A Resource-Efficient Smart Contract for Privacy Preserving Smart Home Systems

Blockchain-based solution for COVID-19 vaccine waste reduction

Emergency service call for public service providers has become an important role for smart home applications in order to support safety and security in the household building. Blockchain has been a promising solution with cryptography and incentive distributed mechanisms to support the verification, execution and recording of transactions between untrusted parties. In this paper, we present a Smart Home System (SHS) based on Ethereum with smart contract infrastructure for handling an emergency service sending from SHS to Home Service Providers (HSP) when there are unusual environmental conditions. Our SHS testbed consists of three domains: (1) Smart Home Sensor Manager (SM) or IoT devices to gather environmental sensor data and send an emergency call to HSP, (2) Home Service Provider (HSP) system deployed with Ethereum Virtual Machine (EVM) and smart contract, and (3) decentralize Meteor framework to interface between Ethereum and web based applications for homeowners (HO) and HSP staffs. To achieve homeowner privacy and security, we enable digital signature coupling with InterPlanetary File System (IPFS) for handling the emergency call from SM to HSP and One Time Passcode (OTP) produced by HSP for HSP staffs to verify themselves for further access control when they go to service homeowner’s house. Each smart contract transaction in solidity is described. Finally, security and privacy issues for our proposed work are discussed.

Local energy generation and peer to peer (P2P) energy trading in the local market can reduce energy consumption cost, emission of harmful gases (as renewable energy sources (RESs) are used to generate energy at user's premises) and increase smart grid resilience. In this paper, to implement a hybrid P2P energy trading market, a blockchain-based solution is proposed. A blockchain-based system is fully decentralized and it allows the market members to interact with each other and trade energy without involving any third party. Smart contracts play a very important role in the blockchain-based energy trading market. They contain all the necessary rules for energy trading. We have proposed three smart contracts to implement the hybrid electricity trading market. The market members interact with main smart contract which requests P2P smart contract and prosumer to grid (P2G) smart contract for further processing. The main objectives of this paper are to propose a model to implement an efficient hybrid energy trading market while reducing cost and peak to average ratio (PAR) of electricity.

Smart contracts on the blockchain – A bibliometric analysis and review

As blockchain technology advances, so has the deployment of smart contracts on blockchain platforms, making it exceedingly challenging for users to explicitly identify application services. Unlike traditional contracts, smart contracts are not written in a natural language, making it difficult to determine their provenance. Automatic classification of smart contracts offers blockchain users keyword-based contract queries and a streamlined effective management of smart contracts. In addition, the advancement in smart contracts is accompanied by security challenges, which are generally caused by domain-specific security breaches in smart contract implementation. The development of secure and reliable smart contracts can be extremely challenging due to domain-specific vulnerabilities and constraints associated with various business logics. Accordingly, contract classification based on the application domain and the transaction context offers greater insight into the syntactic and semantic properties of that class. However, despite initial attempts at classifying Ethereum smart contracts, there has been no research on the identification of smart contracts deployed in transactive energy systems for energy exchange purposes. In this article, in response to the widely recognized prospects of blockchain-enabled smart contracts towards an economical and transparent energy sector, we propose a methodology for the detection and analysis of energy smart contracts. First, smart contracts are parsed by transforming code elements into vectors that encapsulate the semantic and syntactic characteristics of each term. This generates a corpus of annotated text as a balanced, representative collection of terms in energy contracts. The use of a domain corpus builder as an embedding layer to annotate energy smart contracts in conjunction with machine learning models results in a classification accuracy of 98.34%. Subsequently, a source code analysis scheme is applied to identified energy contracts to uncover patterns in code segment distribution, predominant adoption of certain functions, and recurring contracts across the Ethereum network.

Purpose The purpose of this study is to address the limitations of traditional methods for managing intellectual property rights (IPRs) by proposing a blockchain-based solution. By leveraging blockchain technology and smart contracts, the aim is to create a comprehensive ecosystem that offers advantages such as reduced transaction costs, improved transparency, enhanced security and increased liquidity levels for IP assets. Design/methodology/approach This paper proposes using blockchain technology to manage intellectual property rights (IPRs) through a smart contract-based ecosystem. It outlines the use of non-fungible tokens (NFTs) on the blockchain to represent IPRs, with smart contracts automating interactions and encoding rules for various processes such as applications, licensing, transfers and royalty distribution. Governance mechanisms, such as decentralized autonomous organizations (DAOs), are employed to allow stakeholders to propose and vote on contract changes, ensuring adaptability. This approach aims to streamline IPR workflows, reduce transaction costs, improve transparency and enhance security. Findings The findings of this study suggest that implementing a blockchain-based ecosystem for managing intellectual property rights (IPRs) can lead to various benefits. These include reduced transaction costs, improved transparency, enhanced security, increased liquidity levels for IP assets and streamlined automated processes. The use of non-fungible tokens (NFTs) on the blockchain allows for detailed management, valuation and trading of IPRs. Furthermore, simulation results demonstrate the robustness and efficiency of our proposed ecosystem, outperforming traditional IP management systems in terms of transaction speed and cost-effectiveness. These simulations highlight the practical viability of integrating blockchain technology into IP management workflows. Practical implications The practical implications of adopting this blockchain-based ecosystem for managing intellectual property rights (IPRs) are significant. By streamlining processes, reducing transaction costs and improving transparency and security, organizations can expedite the protection and commercialization of their IP assets. Additionally, the increased liquidity levels and accessibility of IP assets to investors and financiers can spur innovation and economic growth. Originality/value This paper contributes to the field by proposing a novel approach to managing intellectual property rights (IPRs) using blockchain technology and smart contracts. By leveraging non-fungible tokens (NFTs) on the blockchain, the proposed ecosystem offers a more efficient and transparent way of managing IPRs, reducing reliance on costly and opaque traditional methods. The potential benefits include improved efficiency, transparency, security and collaboration in the management and commercialization of IPRs.

Purpose This paper proposes a blockchain-based solution for high-rise building maintenance and insurance claims, leveraging building information modeling (BIM) data to address limitations of centralized systems, including data integrity, accountability, traceability and reliability in insurance claims processing. Design/methodology/approach A private Ethereum blockchain was integrated with BIM, leveraging smart contracts for maintenance and insurance workflows. The system utilizes the InterPlanetary File System (IPFS) for decentralized storage of large datasets. Key innovations include smart contracts for stakeholder registration, building data management, maintenance agreements, insurance claim processing and reputation management. Findings The proposed system provides decentralized, transparent and traceable management of high-rise building data. By automating workflows through smart contracts, the system enhances data integrity and reduces redundancy in insurance claims. Testing confirmed the smart contracts’ reliability, functionality and capability to streamline operations. Research limitations/implications The system was tested in a simulated environment. Future research could explore scalability, adapting to regulatory frameworks and integrating advanced analytics to address complex maintenance scenarios. Practical implications The system improves accountability in maintenance tasks and simplifies insurance claims by creating immutable, tamper-proof records. Stakeholders can rely on transparent and secure data. Social implications Improved maintenance accountability and transparency in insurance claims enhance the safety and reliability of high-rise buildings, benefiting society at large. Originality/value This study introduces a blockchain-based solution tailored to the unique challenges of high-rise building maintenance and insurance claims, using BIM data to enhance transparency. A novel reputation mechanism is implemented to promote stakeholder accountability, advancing the application of blockchain technology in this context.

Blockchain is a revolutionary technology that is being used in many applications, including supply chain management. The primary goal of using a blockchain for supply chain management is to reduce the overall production cost while providing comprehensive security to the system. However, current blockchain-based supply-chain workflow(s) (BSW) are still susceptible to various cyber threats due to evolving business processes of different stakeholders involved in the process. In fact, current BSW protects the supply chain process based on the rules that have been implemented in the corresponding smart contracts. However, in practice, the requirements for the process keep evolving due to several organizational policies and directives of the involved stakeholders; therefore, current blockchain-based solutions fail to protect the supply chain process against attacks that exploit the process-related information that is not protected by smart contracts. Therefore, the goal of this work was to develop a methodology that enhances the protection of BSW against various internal (e.g., Stuxnet) and external (e.g., local data breach of a stakeholder) cyber threats through monitoring the stakeholder business process. Our methodology complements the blockchain-based solution because it protects the stakeholder’s local process against the attacks that exploit the process information that is not protected in the smart contracts. We implemented a prototype and demonstrated its application to a typical supply chain workflow example application by successfully detecting internal and external attacks to the application.

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.

Fabric is currently the most popular consortium chain platform with a modular architecture that provides high security, elasticity, flexibility and scalability. Smart contracts realize the automatic execution of transactions and the operation of reconciliation data. The Fabric platform supports general programming languages ​​to write smart contracts. However, in the development process of smart contracts, due to insufficient understanding of the underlying operating logic of smart contracts, developers are prone to introduce some risky operations, resulting in a mismatch between the execution logic of smart contracts and business logic, resulting in a lot of losses. The read-after-write risk is a relatively complex and common security risk in smart contracts. Currently, many detection tools cannot detect this risk. There is an urgent need for a solution that can quickly and accurately detect the read-after-write risk in smart contracts. This paper proposes a static analysis smart contract read-after-write risk detection method based on key methods and call chains. The scheme extracts key method patterns on the abstract syntax tree, identifies and locates key methods with risks, greatly reduces the interference of useless nodes on detection, and realizes rapid detection. By constructing the key method call chain, the real call scene is restored according to the call type and attribute of the key method. After experimental verification, compared with the current popular smart contract risk detection tool Revive^CC, the tool proposed in this paper has higher detection accuracy and can more accurately locate the read-after-write risk in smart contracts.

The post-deployment challenges in developing and upgrading blockchain smart contracts necessitate a high level of accuracy in their development and business logic. However, current methodologies for verifying the business logic of smart contracts frequently fail to address their alignment with end-user business requirements. This paper introduces a two-step language transformation process to bridge this gap. Initially, we establish a transformation rule from the Business Process Model and Notation (BPMN) to Prolog, enabling the translation of business processes into a Prolog representation. This step not only validates the business process logic but also ensures it meets user specifications. Subsequently, we introduce a transformation rule from the BPMN to Go, which facilitates the transformation of the BPMN model, once validated, into a Go language smart contract. To enhance usability, we have engineered a dedicated tool that streamlines this transformation process. We present a case study involving a banking loan process to exemplify the utility of our tool in creating BPMN diagrams, conducting requirement and syntax validations, and effecting the transformation to Go smart contracts. The case study and empirical results suggest that our methodology and the accompanying tool mitigate the complexities inherent in smart contract development. They also ensure the fidelity of business logic to user demands, thereby promoting the broader adoption of blockchain smart contract technology.

With the advancement of technology and economy, the scale of the smart home industry has exploded. While improving people’s lives, smart home systems are facing threats to privacy leaks, malicious attacks, and structural security. Effective security mechanisms are very important for protecting valuable data in smart home systems. Access control helps information systems prevent malicious access, thereby reducing the risk of privacy leakage. Blockchain can provide security support for the Internet of Things system due to its advantages of decentralization and immutability. Therefore, in this paper, a smart home access control scheme based on blockchain is proposed. The scheme uses Hyperledger Fabric and implements access control strategies through smart contracts. By designing a hybrid access control model based on dynamic attribute-based access control and static access control matrix, the remote access control initiated by the user through the Internet and the access control between local devices are well guaranteed at the same time. Through safety analysis and performance evaluation, the feasibility of the proposed scheme is demonstrated.

Most of the existing smart-contract-based cryptocurrencies, such as Ethereum, use an account-based ledger. However, while the account-based model is advantageous for the efficient use of smart contracts and the increased exchangeability of cryptocurrencies, it is not well-suited to the parallel execution of smart contracts. However, unspent transaction output (UTXO)-based cryptocurrencies such as Bitcoin are advantageous for parallel cryptocurrency transfers but not well-suited to smart contracts. In this paper, we propose a hierarchical multi-blockchain system that uses multiple pairs of sidechain and dual-sidechains extended by independent block mining in their blockchain networks and a mainchain to control the branching and connection process of sidechains and dual sidechains. In the proposed method, one pair of a sidechain and dual sidechain forms one shard. The proposed method uses multiple shards to execute cryptocurrency transfers and smart contracts in parallel. In addition, the proposed model uses an accoutchain to record the resulting state changes generated by smart contract executions in each shard and securely share them with all other nodes. The proposed method uses a modifiable blockchain structure for the accountchain to obtain the database to record the smart contract execution results in each shard in as small and secure a manner as possible to ensure that all nodes trust the recorded results without executing smart contracts themselves. To examine the validity of the proposed method, we conducted a threat analysis of the proposed method by examining possible attacks in various scenarios as a thought experiment. This threat analysis concludes that the proposed blockchain system can execute smart contracts in parallel while keeping the concurrency in resulting state changes secure.

The age group of 65 years has been described as the fastest growing demographic in the world. As life expectancy increases, older adults prefer to remain independent at home. Smart Home systems and Assistive Technologies have been developed to enable older adults to live in their own homes as they age, enhancing safety, independence and quality of life. Although considerable Smart Home mobile applications exist focused on older adult’s wellbeing, they still face considerable challenges in usability, feasibility and accessibility regarding design of interfaces. There is a gap in recent research on evaluation of User Interface (UI) designed or adapted to address older adults needs and abilities. The paper takes part of an ongoing project evaluation stage, for a smart home and health monitoring system, applied in two stages: (i) heuristic evaluation and (ii) remote user testing. The main objective of the paper is to focus on the second evaluation stage, that took place with end users, applying unmoderated remote usability testing, due to Covid-19 pandemic. According to the System Usability Scale (SUS) and Net Promoter Score (NPS) techniques it could be able to quantify the users experience and measure the level of satisfaction related to the smart home and health monitoring system. The SUS results identified that the system’s usability was considered acceptable with a final score of 65,6. It was concluded that the unmoderated test with a SUS post-questionnaire can be a complex method to apply with older adults. The SUS questionnaire could lead to mistakes and misinterpretation, some contradictory results could be related to this complexity among older adults, and this could lead to a major impact on overall SUS scores. In addition, the NPS metric was identified as not the appropriate to measure user satisfaction with a small sample of users as SUS technique. It is concluded that findings should be supported by applying individual moderated tests with more end users to provide insights to designers and developers to create more usable interfaces to address the needs and abilities of the older adults.KeywordsSmart homeAge-friendly designUser interface designRemote user testing

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