In the Blockchain context, Smart Contracts are computer programs that run on the Ethereum platform. Benefiting from the properties of Blockchain, SCs development represents a major challenge to developers, as the code is deployed to an immutable system, besides the Ethereum platform is still evolving. This paper highlights how we can exploit model-driven engineering for generating long terms and high productivity smart contracts. It reviews researches on Smart Contracts generation in the Ethereum blockchain from a model-driven perspective. Based on the studied approaches, we defined a comparative framework to outline the advantages and disadvantages of each approach. The result can be used as a basis of tool selection for specific development aspects of SCs.
Massimo Bartoletti, James Hsin-yu Chiang, Alberto Lluch Lafuente
Automated market makers (AMMs) are one of the most prominent decentralized finance (DeFi) applications. AMMs allow users to trade different types of crypto-tokens, without the need to find a counter-party. There are several implementations and models for AMMs, featuring a variety of sophisticated economic mechanisms. We present a theory of AMMs. The core of our theory is an abstract operational model of the interactions between users and AMMs, which can be concretised by instantiating the economic mechanisms. We exploit our theory to formally prove a set of fundamental properties of AMMs, characterizing both structural and economic aspects. We do this by abstracting from the actual economic mechanisms used in implementations, and identifying sufficient conditions which ensure the relevant properties. Notably, we devise a general solution to the arbitrage problem, the main game-theoretic foundation behind the economic mechanisms of AMMs.
Despite the rapid spread of Internet of Things (IoT) systems, the lack of interoperability between the systems is significantly hindering their business and societal potential. Moreover, a major challenge for wider interoperability is that the IoT systems can be owned by multiple independent entities, whose collaboration will need to be organised to ensure their interoperability. One approach for achieving this is to establish federations supported by Distributed Ledger Technologies (DLTs), as this enables interoperability between entities and collaboration between business platforms, thereby overcoming many technical and administrative difficulties. DLTs can provide the required transparency and immutability for management of the federations, thus increasing trust and reducing the risk of misbehaviour that could destabilise the federation. This paper presents two system dynamics simulation models, which demonstrate that the success of a federation (with or without DLT support) is inversely related to the short-term selfishness of its members, and we then proceed to show that DLTs can improve the feedback received by the federation members on their actions by promoting a common consensus, which in turn can make the federation more resilient.
A well-governed DAO of DAOs can provide technological and community solutions for the evolution of the DAO ecosystem. Through its technological infrastructure designs, a DAO of DAOs can create, improve and expand well-functioning and well-governed networks of DAOs. That DAO infrastructure, in turn, improves most of the applications and uses of digital assets and decentralized commerce for the greater good of society. This article examines the core features of a possible DAO of DAOs design, its ability to expand the DAO ecosystem, and the design’s uses in business and society.
Decentralized Autonomous Organization (DAO) is very popular in Decentralized Finance (DeFi) applications as it provides a decentralized governance solution through blockchain. We analyze the governance characteristics in the Maker protocol, its stablecoin DAI and governance token Maker (MKR). To achieve that, we establish several measurements of centralized governance. Our empirical analysis investigates the effect of centralized governance over a series of factors related to MKR and DAI, such as financial, transaction, network and twitter sentiment indicators. Our results show that governance centralization influences both the Maker protocol, and the distribution of voting power matters. The main implication of this study is that centralized governance in MakerDAO very much exists, while DeFi investors face a trade-off between decentralization and performance of a DeFi protocol. This further contributes to the contemporary debate on whether DeFi can be truly decentralized.
Smart contracts are dependent on oracle systems for their adoption and usability. We perform an empirical study of oracle systems' usage trends and adoption metrics to provide better insight into the health of the smart contract ecosystem. We collect ChainLink usage data on the Ethereum network using a modified Ethereum client and running a full node. We analyze the collected data and present our findings and insights surrounding the usage trends, adoption metrics, oracle pricing and service quality associated with ChainLink on the Ethereum network.
Multiagent incentive contracts are advanced techniques for solving decentralized decision-making problems with asymmetric information. The principal designs contracts aiming to incentivize non-cooperating agents to act in his or her interest. Due to the asymmetric information, the principal must balance the efficiency loss and the security for keeping the agents. We prove both the existence conditions for optimality and the uniqueness conditions for computational tractability. The coupled principal-agent problems are converted to solving a Hamilton–Jacobi–Bellman equation with equilibrium constraints. Extending the incentive contract to a multiagent setting with history-dependent terminal conditions opens the door to new applications in corporate finance, institutional design, and operations research.
This article integrates existing theory from distributed computing and cryptology with gray literature from industry to provide a comprehensive description of the minimum requirements of a technological solution to the current ethics crisis in academic publishing. The paper argues that such a solution could significantly reduce the biases and misconduct that now exist in the academic peer review process. Theory suggests such a system could operate effectively as a distributed encrypted telecommunications network where nodes are anonymous, do not trust each other, with minimal central authority. To incentivize the academic community to join such a community, the paper proposes a new pseudo-cryptocurrency called litcoin (literature coin). This litcoin-based system would create economic scarcity based on proof of knowledge (POK), which is a synthesis of the proof of work (POW) mechanism used in bitcoin, and the proof of stake (POS) mechanism used in various altcoin communities.
Blockchain technologies make agreement among untrusted parties possible, without the need for certification authorities. Proposed frameworks have been put forward in sector as diverse as finance, health care, notary, intellectual property management, identity, provenance, international cooperation, social good, and security to cite but a few. Smart contracts, that is, self-enforcing agreements in terms of executable software running on blockchains, have been developed in several contexts. Such an under-definition computational model introduces innovative aspects, such as the economics and trust of the decentralized computation relying on the shared contribution of peers and their decentralized consensus. Following the first edition of the International Workshop on Future Perspectives of Decentralized APPlications, FPDAPP (held in conjunctions to EURO-PAR conference), this special issue primarily carries new results from revised and substantially extended versions of papers presented at the workshop. Moreover, this volume contains new contributions that rigorously explore and evaluate the potentiality of novel decentralized frameworks and applications. After a thorough peer-reviewing process focused on quality, innovative contribution, applicability to real-world scenarios, we have selected six manuscripts for publication. The paper “Analysis of multi-input multi-output transactions in the Bitcoin network” proposes an exploratory analysis on the Bitcoin network focused on mixing-like behaviors based on multi-input/output transactions. The article “Trusted systems of records based on Blockchain technology - a prototype for mileage storing in the automotive industry” proposes a blockchain-based trusted system of records to address the problem of asymmetric information on the used car market as described by Nobel laureate Akerlof. The paper “Blockchain applications beyond the cryptocurrency casino: The Punishment not Reward blockchain architecture” proposes an interesting punishment mechanism system as alternative to classical reward strategies for blockchain maintenance. The paper “Implementation and evaluation of smart contracts using a hybrid on- and off-blockchain architecture” introduces a novel hybrid architecture for the implementation of smart contracts, based on a centralized monitoring smart contract on the Ethereum blockchain. The paper “Design and practical implementation of verify-your-vote protocol” is focused on the highly debated and challenging problem of electronic voting. It proposes a verifiable blockchain-based online voting protocol that ensures security by using a variety of cryptographic primitives. Finally, the paper “Ensuring transparency and traceability of food local products: A blockchain application to a Smart Tourism Region” proposes a blockchain-oriented platform to guarantee the origin and provenance of food items in a Smart Tourism Region context where local food and beverage can become a good combination to attract tourist and to promote the area thanks to their clearly certified provenance. As guest editors, we would like to express our appreciation for the impressive contributions made by all authors. We would like also to thank all the reviewers that helped us to evaluate all submissions, providing valuable critics and suggestions to the authors. Finally, we would like to thank all editorial board members and all staff for allowing us to publish this Special Issue and for his great support throughout the entire publication process. The guest editors: Andrea Bracciali - University of Stirling Claudio Schifanella - University of Turin
In this contribution we extend an ontology for modelling agents and their interactions, called Ontology for Agents, Systems, and Integration of Services (in short, OASIS), with conditionals and ontological smart contracts (in short, OSCs). OSCs are ontological representations of smart contracts that allow to establish responsibilities and authorizations among agents and set agreements, whereas conditionals allow one to restrict and limit agent interactions, define activation mechanisms that trigger agent actions, and define constraints and contract terms on OSCs. Conditionals and OSCs, as defined in OASIS, are applied to extend with ontological capabilities digital public ledgers such as the blockchain and smart contracts implemented on it. We will also sketch the architecture of a framework based on the OASIS definition of OSCs that exploits the Ethereum platform and the Interplanetary File System.
In this contribution we extend an ontology for modelling agents and their interactions, called Ontology for Agents, Systems, and Integration of Services (in short, OASIS), with conditionals and ontological smart contracts (in short, OSCs). OSCs are ontological representations of smart contracts that allow to establish responsibilities and authorizations among agents and set agreements, whereas conditionals allow one to restrict and limit agent interactions, define activation mechanisms that trigger agent actions, and define constraints and contract terms on OSCs. Conditionals and OSCs, as defined in OASIS, are applied to extend with ontological capabilities digital public ledgers such as the blockchain and smart contracts implemented on it. We will also sketch the architecture of a framework based on the OASIS definition of OSCs that exploits the Ethereum platform and the Interplanetary File System.
Beyond an emerging popular web applications runtime supported in almost all commodity browsers, WebAssembly (WASM) is further regarded to be the next-generation execution environment for blockchain-based applications. Indeed, many popular blockchain platforms such as EOSIO and NEAR have adopted WASM-based execution engines. Most recently, WASM has been favored by Ethereum, the largest smart contract platform, to replace the state-of-the-art EVM. However, whether and how well current WASM outperforms EVM on blockchain clients is still unknown. This article conducts the first measurement study to understand the performance on WASM VMs and EVM for executing smart contracts for blockchain-based applications. To our surprise, the current WASM VM does not provide expected satisfactory performance. The overhead introduced by WASM is really non-trivial. Our results shed the light on challenges when deploying WASM in practice, and provide insightful implications for improvement space.
As the most popular blockchain that supports smart contracts, there are already more than 296 thousand kinds of cryptocurrencies built on Ethereum. However, not all cryptocurrencies can be controlled by users. For example, some money is permanently locked in wallets' accounts due to attacks. In this paper, we conduct the first systematic investigation on locked cryptocurrencies in Ethereum. In particular, we define three categories of accounts with locked cryptocurrencies and develop a novel tool named CLUE to discover them. Results show that there are more than 216 million dollars value of cryptocurrencies locked in Ethereum. We also analyze the reasons (i.e., attacks/behaviors) why cryptocurrencies are locked. Because the locked cryptocurrencies can never be controlled by users, avoid interacting with the accounts discovered by CLUE and repeating the same mistakes again can help users to save money.
Jaydeep Deshpande, M.M. Shankare Gowda, Manish Dixit, M S Khubbar · 6 authors
Hundreds of public procurement projects are undertaken every day all over the country. The tenders for these projects are given to the winning contractor in an auction-like setting which have massive security issues. After a contractor wins a tender, the specifics of the progress of the work done are rarely properly monitored. The details of the finances spent on the project can be easily manipulated. To enable integrity, non-repudiation and immutability to the data requires the desirable technology to support the above requirements. Hence, the proposed system uses blockchain technology to provide transparency and trust to all parties involved in the network. The entire system consists of two modules such as the Tender Bidding system and Tender Monitoring system using a multi-organization blockchain network in the Hyperledger Fabric. The whole bidding process is improved by creating a decentralized descending auction system that will carry it out fairly and transparently. The Tender Monitoring system employs a custom endorsement policy to attain 100% consensus for attesting every transaction made regarding the progress of the project so that vital steps are ratified and recorded with evidence supporting their integrity. The main aspects of the system, its many components, deployment and drawbacks are viewed.
Industrial Symbiosis can evolve from a simple concept to a revolutionary practical approach where prosumer companies produce goods and provide services through automated negotiation of Smart Contracts by means of new technologies like Internet-of-Things (IoTs) and Blockchain in a Peer-to-Peer (P2P) Market. However, a symbiotic scheme of prosumers exchanging utility surpluses and industrial services gives rise to a great challenge: each company will only participate in the market if the motivation of increasing its own profits exists. I n t his work, each prosumer company is represented by a software agent that resorts to previously learned context-aware strategies for defining prior distributions. Then, strategies are adapted to different opponents when negotiating utility contracts by properly accounting for opponents’ preferences (private) and key contextual (public) information. Agents negotiating Smart Contracts can be readily implemented using Distributed Applications (dApps) over Ethereum/Solidity and digital currencies as the Ether.
Blockchain technology has gained wide acceptance in recent years. Smart contracts facilitate the application of the blockchain technology. Smart contracts are programs running distributed environments and are thus error prone. Smart contracts often lack precise specifications and are written in high-level programming languages such as Solidity. In this paper, we present an approach to formally model and analyze smart contracts using predicate transitions nets. We use the blind auction smart contract to demonstrate our approach, which reveals some problematic implementation of some smart contract functions. We have applied predicate transition nets in modeling and analyzing all 11 smart contracts in Azure blockchain workbench. Although we cannot tell whether there is any problem in these smart contracts based on their informal descriptions and Solidity programs without designer input. Our experience has shown the applicability and suitability of predicate transition nets. We believe that our approach can help smart contract designers to detect and prevent early design problems in the current practice of using informal textual descriptions of smart contracts.
Gerald B. Imbugwa, Manuel Mazzara, Salvatore Distefano
Abstract In this paper, we envision to illustrate the process to be used in developing a mobile application on the smart contract. We start by looking at what other researchers have accomplished and how we can improve on what already exists. The paper highlights the requirement gathering process, the methodology for data collection to streamline and validate the requirement, the architecture and implementation phase by analyzing the technological stack to achieve the business goal.
EIP-1559 is a proposal to make several tightly coupled additions to\nEthereum's transaction fee mechanism, including variable-size blocks and a\nburned base fee that rises and falls with demand. This report assesses the\ngame-theoretic strengths and weaknesses of the proposal and explores some\nalternative designs.\n
Decentralized Autonomous Organization (DAO) is believed to play a significant role in our future society governed in a decentralized way. In this article, we first explain the definitions and preliminaries of DAO. Then, we conduct a literature review of the existing studies of DAO published in the recent few years. Through the literature review, we find out that a comprehensive survey towards the state-of-the-art studies of DAO is still missing. To fill this gap, we perform such an overview by identifying and classifying the most valuable proposals and perspectives closely related to the combination of DAO and blockchain technologies. We anticipate that this survey can help researchers, engineers, and educators acknowledge the cutting-edge development of blockchain-related DAO technologies.