Blockchain-Enabled Smart Contracts: Architecture, Applications, and Future Trends

Electronic prescription (e-Prescription) is a digital way to manage medical prescriptions and reduce inconsistencies in the communication between doctors, patients, and pharmacies. Smart contracts allow the automation of tasks and business rules in a decentralized architecture (i.e., without the need for an intermediary or central authority). Platforms such as Ethereum and Hyperledger Fabric support smart contracts development through a consensus mechanism such as Proof-of-Work or another criterion among the network's participating nodes. This paper explores Tendermint, a Byzantine Fault Tolerant (BFT) based consensus mechanism that has not yet been widely adopted for smart contracts platforms. We apply our devised model to the healthcare application domain, more precisely in the field of e-prescription, and our results demonstrate that smart contracts can be implemented on a BFT-based platform. To the best of our knowledge, this is the first study investigating the implementation of smart contracts in a BFT-based platform such as Tendermint. We exploit this domain as there can exist some conflicting interests of profit-taking. For example, pharmacists can increase the medication dosage above the one prescribed by doctors for profit-taking. Such a scenario can occur particularly in countries where healthcare is free of charge and offered as a public service (e.g., Brazil). We show that smart contracts in BFT-based blockchain can help in solving problems in these application scenarios. Finally, our two key contributions in this paper are two-fold: (i) exploit smart-contracts in BFT-based platforms where they (smart contracts) are not very established yet in the blockchain domain; (ii) provide a smart-contract-based e-prescription solution to reduce the costs (no need for a central authority) and scams particularly in countries where the medical service is free and public.

iContractML 2.0: A domain-specific language for modeling and deploying smart contracts onto multiple blockchain platforms

The rapid advancement of the Internet of Things (IoT) is reshaping industries by enabling seamless communication between devices, real-time data collection, and automation. Given the surge in IoT applications, challenges related to security, scalability, and interoperability have become increasingly critical. This study presents a state-of-the-art software engineering framework designed to address these limitations through the integration of blockchain technology and smart contracts. By leveraging the decentralized, immutable, and transparent nature of blockchain, the proposed framework enhances trust and security within IoT environments. Smart contracts, as secure, self-executing code, facilitate autonomous interactions between IoT devices without relying on centralized control. Additionally, the framework introduces novel strategies for optimizing resource management and data handling efficiency while improving system scalability across distributed networks. The synergistic use of blockchain and smart contracts not only resolves key IoT challenges but also contributes to the development of robust, efficient, and scalable IoT ecosystems. The framework is applicable across diverse domains, including healthcare, smart cities, supply chain management, and industrial automation, fostering innovative, self-governing IoT systems throughout their operational lifecycle.

Blockchain is an emerging technology with broad applications. As an important application of the blockchain, smart contracts can formulate trading rules to manage thousands of virtual currencies. Nowadays, the IoT (Internet of Things) combined with blockchain has become a new trend and smart contract can implement different transaction demands for IoT-blockchain systems. Once there exits vulnerability in the smart contract program, the security of the virtual currency will not be guaranteed. However, ensuring the security of smart contracts is never an easy task. On the one hand, existing smart contracts cannot identify fake users or malicious programs, which is difficult to be regulated at present; on the other hand, smart contracts involving in multiple trading users are very similar to shared-memory concurrent programs. To deal with these problems, this study uses formal verification methods, adopting the Communicating Sequence Processes (CSP) theory to formally model concurrent programs. Then the FDR (Failure Divergence Refinement), a refinement checker or model checker for CSP, is utilized to successfully detect the vulnerability regarding concurrency in one smart contract public in Ethereum. The results show the potential advantage of using CSP and FDR tool to check the vulnerability in smart contracts especially from the perspective of concurrency.

Recently, with the popularity of Internet of vehicles (IoV), there is an increasing market demand for integrating blockchain technology and smart contracts in electric vehicles. By utilizing distributed blockchain and smart contract technology, it provides data integrity preservation, traceability, and prevention of forgery. These features can be effectively used in the automated charging system. As a result, IoV can utilize blockchain and smart contract technologies to facilitate seamless payment for charging fees, tolls, parking fees, online shopping and other associated expenses without the need for intermediaries. However, since blockchain and smart contracts operate in an open internet environment, there is a risk of tampering with transaction records. Therefore, enhancing security becomes a crucial concern. The main aim of this study is to emphasize the growing significance of securing transactions and smart contracts in an open transmission environment to prevent potential damage or alteration.In order to achieve the implementation of secure smart contracts within a resource-constrained IoV, this study investigates various cryptographic mechanisms and realizes the elliptic curve cryptosystem (ECC) is widely recognized for providing strong security with shorter key lengths compared to other public key cryptography methods. This makes it ideal for environments with limited resources. Furthermore, in order to enhance the performance of smart contracts, this study proposes a cloud server architecture for parallel storage of smart contracts to improve access speed. Additionally, we introduce an automated trading framework for smart contracts that operates without human intervention.Finally, this study uses ECC to ensure the secure transmission of transaction data among the vehicle, base station, and cloud server, as well as to provide mutual verification of identities across all entities involved in the operation. As a result, this study proposes a secure architecture for blockchain and smart contracts that can autonomously initiate transactions while ensuring secure transmission and protection in the IoV.

The Internet of Things (IoT) is a network of sensors that helps collect data 24/7 without human intervention. However, the network may suffer from problems such as the low battery, heterogeneity, and connectivity issues due to the lack of standards. Even though these problems can cause several performance hiccups, security issues need immediate attention because hackers access vital personal and financial information and then misuse it. These security issues can allow hackers to hijack IoT devices and then use them to establish a Botnet to launch a Distributed Denial of Service (DDoS) attack. Blockchain technology can provide security to IoT devices by providing secure authentication using public keys. Similarly, Smart Contracts (SCs) can improve the performance of the IoT–blockchain network through automation. However, surveyed work shows that the blockchain and SCs do not provide foolproof security; sometimes, attackers defeat these security mechanisms and initiate DDoS attacks. Thus, developers and security software engineers must be aware of different techniques to detect DDoS attacks. In this survey paper, we highlight different techniques to detect DDoS attacks. The novelty of our work is to classify the DDoS detection techniques according to blockchain technology. As a result, researchers can enhance their systems by using blockchain-based support for detecting threats. In addition, we provide general information about the studied systems and their workings. However, we cannot neglect the recent surveys. To that end, we compare the state-of-the-art DDoS surveys based on their data collection techniques and the discussed DDoS attacks on the IoT subsystems. The study of different IoT subsystems tells us that DDoS attacks also impact other computing systems, such as SCs, networking devices, and power grids. Hence, our work briefly describes DDoS attacks and their impacts on the above subsystems and IoT. For instance, due to DDoS attacks, the targeted computing systems suffer delays which cause tremendous financial and utility losses to the subscribers. Hence, we discuss the impacts of DDoS attacks in the context of associated systems. Finally, we discuss Machine-Learning algorithms, performance metrics, and the underlying technology of IoT systems so that the readers can grasp the detection techniques and the attack vectors. Moreover, associated systems such as Software-Defined Networking (SDN) and Field-Programmable Gate Arrays (FPGA) are a source of good security enhancement for IoT Networks. Thus, we include a detailed discussion of future development encompassing all major IoT subsystems.

In these years, Blockchain technology is growing in importance thanks to cryptocurrencies. This technology offers many features such as the immutability of data stored in the data chain, the replicability of data in nodes, the management without a central repository, etc. These features are widely adopted also in other fields such as in distributed measurement systems. Although the Blockchain technology is widespread worldwide, there is still a legislative gap in the adoption of this technology in various states. This paper will examine the challenge and future trends on distributed measurement systems based on Blockchain technology in the European context. In particular, critical aspects of Blockchain technology will be examined under GDPR point of view and in particular in the management of data and privacy. The advantages and disadvantages of using Blockchain technology in applications such as the Internet of Things and smart contracts will be discussed and some aspects of legal metrology in Blockchain networks will be analyzed. At the end, future trends in Blockchain technology applied to distributed measurement systems will be shown.

Despite their promising potential, the level of implementation of smart contracts is not at the desired level. To expedite the acceptance and deployment of smart contracts, the barriers to the implementation of smart contracts should be revealed. Past studies, however, do not provide a comprehensive theoretical basis due to several methodological drawbacks. Thus, this study aims to identify and assess the barriers to the implementation of smart contracts by considering the inherent characteristics of the construction industry. An in-depth literature review was initially conducted to extract all barriers proposed in the literature. Then, focus group discussion (FGD) sessions were conducted with the participation of the construction practitioners. In the FGD session, the results of the literature review were validated, and nine additional barriers were proposed. Finally, a total of 20 barriers under five categories was proposed for the smart contract adoption in the construction industry. Then, a questionnaire survey was conducted with the participation of 15 construction practitioners. Lastly, fuzzy VIKOR analysis was performed to assess the criticality of the implementation barriers. This study indicates that the construction companies should overcome not only technical barriers but also managerial barriers. Changes in the processes arisen due to smart contract implementation prevent the construction from implementing a smart contract, since the employees show resistance to these changes. Furthermore, the companies believe that they can lose their bargaining power with smart contracts, and they do not want to lose their power. Bottlenecks are considered the most critical barrier from a technological perspective, and companies are concerned about the problems resulting from them. Although this study provides insights into the barriers to smart contracts in the construction industry, all the respondents are from Turkey. Therefore, some of the findings of this study can be specific to the Turkish construction industry.

The convergence of the Internet of Things (IoT), fog computing, and block chain technology has revolutionized contemporary digital ecosystems by making data management decentralized, efficient, and scalable. Nonetheless, this integration poses serious security and privacy threats. IoT devices produce enormous amounts of sensitive data, making them easy targets for cyber attacks, unauthorized access, and data breaches. Classic cloud-based solutions tend to be challenged by latency, bandwidth limitations, and centralized attacks, making the use of fog computing inevitable to decentralize data processing for better responsiveness and decreased dependency on remote cloud servers. While fog computing offers advantages, it also poses new security threats through possible insider attacks and data integrity issues. Block chain technology solves these problems by presenting a tamper-resistant, decentralized ledger that improves trust, security, and transparency for IoT networks. Block chain, via cryptographic authentication, consensus protocols, and smart contracts, ensures the secure transaction of data while alleviating risks against unauthorized data manipulation. Scalability, computational complexity, and energy efficiency are still challenges that need to be met for widespread IoT adoption. This chapter discusses the complex security and privacy problems in IoT, fog, and blockchain networks and examines current threats and countermeasures. Advanced cryptographic methods, secure communication schemes, and access control techniques for strengthening the security of these connected systems are mentioned. It further presents future research directions and trends that will improve a safer, more efficient, and privacy-augmented digital infrastructure.

PurposeCross border trade, involving different business environments between the sellers’ and buyers’ countries, may result in conflicts because of asymmetry in the information structure across the borders. The International Chambers of Commerce (ICC) has laid down ground rules on terms of shipment and payment, enabling harmonization and standardization of business process, and fixing of responsibilities for international trade. The international commercial (INCO) terms by ICC define the duties, obligations and cost borne by the exporter and the importer. An exporter’s uncertainty looms once the goods cross his/her border. Therefore, there is a need for a smart contract that is secured, transparent, legitimate and trustworthy. The authors propose a blockchain technology-based smart global contract (BTGC) framework for international trade.Design/methodology/approachIn this paper, the authors develop the framework based on value chain analysis (VCA) of international trade and an ontology-driven-blockchain-design approach. The paper analyzes the sequence of activities in the value chain of global trade, the terms of the contract, the data structure templates, the validation rules and the points-of-failure, and proposes the smart contract blockchain structure.FindingsThis paper proposes the BTGC framework considering the INCO terms 2020; it provides the validation rules and the probability of failures; and identifies the elements that cause the halting of contracts and conditions of creation of side blockchains. The framework also includes the governance of the BTGC system.Research limitations/implicationsThe proposed framework not only has implications at the firm level as it automates and secures a global sale contract but also is expected to harmonize the global-trade process as well. The developers may use the attributes, data structure templates and the rules identified in this paper for developing the GC software. Future research may consider using case analysis, class diagrams and the related steps for developing the blockchain software.Originality/valueThis paper proposes a complete value chain of global contract (GC) concerning exports, an ontology of GC and a blockchain-based smart-contract framework based on global standards. Besides, it specifies the elements of fraud (such as the non-integration of side chains) and uncertainty, i.e. the probability of failures. Such a framework will harmonize the global-trade process and build an international standards for smart GC based on blockchain technology (ISSGCBT), which is not yet done.

The popularity of blockchain is on the rise as the technology is touted to become an enabler of many existing and futuristic applications. These applications range from cryptocurrency-based financial applications to secure supply chain management, privacy-protected medical data handling, secure yet transparent e-voting, decentralized Internet of Things (IoT), and fault-tolerant Unmanned Aerial Vehicles (UAVs) towards future 6G communication networks. There are numerous inherent features of blockchain that drive these applications, such as transparency, decentralization, non-repudiation, immutability, pseudonymity, provenance, and lower operational costs. Moreover, the smart contracts further enhance the capabilities of blockchain. Thus, this chapter aims to provide an in-depth understanding of blockchain and smart contracts. In particular, the chapter begins by introducing blockchain as one of the most popular types of Distributed Ledger Technology (DLT). Subsequently, the block structure, transaction process flow, salient features, and the different types of blockchain are presented. Next, the concept of smart contract is discussed along with its salient features and the different blockchain platforms that support smart contracts. Furthermore, the chapter introduces various growing applications of blockchain. Finally, the security aspects of blockchain and smart contracts are briefly discussed since it is an evolving technology.

The inception of blockchain techniques has been revolutionizing various domains, e.g., Internet of Things, supply chain and healthcare. Ethereum smart contracts emerge as the promising blockchain application, which could enable distrustful parties to participate in the automatic and trustful transactions. Given the increasing importance of Ethereum smart contracts, understanding them becomes imperative. However, prior work only studied smart contracts with general high-level patterns, and one critical question has not been answered yet: how do smart contracts behave individually? In this paper, we present a behavior-aware profiling of individual smart contract from a multi-party perspective, which improves the visibility of the smart contract ecosystem. We conduct a detailed study of the behavior of individual smart contract on two real-world datasets, and our profiling reveals interesting and surprising observations. For example, a few contract completion chains have more than 50 contracts and all of them belong to the Finance category. We also discuss the implications that lead to recommendations to improve the security and performance of the smart contract ecosystem. Overall, our work effectively complements previous work towards generating a comprehensive understanding of smart contracts.

The article examines methods and information technologies aimed at ensuring the secure integration of the Ethereum blockchain with Internet of Things (IoT) systems. The relevance of the study is driven by the rapid development of IoT, which is accompanied by increasing cybersecurity threats, including unauthorized data access, man-in-the-middle (MITM) attacks, device identifier spoofing, and the low transparency of centralized systems. The use of Ethereum blockchain technology, particularly smart contracts, opens new opportunities for creating decentralized security management models for IoT devices, enhancing trust levels, automating processes, and minimizing third-party interference risks. The “Problem statement” section outlines the key challenges in securing IoT networks, including the vulnerabilities of centralized solutions, limited computational resources of devices, and the need to develop autonomous access control systems. The “Analysis of Recent Research and Publications” section summarizes modern approaches to integrating Ethereum blockchain into the IoT field, including tokenized identification mechanisms, access control, and transaction processing using smart contracts. It is noted that leading researchers suggest Layer-2 solutions (state channels, zk-rollups, Plasma) aimed at reducing the load on the main blockchain and improving scalability. The aim of the article is to systematize modern methods of integrating the Ethereum blockchain with IoT and develop recommendations for their implementation, considering the limited resources of devices. The “Research results” section presents a secure IoT system architecture concept based on decentralized account management, local storage of cryptographic keys on devices, the use of optimized transaction signing algorithms, and the introduction of a hybrid data storage model based on IPFS. The proposed model minimizes the risk of unauthorized access, increases transparency in the interaction between IoT devices, and reduces computational resource costs. The “Conclusions and prospects for further research” section emphasizes that the implementation of the Ethereum blockchain in IoT promotes the development of secure decentralized platforms. However, it requires addressing issues such as energy consumption, transaction costs, and optimizing client applications for low-performance devices. Future research should focus on developing effective scalability tools, adapting smart contracts to IoT specifics, and improving integration with cloud computing platforms for storing large data sets.

In collaborative environments, where enterprises interact each other’s without a centralised authority that ensures trust among them, the ability of providing cross-organisational services must be enabled also between mutually untrusting participants. Blockchain platforms and smart contracts have been proposed to implement collaborative processes. However, current solutions are platform-dependent and deploy on-chain the whole process, thus increasing the execution costs of smart contracts if deployed on permissionless blockchain. In this paper, we propose an approach that includes criteria to identify trust-demanding objects and activities in collaborative processes, a model to describe smart contracts in a platform-independent way and guidelines to deploy them in a blockchain. To this aim, a three-layered model is used to describe: (i) the collaborative process, represented in BPMN, where the business expert is supported to add annotations that identify trust-demanding objects and activities; (ii) Abstract Smart Contracts based on trust-demanding objects and activities only and specified by means of descriptors, that are independent from any blockchain technology; (iii) Concrete Smart Contracts, that implement abstract ones and are deployed over a specific blockchain, enabling the creation of a repository where a single descriptor is associated with multiple implementations. The flexibility and reduced costs of the approach, due to the smart contracts abstraction and the use of blockchain only when necessary, are discussed with a case study on remote monitoring services in the digital factory.

In recent years, the rapid development of blockchain technology and cryptocurrencies has influenced the financial industry by creating a new crypto-economy. Then, next-generation decentralized applications without involving a trusted third-party have emerged thanks to the appearance of smart contracts, which are computer protocols designed to facilitate, verify, and enforce automatically the negotiation and agreement among multiple untrustworthy parties. Despite the bright side of smart contracts, several concerns continue to undermine their adoption, such as security threats, vulnerabilities, and legal issues. In this paper, we present a comprehensive survey of blockchain-enabled smart contracts from both technical and usage points of view. To do so, we present a taxonomy of existing blockchain-enabled smart contract solutions, categorize the included research papers, and discuss the existing smart contract-based studies. Based on the findings from the survey, we identify a set of challenges and open issues that need to be addressed in future studies. Finally, we identify future trends.