economic Activity of Subsystems Utilizing the Ethereum Blockchain Network

The Ethereum blockchain network enables transaction processing and smart-contract execution through levies of transaction fees, commonly known as gas fees. This framework mediates economic participation via a market-based mechanism for gas fees, permitting users to offer higher gas fees to expedite processing. Historically, the ensuing gas fee volatility led to critical disequilibria between supply and demand for block space, presenting stakeholder challenges. This study examines the dynamic causal interplay between transaction fees and economic subsystems leveraging the network. By utilizing data related to unique active wallets and transaction volume of each subsystem and applying time-varying Granger causality analysis, we reveal temporal heterogeneity in causal relationships between economic activity and transaction fees across all subsystems. This includes (a) a bidirectional causal feedback loop between cross-blockchain bridge user activity and transaction fees, which diminishes over time, potentially signaling user migration; (b) a bidirectional relationship between centralized cryptocurrency exchange deposit and withdrawal transaction volume and fees, indicative of increased competition for block space; (c) decentralized exchange volumes causally influence fees, while fees causally influence user activity, although this relationship is weakening, potentially due to the diminished significance of decentralized finance; (d) intermittent causal relationships with maximal extractable value bots; (e) fees causally influence non-fungible token transaction volumes; and (f) a highly significant and growing causal influence of transaction fees on stablecoin activity and transaction volumes highlight its prominence. These results inform strategic considerations for stakeholders to more effectively plan, utilize, and advocate for economic activities on Ethereum, enhancing the understanding and optimization of within the rapidly evolving economy.

ASBlock:An Agricultural based Supply Chain Management using Blockchain Technology

Blockchain is a distributed digital ledger technology that allows for the immutable and auditable logging of transactions without needing a central authority or centralized database. First introduced in 2008 as the technology behind the digital currency Bitcoin, blockchain has now found use in a wide range of sectors. Modern agriculture supply networks have emerged to accommodate intricate interactions between regional actors and the agricultural environment. Interactions between various participants in the supply chain, including those involved in manufacturing, processing, and delivery. One of the main reasons fraud happens so often in agriculture is the lack of transparency in the supply chain. Businesses that aren’t transparent run the risk of losing money, alienating their customers, and seeing their brands decline in value. To encourage the growth of an efficient and trustworthy trading environment, several fundamental adjustments to the current supply chain architecture are necessary. The potential for blockchain technology to enhance food and agricultural supply chain transparency is well acknowledged. Companies utilize IoT and blockchain to create more equitable, sustainable, and customer-friendly food manufacturing systems. In this current work, a blockchain-based decentralized application (dApp), ‘ASBlock’, is developed for agricultural-based supply chain management. The primary focus of this developed application is to bring transparency and security to all participating users of the application; the users of this application include farmers or producers, suppliers or retailers, hotels, and end users. The performance analysis shows that the average gas utilization of the proposed ASBlock dApp is ∼ 2.8 ⋆ 104. The average smart contract execution time for all use cases is ∼ 112sec.

PaVM: A Parallel Virtual Machine for Smart Contract Execution and Validation

PaVM: A Parallel Virtual Machine for Smart Contract Execution and Validation