A Blockchain-Based Pattern for Confidential and Pseudo-Anonymous Contract Enforcement

Block chain technology provides a decentralized and secure platform for executing transactions. Smart contracts in Ethereum have been proposed as the mechanism to automate legal contracts securely without the involvement of third parties. Yet, there are still several issues to be resolved especially regarding the updating of smart contracts in blockchain as well as the use of blockchain as part of a legal smart contracts system. In this work we propose a methodology and an architecture for building and deploying legal contracts in the blockchain. As the blockchain is immutable, we cannot update the code of the smart legal contracts, but in real life applications updating of contracts is a requirement that cannot be ignored. In this paper we address the problem of contract update by introducing a new versioning system that keeps track of the changes and links the different versions using a linked list. Moreover, we propose a system architecture where the user interface, the application logic and the blockchain are smoothly integrated in a manner that each part of the system contributes for producing a flexible and transparent execution. We show the applicability of our approach by implementing a system for the case of a rental agreement.

Smart contracts in blockchain systems are widely used as automated agreements that can expedite the execution of a contract. Based on the characteristics of smart contracts analyzed through agreements in the Indonesian Civil Code (BW), it can be concluded that smart contracts can be legally used in contractual legal activities in Indonesia. This is because smart contracts meet the requirements outlined in the BW as guidelines for contract formation, particularly concerning the validity of contracts. Using a normative method, which employs literature as legal material for this writing, the result shows that the validity of smart contracts in blockchain, based on Indonesian contract law, aligns with the contract law that fulfills the requirements of Article 1320 BW. Smart contracts can also be classified as standard agreements where the parties agree based on an existing and mutually agreed-upon contract. Until now, there are no specific regulations regarding smart contracts in Indonesia, even though smart contracts are already widely used in the country.

Bridging the gap: Predictive contracts in blockchain-achieving recalibration for industrial networks

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.

There are spells in the world: incantations that can transform reality through the power of procedural utterances. The marriage vow, the courtroom sentence, the shaman’s curse: these words are codes that change reality. (Finn 90) Introduction As a child, stories on magic were “opportunities to escape from reality” (Brugué and Llompart 1), or what Rosengren and Hickling describe as being part of a set of “causal belief systems” (77). As an adult, magic is typically seen as being “pure fantasy” (Rosengren and Hickling 75), while Bever argues that magic is something lost to time and materialism, and alternatively a skill that Yeats believed that anyone could develop with practice. The etymology of the word magic originates from magein, a Greek word used to describe “the science and religion of the priests of Zoroaster”, or, according to philologist Skeat, from Greek megas (great), thus signifying "the great science” (Melton 956). Not to be confused with sleight of hand or illusion, magic is traditionally associated with learned people, held in high esteem, who use supernatural or unseen forces to cause change in people and affect events. To use magic these people perform rituals and ceremonies associated with religion and spirituality and include people who may identify as Priests, Witches, Magicians, Wiccans, and Druids (Otto and Stausberg). Magic as Technology and Technology as Magic Although written accounts of the rituals and ceremonies performed by the Druids are rare, because they followed an oral tradition and didn’t record knowledge in a written form (Aldhouse-Green 19), they are believed to have considered magic as a practical technology to be used for such purposes as repelling enemies and divining lost items. They curse and blight humans and districts, raise storms and fogs, cause glamour and delusion, confer invisibility, inflict thirst and confusion on enemy warriors, transform people into animal shape or into stone, subdue and bind them with incantations, and raise magical barriers to halt attackers. (Hutton 33) Similarly, a common theme in The History of Magic by Chris Gosden is that magic is akin to science or mathematics—something to be utilised as a tool when there is a need, as well as being used to perform important rituals and ceremonies. In TechGnosis: Myth, Magic & Mysticism in the Age of Information, Davis discusses ideas on Technomysticism, and Thacker says that “the history of technology—from hieroglyphics to computer code—is itself inseparable from the often ambiguous exchanges with something nonhuman, something otherworldly, something divine. Technology, it seems, is religion by other means, then as now” (159). Written language, communication, speech, and instruction has always been used to transform the ordinary in people’s lives. In TechGnosis, Davis (32) cites Couliano (104): historians have been wrong in concluding that magic disappeared with the advent of 'quantitative science.’ The latter has simply substituted itself for a part of magic while extending its dreams and its goals by means of technology. Electricity, rapid transport, radio and television, the airplane, and the computer have merely carried into effect the promises first formulated by magic, resulting from the supernatural processes of the magician: to produce light, to move instantaneously from one point in space to another, to communicate with faraway regions of space, to fly through the air, and to have an infallible memory at one’s disposal. Non-Fungible Tokens (NFTs) In early 2021, at the height of the pandemic meta-crisis, blockchain and NFTs became well known (Umar et al. 1) and Crypto Art became the hot new money-making scheme for a small percentage of ‘artists’ and tech-bros alike. The popularity of Crypto Art continued until initial interest waned and Ether (ETH) started disappearing in the manner of a classic disappearing coin magic trick. In short, ETH is a type of cryptocurrency similar to Bitcoin. NFT is an acronym for Non-Fungible Token. An NFT is “a cryptographic digital asset that can be uniquely identified within its smart contract” (Myers, Proof of Work 316). The word Non-Fungible indicates that this token is unique and therefore cannot be substituted for a similar token. An example of something being fungible is being able to swap coins of the same denomination. The coins are different tokens but can be easily swapped and are worth the same as each other. Hackl, Lueth, and Bartolo define an NFT as “a digital asset that is unique and singular, backed by blockchain technology to ensure authenticity and ownership. An NFT can be bought, sold, traded, or collected” (7). Blockchain For the newcomer, blockchain can seem impenetrable and based on a type of esoterica or secret knowledge known only to an initiate of a certain type of programming (Cassino 22). The origins of blockchain can be found in the research article “How to Time-Stamp a Digital Document”, published by the Journal of Cryptology in 1991 by Haber, a cryptographer, and Stornetta, a physicist. They were attempting to answer “epistemological problems of how we trust what we believe to be true in a digital age” (Franceschet 310). Subsequently, in 2008, Satoshi Nakamoto wrote The White Paper, a document that describes the radical idea of Bitcoin or “Magic Internet Money” (Droitcour). As defined by Myers (Proof of Work 314), a blockchain is “a series of blocks of validated transactions, each linked to its predecessor by its cryptographic hash”. They go on to say that “Bitcoin’s innovation was not to produce a blockchain, which is essentially just a Merkle list, it was to produce a blockchain in a securely decentralised way”. In other words, blockchain is essentially a permanent record and secure database of information. The secure and permanent nature of blockchain is comparable to a chapter of the Akashic records: a metaphysical idea described as an infinite database where information on everything that has ever happened is stored. It is a mental plane where information is recorded and immutable for all time (Nash). The information stored in this infinite database is available to people who are familiar with the correct rituals and spells to access this knowledge. Blockchain Smart Contracts Blockchain smart contracts are written by a developer and stored on the blockchain. They contain the metadata required to set out the terms of the contract. IBM describes a smart contract as “programs stored on a blockchain that run when predetermined conditions are met”. There are several advantages of using a smart contract. Blockchain is a permanent and transparent record, archived using decentralised peer-to-peer Distributed Ledger Technology (DLT). This technology safeguards the security of a decentralised digital database because it eliminates the intermediary and reduces the chance of fraud, gives hackers fewer opportunities to access the information, and increases the stability of the system (Srivastava). They go on to say that “it is an emerging and revolutionary technology that is attracting a lot of public attention due to its capability to reduce risks and fraud in a scalable manner”. Despite being a dry subject, blockchain is frequently associated with magic. One example is Faustino, Maria, and Marques describing a “quasi-religious romanticism of the crypto-community towards blockchain technologies” (67), with Satoshi represented as King Arthur. The set of instructions that make up the blockchain smart contracts and NFTs tell the program, database, or computer what needs to happen. These instructions are similar to a recipe or spell. This “sourcery” is what Chun (19) describes when talking about the technological magic that mere mortals are unable to comprehend. “We believe in the power of code as a set of magical symbols linking the invisible and visible, echoing our long cultural tradition of logos, or language as an underlying system of order and reason, and its power as a kind of sourcery” (Finn 714). NFTs as a Conceptual Medium In a “massively distributed electronic ritual” (Myers, Proof of Work 100), NFTs became better-known with the sale of Beeple’s Everydays: The First 5000 Days by Christie’s for US$69,346,250. Because of the “thousandfold return” (Wang et al. 1) on the rapidly expanding market in October 2021, most people at that time viewed NFTs and cryptocurrencies as the latest cash cow; some artists saw them as a method to become financially independent, cut out the gallery intermediary, and be compensated on resales (Belk 5). In addition to the financial considerations, a small number of artists saw the conceptual potential of NFTs. Rhea Myers, a conceptual artist, has been using the blockchain as a conceptual medium for over 10 years. Myers describes themselves as “an artist, hacker and writer” (Myers, Bio). A recent work by Myers, titled Is Art (Token), made in 2023 as an Ethereum ERC-721 Token (NFT), is made using a digital image with text that says “this token is art”. The word ‘is’ is emphasised in a maroon colour that differentiates it from the rest in dark grey. The following is the didactic for the artwork. Own the creative power of a crypto artist. Is Art (Token) takes the artist’s power of nomination, of naming something as art, and delegates it to the artwork’s owner. Their assertion of its art or non-art status is secured and guaranteed by the power of the blockchain. Based on a common and understandable misunderstanding of how Is Art (2014) works, this is the first in a series of editions that inscribe ongoing and contemporary concerns onto this exemplar of a past or perhaps not yet realized blockchain artworld. (Myers, is art editions). This is a simple example of their work. A lot of Myers’s work appears to be uncomplicated but hides subtle levels of sophistication that use all the tools available to conceptual artists by questioning the notion of what art is—a hallmark of conceptual art (Goldie

Nowadays, blockchain technology and industry has developed rapidly all over the world, which is inseparable from continuous innovation and improvement on smart contract technology. Therefore, by summarizing the working principle and application research status of blockchain smart contract, this paper analyzes the development and challenges of smart contract. Firstly, we introduce the model and operation principle of blockchain smart contract for the overall architecture, analyze the deployment process of smart contract with Ethereum, Hyperledger Fabric and EOSIO, and make a comparative analysis from the technical level. And taking Byteball, InterValue and IOTA platforms as examples, we introduce the deployment process and application potential for DAG-based blockchain smart contract. Additionally, we also summarize the application research of smart contract for international and Blockchain Oracle, and discuss its innovative application and development trend in the future. Secondly, we introduce the application status of smart contract with Ethereum and Hyperledger Fabric platforms from the aspects of financial transactions, Internet of things, medical applications, and supply chain, and further discuss EOS (enterprise operation system), Blockchain Oracle and other application fields. Furthermore, we introduce the application advantages and challenges to smart contract for industrial Internet from the fields of manufacturing, food industry, industrial Internet of things and industry 4.0. Finally, we discuss the challenges faced by smart contract with technical issues, analyzes the impact on large-scale applications and mining system on the sustainable development of smart contract, and looks forward to the future research direction of blockchain smart contract.

Blockchain smart contracts (SCs) have emerged as a transformative technology, enabling the automation and execution of contractual agreements without the need for intermediaries. However, as SCs evolve to become more complex in their decentralised decision-making abilities, there are notable difficulties in comprehending the underlying reasoning process and ensuring users’ understanding. The existing literature primarily focuses on the technical aspects of SC, overlooking the exploration of the decision-making process within these systems and the involvement of humans. In this paper, we propose a framework that integrates human-centered design principles by applying Situation Awareness (SA) and goal directed task analysis (GDTA) concepts to determine information requirements necessary to design eXplainable smart contracts (XSC). The framework provides a structured approach for requirements engineers to identify information that can keep users well-informed throughout the decision-making process. The framework considers factors such as the business logic model, data model, and roles and responsibilities model to define specific information requirements that shape SC behaviour and necessitate explanations. To guide the determination of information requirements, the framework categorises SC decision mechanisms into autonomy, governance, processing, and behaviour. The ExplanaSC framework promotes the generation of XSC explanations through three levels aligned with SA: XSC explanation for perception, XSC explanation for comprehension, and XSC explanation for projection. Overall, this framework contributes to the development of XSC systems and lays the foundation for more transparent, and trustworthy decentralized applications. The XSC explanations aims to facilitate user awareness of complex decision-making processes. The evaluation of the framework uses a case to exemplify the working of our framework, its added value and limitations, and consults experts in the field for feedback and refinements.

Blockchains-based smart contracts are disrupting the smart real estate sector of the smart cities. The current study explores the literature focused on blockchain smart contracts in smart real estate and proposes a conceptual framework for its adoption in smart cities. Based on a systematic review method, the literature published between 2000 and 2020 is explored and analyzed. From the literature, ten key aspects of the blockchain smart contracts are highlighted that are grouped into six layers for adopting the smart contracts in smart real estate. The decentralized application and its interactions with Ethereum Virtual Machine (EVM) are presented to show the development of a smart contract that can be used for blockchain smart contracts in real estate. Further, a detailed design and interaction mechanism are highlighted for the real estate owners and users as parties to a smart contract. A list of functions for initiating, creating, modifying, or terminating a smart contract is presented along with a stepwise procedure for establishing and terminating smart contracts. The current study can help the users enjoy a more immersive, user-friendly, and visualized contracting process, whereas the owners, property technologies (Proptech) companies, and real estate agents can enjoy more business and sales. This can help disrupt traditional real estate and transform it into smart real estate in line with industry 4.0 requirements.

Blockchain smart contracts can support the decentralisation of business processes, but due to smart contracts’ specifics, their development is a complicated process. Introducing model-driven development principles in smart contract development can facilitate requirement specification, design, and implementation activities. This paper presents a model-driven development method MDAsmartCD (Model-Driven Architecture-based Smart Contract Development) to alleviate smart contract development by supporting the complete MDA life cycle, covering the definition of Computation-Independent Model, Platform-Independent Model, and two instances of Platform-Specific Models. In MDAsmartCD, model transformations (model-to-model and model-to-text) are used to produce smart contract code in the Hyperledger Fabric platform Go and the Ethereum platform Solidity programming languages. The method application was demonstrated by implementing the smart contract for the hackathon solution and executing the generated Solidity and Go smart contracts in the workflow of issuing certificates for hackathon participants. During the execution of the workflow, both deployed smart contracts behaved identically and recorded analogous results in respective blockchain data storages. This demonstrated that the MDAsmartCD method enables the generation of compilable and executable smart contract code, ready for deployment on a blockchain platform.

Since Friedrich Kessler wrote “Contracts of Adhesion-Some Thoughts About Freedom of Contract” in 1943, condemning narrow adherence to the principle of “freedom to contract” in the face of large scale enterprises’ growing preference for standard form contracts, Courts have balanced their desire to uphold contracts while protecting weaker parties from adhesion. Today, they face similar challenges with the rise of code-driven smart contracts and blockchain governance. Similar to Kessler’s world, where standard-form contracts were a tool for “excluding or controlling the ‘irrational factor’ in litigation” such as uncertain outcomes of judicial interpretation, automated smart contracts aim to put themselves outside the control of both contractual parties and the courts, thus removing any ability to breach or tamper with the original terms. Smart contract advocates contend that removing the judiciary as the governing body over contract law and imposing contractual performance via decentralized blockchain governance improves efficiency and certainty.
 But, how much can one really write a contract that completely circumvents the potential for legal intervention or judicial enforcement? Will smart contracts finally achieve the complete separation between private and public law that advocates of “freedom to contract” originally claimed, or does the common law legal system’s deep-rooted belief in the rule of law and due process prevent the judiciary from being excluded from contract enforcement regardless the medium? And is there a risk that, as smart contract sceptics posit, smart contract platforms and blockchain governance create a new feudal order with a “potentially illegitimate exercise of power” and “normatively suspect” wealth distributions?
 The short answer, as this paper will demonstrate, is that as long as smart contracts meet the traditional requirements of a contract, they cannot fall outside the establish legal system’s purview. The only thing a smart contract truly adds to traditional contracts is automated execution that is enforced by the blockchain’s consensus mechanism; this may provide some efficiency to the legal system by streamlining basic performance but it cannot be the only form of governance over smart contracts. While there may be procedural challenges to undoing or enforcing specific performance under smart contracts because of their decentralized features, any substantive problems that could occur within a smart contract are imminently addressable with and must be subjected to the principles and remedies found in traditional contract law. Finally, I will conclude with current developments in smart contracts which point to a potential for them to become an integral part of our legal system going forward. Overall, I will argue that smart contracts, if carefully drafted to consider potential pitfalls and the future needs of contracting parties to amend or enforce, can hold the potential to provide efficiencies and greater legal certainty to contracting parties. This is achieved, not through circumventing the legal system, but by working with it to automate simple performance enforcement and deferring more complex contractual breakdowns to the judiciary.

One of the building blocks of our legal and economic systems in society is the indispensable reliance on contracts and trust systems to protect individual rights. Recently smart contracts are becoming prominent parts of various blockchain platforms. The goal of smart contracts is to eliminate the third party and centralized trust systems. Due to recent emergence of smart contracts, there is no well-defined framework that researchers can use to evaluate smart contracts under various blockchain platforms and differentiate between them. In this work, a survey on the prominent smart contract landscape specially those based on blockchain have been conducted. Based on the survey, an evaluation framework to assess smart contracts has been proposed. The framework is a set of criteria based on two major aspects; infrastructure related and development related criteria. The evaluation framework was peer-reviewed for reliability and validity. To measure the applicability of the proposed framework, it has been used to empirically evaluate some of the most prominent smart contract platforms. The results of the empirical evaluation have shown that the Ethereum blockchain smart contract exceeds the others in terms of development tools, resources, and community support. EOS blockchain smart contracts have the best execution speeds, and transaction costs. Lastly, Stellar blockchain has predictability and the best transaction builder to use in smart contract development concerning user friendliness. Recommendations for smart contract developers are provided in light of the research.

A smart contract is an agreement between two or more parties, which is executed by the computer code. The code does the execution without giving either party the ability to back out, so it ensures the trustless execution. The smart contract is one of the most important features in blockchain applications, which implements trusted transactions without third parties. However, with the rapid development, blockchain smart contracts have also exposed many security problems, and some attacks caused by contract vulnerabilities have led to terrible losses. In order to better deal with such dilemma, making a comprehensive survey about the security verification of blockchain smart contracts from major scientific databases is quite indispensable. Even though the significance of studying security verification of blockchain smart contracts is evident, it is really fresh yet. The major contributions of our survey work come from three aspects. First, after retrieving all-sided research studies, we select 53 most related papers to show the state-of-the art of this topic, where 20 papers focus on dealing with security assurance of blockchain smart contracts, and 33 papers focus on the correctness verification of blockchain smart contracts. Second, we propose a taxonomy toward the topic of security verification of blockchain smart contracts and discuss the pros and cons of each category of related studies. Third, through in-depth analysis of these studies, we come to know that the correctness verification of smart contracts based on the formal method has already become the more significant and more effective method to validate whether a smart contract is credible and accurate. So, we further present representative studies of formal verification of smart contracts in detail to demonstrate that using a formal method to validate blockchain smart contracts must have a promising and meritorious future.

Blockchain is a revolutionary technology that offers a new kind of inventive service. It can handle a variety of sophisticated issues associated with the secrecy, integrity, and availability of fast and secure distributed systems. This concept paper begins by addressing the shift in people's attitudes towards the insurance industry, particularly in Malaysia, and then goes on to understand how the Unified Theory of Acceptance and Use of Technology (UTAUT), Task Technology Fit (TTF), and Initial Trust Model (ITM), influence behavioural intentions in using blockchain smart contracts. A digital insurance platform must be redefined after the increase in online insurance sales transactions prompted by COVID-19 to satisfy the market's expectations. Whereas traditional paper contracts rely on middlemen for execution, blockchain smart contracts are now based on blockchains, which include an immutable record of data and the ability to remove single points of failure. Despite the growing popularity of blockchain research in recent years, research on blockchain smart contract adoption behaviour at the individual level concerning insurance services remains limited. Hence, this study utilises the three models to characterise how performance expectancy, technological context, and initial trust interact to forecast behavioural intention. Furthermore, we stressed the need for additional research to demonstrate the intention to employ blockchain smart contracts is impacted by performance anticipation, technical environment, and personal initial trust. Based on the review, we will design realistic research that will incorporate prospects for theoretical progress as well as empirical discoveries in blockchain smart contract studies. The findings are intended to assist policymakers in developing suitable and improved strategies for capturing interest in blockchain smart contract insurance services in the Malaysian market. We also believe that the evolution of blockchain technology in tandem with smart contracts will enable the creation of new sorts of innovative services, such as insurance.

Physical documents have many challenges, due to being difficult to exchange and the potential of being lost and sabotaged. Digital documents seem to address some of these challenges, but because of the use of the Internet and reliance on third parties to share and preserve such documents, the privacy and integrity of the digital documents became difficult to maintain. The blockchain technology that Satoshi Nakamoto has proposed for financial transactions can be used to solve the problems of trust in centralized systems and the subversion and alteration thatthese transactions may be exposed to. Blockchain-based systems have shown their effectiveness and ability to solve most security problems related to exchanging systems' transactions. Hence,A decentralized system for exchanging digital documents, using Ethereum blockchain and InterPlanetary File System (IPFS), has been proposed to overcome the problems of using trusted third-parties in exchanging digital documents. The proposed system provides immutable and irreversible logs of the process of sending and receiving documents. In this framework, all registered users can encrypt the documents using the Advanced Encryption Standard (AES) Algorithm, send, and receive documents using the Ethereum Blockchain's smart contract. The framework was simulated locally using Ganache Blockchain and tested on the official Ethereum test network Ropsten, and the experimental results showed the feasibility of the proposed scheme. The smart contract used in the Ethereum blockchain was written in the Solidity programming language, and the website that was needed to interact with the blockchain was built using React and other different javascript libraries like web3. Additionally, Metamask wallet was used to create the Ethereum accounts which are required to connect and communicate with the Smart Contract that is implemented in the Ethereum blockchain. Finally, the model's results indicated that the model may cost an average of 0.0552$ per transaction, and this shows that the system is affordable. Also, the model has satisfied the three main security requirements which are confidentiality, integrity, and availability by using the suitable countermeasure for each one of them.

The emerging blockchain technology supports decentralized computing paradigm shift and is a rapidly approaching phenomenon. While blockchain is thought primarily as the basis of Bitcoin, its application has grown far beyond cryptocurrencies due to the introduction of smart contracts. Smart contracts are self-enforcing pieces of software, which reside and run over a hosting blockchain. Using blockchain-based smart contracts for secure and transparent management to govern interactions (authentication, connection, and transaction) in Internet-enabled environments, mostly IoT, is a niche area of research and practice. However, writing trustworthy and safe smart contracts can be tremendously challenging because of the complicated semantics of underlying domain-specific languages and its testability. There have been high-profile incidents that indicate blockchain smart contracts could contain various code-security vulnerabilities, instigating financial harms. When it involves security of smart contracts, developers embracing the ability to write the contracts should be capable of testing their code, for diagnosing security vulnerabilities, before deploying them to the immutable environments on blockchains. However, there are only a handful of security testing tools for smart contracts. This implies that the existing research on automatic smart contracts security testing is not adequate and remains in a very stage of infancy. With a specific goal to more readily realize the application of blockchain smart contracts in security and privacy, we should first understand their vulnerabilities before widespread implementation. Accordingly, the goal of this paper is to carry out a far-reaching experimental assessment of current static smart contracts security testing tools, for the most widely used blockchain, the Ethereum and its domain-specific programming language, Solidity to provide the first...