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Smart Contracts LifeCycle 1) Creation of smart contracts: Several involved parties first negotiate on the obligations, rights and prohibitions on contracts. After multiple rounds of discussions and negotiations, an agreement can reach. Lawyers or counselors will help parties to draft an initial contractual agreement. Software engineers then convert this agreement written in natural languages into a smart contract written in computer languages including declarative languages and logic-based rule languages (D. Harz, 2018). Similar to the development of computer software, the procedure of the smart contract conversion is composed of design, implementation and validation (i.e., testing). It is worth mentioning that the creation of smart contracts is an iterative process involving with multiple rounds of negotiations and iterations. Meanwhile, it is also involved with multiple parties, such as stakeholders, lawyers and software engineers.
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Smart contracts are computer programs that can be consistently executed by a network of mutually distrusting nodes, without the arbitration of a trusted authority. Being embedded in blockchains, smart contracts enable the contractual terms of an agreement to be enforced automatically without the intervention of a trusted third party. Over the last...
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... is worth mentioning that during deployment, execution and completion of a smart contract, a sequence of transactions has been executed (each corresponding to a statement in the smart contract) and stored in the blockchain. Therefore, all these three phases need to write data to the blockchain as shown in Figure 2. ...
Citations
... The blockchain is a continuously updated, chronologically organized, and publicly accessible ledger containing data about ownership and transactions (Sahai and Pandey 2020). The use of cryptographic principles guarantees the enduring immutability of records and establishes smart contracts as a highly secure automation technology (Shailak Jani 2020). Within the realm of smart contracts, the blockchain enables agreements to be transparent to the involved contracting parties and to be automatically activated when predefined conditions arise (Mohanta et al. 2018). ...
... Having smart contracts written on Ethereum ensures the retroactive immutability of transactions (Kim and Shin 2019). Whenever the agreed terms and/or situation(s) occur, the smart contract completes the related and predefined action(s) (Shailak Jani 2020). An exact (pre) specified execution is guaranteed which provides security to involved parties. ...
... This second step (2) involves placing the smart contract onto a blockchain, rendering it transparent to all parties involved (figure 1). As it is customary in blockchain technology, each transaction and completion of the smart contract are recorded in the genesis block, allowing for easy tracing at any given time (Shailak Jani 2020). This technology provides the transparency and security discussed earlier. ...
Crowdworking is increasingly being applied by companies to outsource tasks beyond their core competencies flexibly and cost-effectively to an unknown group. However, the anonymous and financially incentivized nature of crowdworkers creates information asymmetries and conflicts of interest, leading to inefficiencies and intensifying the principal-agent problem. Our paper offers a solution to the widespread problem of inefficient Crowdworking campaigns. We first derive the currently applied Crowdworking campaign process based on a qualitative study. Subsequently, we identify the broadest adverse selection and moral hazard problems in the process. We then analyze how the blockchain application of smart contracts can counteract those challenges and develop a process model that maps a Crowdworking campaign using smart contracts. We explain how our developed process significantly reduces adverse selection and moral hazard at each stage. Thus, our research provides approaches to make online labor more attractive and transparent for companies and online workers.
... A smart contract is an agreement whose execution is automated or semi-automated. A common way of execution is by a network of mutually distrusting nodes, in which no trusted authority is required [ 3]. Blockchain technology enables smart contract fulfillment and can reduce costs, effort, delays, and other administration-related potential errors [ 11]. ...
A smart contract is an agreement whose execution is automated or semi-automated. DasContract was introduced in 2019–2021 as a domain-specific language for smart-contract modeling, with the ability to generate code in a programming language. DasContract’s former modeling environment had various limitations, both technical and design related. Some of these limitations have previously been recognized in the literature in several dimensions. In this study, we propose further guidelines for contract modeling to address error prevention in the modeling environment, thus contributing to improved smart-contract specifications.KeywordsSmart contractsDomain-specific languageBPMNBlockchain
... Smart contract memungkinan adanya pengembangan yang lebih pada teknologi blockchain karena keduanya dibangun menggunakan ekosistem yang sama, yaitu dengan jaringan terdesentralisasi. Blockchain yang pada awalnya hanya digunakan untuk melakukan proses komputasi sederhana, seperti pencatatan data transaksi, tetapi sekarang telah dikembangkan untuk melakukan proses komputasi yang lebih kompleks dengan integrasi smart contract [15]. Kombinasi dari teknologi blockchain dan smart contract ini dinamakan Decentralized Application (DApp). ...
Blockchain merupakan teknologi buku besar yang bersifat decentralized. Blockchain memiliki protokol consensus sebagai kesepakatan bersama dalam pengelolaan basis data. Contoh penerapan blockchain yaitu ethereum. Kelebihan ethereum yaitu dapat menjalankan program atau aturan yang disebut sebagai smart contract. Proses perubahan data pada ethereum memerlukan biaya transaksi atau gas fee. Nilai gas fee ini fluktuatif menyesuaikan gas fee terendah saat ini, kepadatan jaringan dan kompleksitas transaksi. Smart contract ethereum tidak efisien untuk menyimpan data yang berukuran besar karena semakin besar data yang disimpan maka semakin kompleks transaksi yang perlu dilakukan. Untuk meningkatkan efisiensi gas fee smart contract maka dilakukan sebuah penelitian dengan menerapkan InterPlanetary File System (IPFS). Teknik yang digunakan yaitu mengkombinasikan teknologi IPFS dengan smart contract ethereum untuk mengurangi kompleksitas transaksi ketika proses penyimpanan data penggalangan dana ke smart contract ethereum. Penerapan IPFS pada aplikasi penggalangan dana membutuhkan gas fee 0,00311847-0,003379868 ETH dengan kecepatan transaksi 12-36 detik. Berdasarkan pengujian sebanyak 40 kali dengan data yang berbeda, penerapan IPFS dapat menurunkan gas fee dengan rata-rata hingga 94,39% dan kecepatan transaksi sistem yang menerapkan IPFS lebih besar 13,55% dari sistem yang tidak menerapkan IPFS.
... After Satoshi Nakamoto used blockchain technology to create Bitcoin in 2009 [10], many new blockchain ecosystems and related cryptocurrencies have been introduced. According to market capitalization, Ethereum [11] is the second most popular blockchain after Bitcoin, and it is currently the largest blockchain-based platform that provides a Turing-complete language to support smart contracts [12]. A smart contract is a digital contract residing in the blockchain and can self-execute when the preset conditions are met. ...
... With the development of smart contracts, more and more smart contracts are deployed on different blockchain platforms, such as Ethereum, Fabric, ESO, etc. [10]. Among the many blockchain systems that support the operation of smart contracts, Ethereum, as the earliest blockchain platform recognized to support the operation of smart contracts, has now become the largest blockchain platform in the world. ...
Smart contracts are decentralized applications running on blockchain platforms and have been widely used in a variety of scenarios in recent years. However, frequent smart contract security incidents have focused more and more attention on their security and reliability, and smart contract vulnerability detection has become an urgent problem in blockchain security. Most of the existing methods rely on fixed rules defined by experts, which have the disadvantages of single detection type, poor scalability, and high false alarm rate. To solve the above problems, this paper proposes a method that combines Bi-LSTM and an attention mechanism for multiple vulnerability detection of smart contract opcodes. First, we preprocessed the data to convert the opcodes into a feature matrix suitable as the input of the neural network and then used the Bi-LSTM model based on the attention mechanism to classify smart contracts with multiple labels. The experimental results show that the model can detect multiple vulnerabilities at the same time, and all evaluation indicators exceeded 85%, which proves the effectiveness of the method proposed in this paper for multiple vulnerability detection tasks in smart contracts.
... A smart contract is a computer protocol running on the blockchain, which is written by the Turing-complete language, typically Solidity. So far, tens of thousands of smart contracts have been deployed on various blockchain platforms, e.g., Ethereum [20], EOS [22], VNT Chain [23], and the number is still growing rapidly. ...
Smart contract, one of the most successful applications of blockchain, is taking the world by storm, playing an essential role in the blockchain ecosystem. However, frequent smart contract security incidents not only result in tremendous economic losses but also destroy the blockchain-based credit system. The security and reliability of smart contracts thus gain extensive attention from researchers worldwide. In this survey, we first summarize the common types and typical cases of smart contract vulnerabilities from three levels, i.e., Solidity code layer, EVM execution layer, and Block dependency layer. Further, we review the research progress of smart contract vulnerability detection and classify existing counterparts into five categories, i.e., formal verification, symbolic execution, fuzzing detection, intermediate representation, and deep learning. Empirically, we take 300 real-world smart contracts deployed on Ethereum as the test samples and compare the representative methods in terms of accuracy, F1-Score, and average detection time. Finally, we discuss the challenges in the field of smart contract vulnerability detection and combine with the deep learning technology to look forward to future research directions.
... Smart contracts are small applications that are saved on a blockchain and operated in parallel by many validators. The term "smart contract" was coined by Szabo (1994) [20]. Many agreements might be "hidden in the hardware and software with which we engage so that a breach of contract is costly... for the offender," according to Szabo, who created the concept using the example of a vending machine. ...
Blockchain has become an unavoidable future in enterprise finance, particularly enabling and securing cross-company transactions. By introducing a comparable notion of smart contract, the trusted sub-ledger operation (TSLO), this article will propose a complete architecture based on the Blockchain to solve the traceability and validity of accounting data by assets groupement. TSLO is a more flexible and adaptable method for asset management in the corporate accounting system and the enterprise resource planner. This method is built on a decentralized microservices tree (DMST) and is an extendable E-Binding form of TEA (Triple Entry Accounting). Instead of using a multi-ledger architecture, the Hyperledger Fabric skeleton, limited to participant channels inside one entity or organization, our approach uses decentralized sub-ledgers with an implementation tree (DMST) for an assets-driven transaction. Furthermore, the government’s audit and taxation procedures for financial groups are more accessible by combining Proof of Authority and Proof of Stake to assure the logic of More stake more reputation to preserve.
... Smart contracts consist of transactions that are stored and replicated in the blockchain's ledger. Smart contracts extend blockchains' utility from simply keeping a record of financial transactions to automatically executing multi-participants agreement conditions [9]. Those agreements could be identification mechanisms of IoT entities, IoT devices services payments, peer-to-peer IoT messaging scheduling, or any other IoT system operations. ...
... After that, the smart contract code is submitted to the blockchain during the publication phase where participating nodes receive it as part of a transaction block. Once the block gets confirmed by the majority of nodes, the contract becomes ready for execution and thus is deployed to platforms on top of a blockchain where all parties can access it through this blockchain [9], [28]. ...
... Consequently, the digital assets of the involved parties get unlocked. Hereby, the smart contract has completed the whole life cycle [9]. ...
The remarkable increase in the number of interconnected smart devices in today’s Internet of things networks introduces more challenges related to security, trust, and centralization, which require more effective solutions. Fortunately, blockchain technology has recently emerged as a potential rescuer for IoT-based solutions due to its decentralization and enhanced security features. It is usual for smart contracts to arise in handling and processing the generated data when IoT devices are combined with blockchain. However, blockchain and smart contracts need to interact with input data of the same level of trust to guarantee correct applications execution. This implies using oracles to provide trust compatibility between inserted information collected from IoT devices and blockchain and smart contracts. Therefore, this study adopts a methodology that was shaped based on current literature and design and experiments to provide a full narrative of the process of combining two of the most intriguing systems in today’s world of technology, namely, blockchain and IoT including a very important part of the comprehensive system, viz. blockchain oracle. Moreover, it was found that the literature lacks a complete view of the IoT-blockchain integration process that covers all its important and related aspects. Therefore, this work is an attempt to fill the gap in literature and contribute to the body of knowledge by surveying the literature about existing IoT-blockchain architectures and shed light on the role of blockchain in addressing IoT issues while demonstrating the concept of oracles as well as their functions in addition to the main operating blockchain oracles. Additionally, this work illustrates a CO
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measuring use case where a smart contract is developed and tested as part of two proposed oracle-based designs. The obtained results demonstrate a full picture of a practical integrated IoT-blockchain system architecture.
... Smart contracts are programs deployed and run on blockchain networks. These programs extend the functionality of a blockchain and allow untrusted parties to establish trust in the truthful execution of an agreement [3]. ...
... Smart contracts are supported on many blockchain platforms (e.g., Ethereum [14], Hyperledger [15], etc.), but may be very limited on others (e.g., Bitcoin [16]). They extend the functionality of a blockchain and allow untrusted parties to establish trust in the truthful execution of the agreement [3]. In short, smart contracts are programs deployed and run on blockchain networks, and are capable of executing triggers, rules, and business logic to enable transactions [17]. ...
One of the key benefits of blockchain technology is its ability to keep a permanent, unalterable record of transactions. In business environments, where companies interact with each other without a centralized authority to ensure trust between them, this has led to blockchain platforms and smart contracts being proposed as a means of implementing trustworthy collaborative processes. Software engineers must deal with them to ensure the quality of smart contracts in all phases of the smart contract lifecycle, from requirements specifications to design and deployment. This broad scope and criticality of smart contracts in business environments means that they have to be expressed in a language that is intuitive, easy-to-use, independent of the blockchain platform employed, and oriented towards software quality assurance. In this paper we present a key component: a first outline of a UML-based smart contract meta-model that would allow us to achieve these objectives. This meta-model will be enriched in future work to represent blockchain environments and automated testing.
... Smart contract: Smart contracts are public, self-executing code that runs when certain trigger conditions are met [15]- [17]. For example, it can be a function that sends a message to a specific account when the account balance reaches a predefined value. ...
A smart Ponzi scheme is a new form of economic crime that uses Ethereum smart contract account and cryptocurrency to implement Ponzi scheme. The smart Ponzi scheme has harmed the interests of many investors, but researches on smart Ponzi scheme detection is still very limited. The existing smart Ponzi scheme detection methods have the problems of requiring many human resources in feature engineering and poor model portability. To solve these problems, we propose a data-driven smart Ponzi scheme detection system in this paper. The system uses dynamic graph embedding technology to automatically learn the representation of an account based on multi-source and multi-modal data related to account transactions. Compared with traditional methods, the proposed system requires very limited human-computer interaction. To the best of our knowledge, this is the first work to implement smart Ponzi scheme detection through dynamic graph embedding. Experimental results show that this method is significantly better than the existing smart Ponzi scheme detection methods.
