Blockchain Business Model and Security

Smart contracts on a blockchain network can be implemented to control digital value. A key question that arises is the extent to which smart contracts can, or should, operate as “smart legal contracts”. Simply put, can smart contracts meet requirements of validity at law and practical efficacy. In order to achieve the goal of value maximization, the efforts of policy-makers, standards organisations and regulators should be informed by first principles. Standards, and other regulatory activities, must be driven by consideration of the techno-legal functions of contracting. Blockchain-based smart contracts offer the potential to reduce transaction costs through new methods of stateful computation. When applied to commercial transactions, smart contracts can represent enforcement of an executed state. This paper argues that distributed ledger and smart contracts standards should seek to provide sufficient flexibility to facilitate contracting parties to coordinate in an optimal manner.

With the growing utility of blockchain technology, the desire for reciprocal interactions among different blockchains is growing. However, most operational blockchain networks currently operate in a standalone setting. This fragmentation in the form of isolated blockchains creates interoperability difficulties, inhibiting the adoption of blockchains in various ecosystems. Interoperability is a key factor in the healthcare domain for sharing EHRs of patients registered in independent blockchain networks. Each blockchain network could have its own rules and regulations, obstructing the exchange of EHRs for improving diagnosis and treatments. Examples include patients being treated by healthcare providers in different countries or regions, or within one country but with a different set of rules per state or emirate. By contrast, a federation of blockchain networks can provide better communication and service to stakeholders in healthcare. Thus, solutions for facilitating inter-blockchain communication in such a blockchain federation are needed. However, this possibility has not been fully explored, and further investigations are still being conducted. Hence, the present study proposes a transaction-based smart contract triggering system for inter-blockchain communication, enabling EHR sharing among independent blockchains. We use local and global smart contracts that will be executed once a transaction is created in the blockchain. Local smart contracts are used for EHR sharing within the blockchain, whereas global smart contracts are used for EHR sharing among independent blockchains. The experimental setup is conducted using the Hyperledger Fabric blockchain platform. Inter-blockchain communication between two independent fabric networks is conducted through a global smart contract using Hyperledger Cactus for EHR sharing in a health federation setup. To the best of our knowledge, our study is the first to implement an inter-blockchain communication model in the healthcare domain.

In the last few years, the technological future becoming apparent by the introduction of smart contracts into mainstream technology, specifically in the development of Web3 and the metaverse. Smart contracts will play a vital role in the decentralization and autonomy of the day-to-day tasks that must be completed. Several literature reviews, considered secondary sources, highlight the current state of testing methods for smart contracts made for Blockchain applications. In this paper, we present the results from a systematic mapping study to give structure to the information found from primary sources. Systematic mapping is a well-known method to identify and categorize research papers in a field with an increasing amount of literature. For this systematic mapping, we searched for studies between 2017 and present-day (March 2022) and were able to find 303 results, from which 47 were selected, by specific inclusion and exclusion criteria, to be relevant to this study. A concept map was created from the information gathered from primary sources to the attributes such as research type, contribution type, blockchain network, smart contract language, development process, testing methods, and testing environment. We also categorized the trends and demographics found in the selected papers based on publication year, author’s country, and more. The results of this systematic mapping showed that this field is very new and quickly increasing with new research. The researchers that are interested in this field could use the results found to create opportunities for their future work.

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.

Blockchain technology, smart contract and microgrid systems have facilitated innovations and breakthroughs in the electricity industry. The once bundled electricity market dominated by a few key players is now gradually becoming unbundled to a more consumer-centric market due to these new technologies. To facilitate the use of community microgrids, this study develops a new trend in peer-to-peer energy trading. In this work, a model for a smart microgrid system, a decentralized energy trading platform based on blockchain, and smart contract technologies is proposed, considering an islanded community microgrid network of energy prosumers. Smart meters were used to ensure the bi-directional flow of data and power, thereby giving prosumers control over their power usage. Storage and validation of participants’ data are stored on the blockchain network, which has a strong feature of decentralization, transparency, security and data immutability. The smart contract automatically executes power delivery and transfer of tokens from the buyer’s wallet to the seller’s energy wallet based on the transaction logic and protocol. A web-user interface was designed to enable the ease of transactions by market participants and the web-user interface was designed on React.Javascript while the smart contract codes were done on the solidity programming language. Algorithms were also developed for the market trade operations in real time and sets of mathematical equations were formulated for energy pricing based on the supply and demand philosophies to curtail over-pricing and underpricing of energy.

Unmanned aerial vehicles (UAV), an emerging architecture that embodies flying ad-hoc networks, face critical privacy and security challenges, mainly when engaged in data-sensitive missions. Therefore, message authentication is a crucial security feature for drone communication. This paper presents a Blockchain-based Efficient, and Trusted Authentication scheme for UAV communication BETA-UAV, which exploits the inherent properties of blockchain technology concerning memorability and immutable to record communication sessions via transaction using a smart contract. The smart contract in BETA-UAV allows participants to publish and call transactions from the blockchain network. Furthermore, the transaction addresses are proof of freshness and trustworthiness for subsequent transmissions. Furthermore, we investigate the ability to resist active attacks, e.g., impersonation, replaying, and modification. In addition, we evaluate the gas costs associated with the smart contract's functions by implementing BETA-UAV on the Ethereum public blockchain. Comparing computation and communication over-heads shows that the proposed approach can save significant costs over traditional techniques.

Smart contracts are deployed and represented as bytecodes in blockchain networks, and these bytecodes are machine-readable codes. Only a small number of deployed smart contracts have their verified human-readable code publicly accessible to blockchain users. To improve the understandability of deployed smart contracts, we explored rule-based classification of smart contracts using iterative integration of fingerprints of relevant function interfaces and keywords. Our classification system included categories for standard contracts such as ERC20, ERC721, and ERC1155, and non-standard contracts like FinDApps, cross-chain, governance, and proxy. To do this, we first identified the core function fingerprints for all ERC token contracts. We then used an adapted header extractor tool to verify that these fingerprints occurred in all of the implemented functions within the bytecode. For the non-standard contracts, we took an iterative approach, identifying contract interfaces and relevant fingerprints for each specific category. To classify these contracts, we created a rule that required at least two occurrences of a relevant fingerprint keyword or interface. This rule was stricter for standard contracts: the 100% occurrence requirement ensures that we only identify compliant token contracts. For non-standard contracts, we required a minimum of two relevant fingerprint occurrences to prevent hash collisions and the unintentional use of keywords. After developing the classifier, we evaluated its performance on sample datasets. The classifier performed very well, achieving an F1 score of over 99% for standard contracts and a solid 93% for non-standard contracts. We also conducted a risk analysis to identify potential vulnerabilities that could reduce the classifier’s performance, including hash collisions, an incomplete rule set, manual verification bottlenecks, outdated data, and semantic misdirection or obfuscation of smart contract functions. To address these risks, we proposed several solutions: continuous monitoring, continuous data crawling, and extended rule refinement. The classifier’s modular design allows for these manual updates to be easily integrated. While semantic-based risks cannot be completely eliminated, symbolic execution can be used to verify the expected behavior of ERC token contract functions with a given set of inputs to identify malicious contracts. Lastly, we applied the classifier on contracts deployed Ethereum main network.

BackgroundAn estimated US $2.6 billion loss is attributed to health care fraud and abuse. With traditional health care claims verification and reimbursement, the health care provider submits a claim after rendering services to a patient, which is then verified and reimbursed by the payer. However, this process leaves out a critical stakeholder: the patient for whom the services are actually rendered. This lack of patient participation introduces a risk of fraud and abuse. Blockchain technology enables secure data management with transparency, which could mitigate this risk of health care fraud and abuse.ObjectiveThe aim of this study is to develop a framework using blockchain to record claims data and transactions in an immutable format and to enable the patient to act as a validating node to help detect and prevent health care fraud and abuse.MethodsWe developed a health care fraud and abuse blockchain technical framework and prototype using key blockchain tools and application layers including consensus algorithms, smart contracts, tokens, and governance based on digital identity on the Ethereum platform (Ethereum Foundation).ResultsOur technical framework maps to the claims adjudication process and focuses on Medicare claims, with the US Centers for Medicare and Medicaid Services (CMS) as the central authority. A prototype of the framework system was developed using the blockchain platform Ethereum (Ethereum Foundation), with its design features, workflow, smart contract functions, system architecture, and software implementation outlined. The software stack used to build the system consisted of a front-end user interface framework, a back-end processing server, and a blockchain network. React was used for the user interface framework, and NodeJS and an Express server were used for the back-end processing server; Solidity was the smart contract language used to interact with a local Ethereum blockchain network.ConclusionsThe proposed framework and the initial prototype have the potential to improve the health care claims process by using blockchain technology for secure data storage and consensus mechanisms, which make the claims adjudication process more patient-centric for the purposes of identifying and preventing health care fraud and abuse. Future work will focus on the use of synthetic or historic CMS claims data to assess the real-world viability of the framework.

Blockchain is a type of decentralized database where all data are kept in one large chain of interconnected blocks of data stored on a large number of servers around the world. Besides decentralization, an additional advantage of this technology is the absence of intermediaries in communication between participants in the process. With the advent of the Ethereum network which is based on blockchain technology, in addition to performing financial transactions, now it is possible to create programs that could be executed on this network. However, execution of these programs, known as Smart Contract, costs money that is billed on this network in the form of gas which is directly proportional to the complexity of the computer operations performed within these contracts. Optimizing the structure and content of smart contracts directly implies reducing the cost/gas for their execution. In this paper we propose the structure of smart contracts in the context of gas optimization for their execution.

Nakamoto’s Bitcoin is the first decentralized digital cash system that utilizes a blockchain to manage transactions in its peer-to-peer network. The newer generation of blockchain systems, including Ethereum, extend their capabilities to support deployment of smart contracts within their peer-to-peer networks. However, smart contracts cannot acquire data from sources outside the blockchain since the blockchain network is isolated from the outside world. To obtain data from external sources, smart contracts must rely on Oracles, which are agents that bring data from the outside world to a blockchain network. However, guaranteeing that the oracle’s off-chain nodes are trustworthy remains a challenge. A centralized oracle that relies on a single off-chain node creates a single point of failure. Therefore, a decentralized mechanism is necessary. One possible design for a decentralized oracle is to use a game mechanism that utilizes the Schelling-point theory to identify the correct data point among various data points reported by the oracle’s off-chain nodes. In this paper, we introduce Spartan Price Oracle (SPO), a decentralized oracle designed to provide accurate price data. SPO utilizes the Schelling-point theory in its game mechanism to ensure the accuracy of the price data it provides. The mechanism design of SPO is based on SchellingCoin but with two significant improvements. Firstly, SPO uses Kernel Density Estimation to estimate the probability density function of data points that are reported by multiple off-chain nodes. This enables SPO to identify the accurate data by determining the mode of the probability density function. Secondly, SPO utilizes a redistributive economic incentive model that incorporates an appeal mechanism to increases the maximum reward for its off-chain nodes. This model has

This concise review paper discusses the application of smart contracts to increase blockchain interoperability. The emergence of blockchain has opened many opportunities to explore the advantage of modern technology. Blockchain networks operate as isolated ecosystems, hindering the seamless transfer of assets and data across different platforms. This ecosystem leads to the inability to interact or communicate within the blockchain. Smart contracts present a promising solution for facilitating interoperability between blockchains. In this paper, the potential of smart contracts as bridge technologies between blockchains is explored. The design and implementation of smart contracts to enable secure, trust less communication and asset transfer between disparate blockchain networks are analysed. Several academic papers were reviewed to understand the existing research and development efforts towards smart contract-based interoperability solutions. The ongoing discourse on blockchain interoperability is contributed to by highlighting the potential of smart contracts as bridge technologies, identifying key challenges and research gaps in this domain, and providing insights for further development of secure and efficient cross-chain communication protocols.

Peer-to-peer (P2P) energy trading is emerging as a new mechanism for settling the exchange of energy between renewable energy generators and consumers. P2P provides a mechanism for local balancing when it is facilitated through distributed ledgers (‘blockchains’). Energy communities across Europe have uncovered the potential of this technology and are currently running pilots to test its applicability in P2P energy trading. The aim of this paper is to assess, using legal literature and legislation, whether the legal forms available to energy communities in the United Kingdom (UK) can help resolve some of the uncertainties around the individual use of blockchain for P2P energy trading. This includes the legal recognition of ‘prosumers’, the protection of their personal data, as well as the validity of ‘smart contracts’ programmed to trade energy on the blockchain network. The analysis has shown that legal entities, such as Limited Liability Partnerships and Co-operative Societies, can play a crucial role in providing the necessary framework to protect consumers engaging in these transactions. This is particularly the case for co-operatives, given that they can hold members liable for not respecting the rules set out in their (compulsory) governing document. These findings are relevant to other European countries, where the energy co-operative model is also used.

Academic certificates are essential to acknowledge one’s academic achievement. With the credentials, it can be used to develop a career in a desired industry based on the qualifications. However, nowadays, fake academic certificates are used by irresponsible individuals to apply for a job. Therefore, it is crucial for the employer to validate one’s academic certificate before offering them the job position. To validate, a certificate may be too troublesome and require a long time for the verification process. In addition, the employer must check with the certificate’s issuer, which can involve a lot of processes. Thus, to solve this problem, blockchain-based certificate verification is introduced where the issuer can store the certificates details inside a blockchain network with the help of a smart contract feature that is immutable and anti-counterfeit. Smart contract is written in Solidity programming language and executed in Remix IDE. In terms of security for this smart contract, only the certificate’s issuer is able to add, edit, modify, and delete the details stored. Not only that, the contract’s owner also unable to add data into the blockchain due to the decentralized feature of a blockchain network. The average execution time for the smart contract is 8.3 s. All changes made to the certificate’s details can be tracked; thus, changes to the previous recording are impossible. This system will benefit the university because the students' data can be stored in a system and can be retrieved anytime. For a third-party user such as the employer, it can save time to check the validity of the academic certificates they received because the system generates the confirmation of transaction in less than five seconds.KeywordsSmart contractBlockchainThird keyword

Disaster relief is a key aspect of humanism and humanitarian actions. The delivery of adequate supplies at the right time and right place is critical for survival and recovery of the affected people, animals, plants and other entities. Since every dollar counts towards saving a life, the traceability of the shipments must be ensured, and the organisations involved in the process need to be aware of the delivered items to avoid duplication of relief efforts. Responsive, efficient and transparent supply chains have been difficult to build and execute as many disasters occur in underdeveloped or developing countries with poor infrastructure, corruption and other challenges. This paper explores the application of blockchain technologies to create a database ledger that can assure traceability and reliability and also avoid duplication. The use of ‘smart contracts’, which can be automatically executed in a blockchain, to promote transparency in contracts and performance and the movement of money across all parties is also studied. Large organisations such as the United Nations (UN) or the World Health Organization (WHO), which often take the lead in organising the relief efforts, can initiate the development of blockchains for humanitarian logistics and draw manufacturers, transportation carriers, other logistics providers, banks and other partners into the blockchain network. Assuring both the aid donors and the recipients that the funds have been used wisely and transparently will expand future aid contributions and enable more effective relief to disaster areas. This is especially critical now as climate changes on our planet are expected to result in more disasters with extremely dire consequences, especially in poorer regions of the world.

Blockchain provides an immutable distributed ledger for storing transactions. One of the challenges of blockchain is the particular processing of dynamic queries due to accumulating costs. Complex Event Processing (CEP) provides efficient and effective support for this in a way, however, that is difficult to integrate with blockchain. This paper addresses the research challenges of integrating blockchain with CEP. More specifically, we envision an effective development environment in which (i) event-driven smart contracts are modeled in a graphical way, which are, in turn, (ii) automatically transformed into complementary code that is deployed in both a CEP engine and a blockchain network, and then (iii) executed on off-chain CEP applications which, connected to different data sources and sinks, automatically invoke smart contracts when event pattern conditions are met. We follow a classic systems engineering approach for defining the concepts of our system, called CEPchain, which addresses the described requirements. CEPchain was evaluated using a real-world case study for vaccine delivery, which requires an unbroken cold chain. The results demonstrate that our approach can be applied without requiring experts on event processing and smart contract languages. Our contribution simplifies the design of integrated CEP and blockchain functionality by hiding implementation details and supporting efficient deployment.