Blockchain Papers

Xuefei Wang, Haojie Li, Jie Liu, Dongfang Wu · 5 authors

No abstract is available for this record.

Eduard Babkin, Vitalii Golov, Pavel Malyzhenkov

No abstract is available for this record.

Paul van Vulpen, Slinger Jansen

No abstract is available for this record.

Jinlong He, Yang Liu, Jingwen Chen, Peng Song · 6 authors

Blockchain, as a distributed ledger technology that can establish trust in untrusted environments, has garnered increasing attention in recent years. Enhancing system performance by improving the concurrency of blockchain systems is a current research focus. However, at the same time, the high transaction abortion rate in high-concurrency scenarios has become a new urgent problem to be solved. In this article, our primary focus lies in addressing the issue of high transaction abort rates in Hyperledger Fabric within concurrent scenarios. We propose MoryFabric, a conflict transaction optimization scheme based on transaction actual validity verification and reordering based on keys. Through solutions involving inter-block transaction conflict detection, transaction actual validity detection, and key-based transaction reordering, we aim to minimize transaction abort rates to the greatest extent possible. We integrate the proposed solution into Hyperledger Fabric.Benchmark tests using SmallBank indicate that in scenarios characterized by a high number of conflicting transactions, the proposed approach effectively reduces the average transaction abort rate and exhibits favorable latency performance.

Julius Köpke, Sebastian Trattnig

Blockchains and distributed ledger technology offer promising capabilities for supporting collaborative business processes across organizations. Typically, approaches in this field fall into two categories: either executing the entire process model on the blockchain or using the blockchain primarily to enforce or monitor the exchange of messages between participants. Our work proposes a novel approach that sits between these two methods. We introduce a centralized process model extended with blockchain annotations, detailing the tasks of each participating organization and the extent to which blockchain technology is needed to secure task execution. This model also includes all critical data objects and specifies how their handling should be protected by the blockchain. This technical report outlines a systematic three-step method for automatically decentralizing this comprehensive model into individual local process models for each organization, coupled with a separate process model for the blockchain. This decentralized structure effectively replicates the original global process model. Our transformation approach is rule-based, focusing on creating a platform-inde-pendent model first, then a platform-specific model. Subsequently, we project the platform-specific model to obtain one model for the blockchain and one model for each participating organization.

Juanjuan Li, Xiaolong Liang, Rui Qin, Fei–Yue Wang

As the key component of the emerging Web3, Decentralized Autonomous Organizations and Operations (DAOs) enables decentralized decision-making and governance mainly driven by blockchain and smart contracts. This paper first provides a comprehensive examination of DAOs’ evolution, tracing their historical development and the progression of their definitions and underlying concepts. Then, it presents their classical governance models founded on token economics and analyzes typical practical cases, subsequently identifying the current dilemmas faced by DAO governance. To address these dilemmas, TRUE Autonomous Organizations and Operations (TAOs) are proposed, which underscores the trustable, reliable, usable, efficient and effective essence of decentralization. Besides, the distinctions between TAOs and DAOs are discussed from perspective of the value systems, governance structures, incentive allocation, decision-making model. Furthermore, it highlights the research issues that need to be addressed to realize the full potential of TAOs.

Zi Wang, Keming Wang

The international railway logistics management system with a centralized system has problems such as information security, difficulty tracking logistics information, complex operating procedures, and information sharing and exchange. However, the decentralized, tamper-proof, and traceable features of blockchain technology can effectively enhance the data security and credibility of the system. Nonetheless, the development of smart contracts based on blockchain lacks a disciplined, standardized, and mature development process. On the other hand, adopting a Model-Driven Architecture (MDA) development approach can reduce human coding errors and improve development efficiency. This study proposed a modeling method based on UML class diagrams and state machine diagrams to analyze the static structure and dynamic behavior of the smart contract in the international railway logistics management system. By developing a conversion algorithm and combining the source and target metamodels, the platform-independent model (PIM) was converted into a platform-specific model (PSM), which was eventually transformed into code using a model-to-code transformation algorithm. The feasibility and correctness of this method were validated through experiments.

Liguan Wang, Yuan Li, Haibin Kan

No abstract is available for this record.

Simone Casale Brunet, Marco Mattavelli

This article conducts an extensive examination of the persisting challenges related to smart contract attacks within blockchain networks, with a particular focus on the reentrancy attack. It emphasizes the inherent vulnerabilities embedded in the programming languages commonly employed for smart contract development, particularly within Ethereum Virtual Machine (EVM)-based blockchains. While the concrete example used primarily employs the Solidity programming language, the insights garnered from this study are readily generalizable to a wide array of blockchain architectures. Significantly, this article extends beyond the mere identification of vulnerabilities and ventures into the realm of proactive security measures. It explores the adaptation and adoption of dataflow programming paradigms, employing Domain-Specific Languages (DSLs) to enforce security by design in the context of smart contract development. This forward-looking approach aims to bolster the foundational principles of blockchain security, offering a promising research direction for mitigating the risks associated with smart contract vulnerabilities. The objective of this article is to cater to a diverse audience, ranging from individuals with limited computer science and programming expertise to seasoned experts in the field. It provides a comprehensive and accessible resource for fostering a deeper understanding of the intricate dynamics between blockchain technology and the imperative need for secure smart contract development practices.

Shengyue Yao, Jingru Yu, Yi Yu, Xu Jia · 8 authors

With a growing complexity of the intelligent traffic system (ITS), an integrated control of ITS that is capable of considering plentiful heterogeneous intelligent agents is desired. However, existing control methods based on the centralized or the decentralized scheme have not presented their competencies in considering the optimality and the scalability simultaneously. To address this issue, we propose an integrated control method based on the framework of Decentralized Autonomous Organization (DAO). The proposed method achieves a global consensus on energy consumption efficiency (ECE), meanwhile to optimize the local objectives of all involved intelligent agents, through a consensus and incentive mechanism. Furthermore, an operation algorithm is proposed regarding the issue of structural rigidity in DAO. Specifically, the proposed operation approach identifies critical agents to execute the smart contract in DAO, which ultimately extends the capability of DAO-based control. In addition, a numerical experiment is designed to examine the performance of the proposed method. The experiment results indicate that the controlled agents can achieve a consensus faster on the global objective with improved local objectives by the proposed method, compare to existing decentralized control methods. In general, the proposed method shows a great potential in developing an integrated control system in the ITS.

Vimal Dwivedi, Mubashar Iqbal, Alex Norta, Raimundas Matulevičius

Blockchain governs inter-organizational business processes and enables decentralized autonomous organizations (DAO) with governance capabilities via smart contracts (SC). Due to the programmer’s lack of prior knowledge of the contract domain, SCs are ambiguous and error-prone. Several works, i.e., SPESC, Symboleo, and SmaCoNat, exist to support the legally-binding SCs. The aforementioned SCLs present intriguing approaches to building legally-binding SCs but either lack domain completeness, or are intended for non-collaborative business processes. In our previous work, we address the above-mentioned shortcomings of the XML-based smart-legal-contract markup language (SLCML), in which blockchain developers focus on the contractual workflow rather than the syntax specifics. However, SLCML, as a blockchain-independent formal specification language, is not evaluated to determine its applicability, usefulness, and usability for establishing legally-binding SCs for workflow enactment services (WES) to automate and streamline the business processes within connected organizations. In accordance with this, we formally implement the SLCML and propose evaluation approaches, such as running case and lab experiments, to demonstrate the SLCML’s generality and applicability for developing legally-binding SCs. Overall, the results of this work ascertain the applicability, usefulness, and usability of the proposed SLCML for establishing legally-binding SCs for WES.

Julião Braga, Francisco Regateiro, Itana Stiubiener, Juliana Cristina Braga

This work presents a manually built ontology to aggregate and knowledge systematization of Decentralized Autonomous Organizations (DAOs) obtained from web pages. An ontology is a formal description of knowledge as a set of concepts within a domain and the relationships between them, providing a common vocabulary for researchers to share information. Ontology construction from text involves analyzing collected text, identifying relevant terms and concepts, and representing the ontology using representation languages such as OWL, RDF, or RDFS. Manual ontology construction can be performed using applications such as Protege. This work describes the methodology used, how to use the ontology created through Protege using SPARQL, and presents future work proposals, including creating the same ontology using Deep Learning from Machine Learning techniques.

Marina Shevko, Yury Yanovich, Darya Zhukova

Decentralized autonomous organizations (DAOs) offer transparency and integrity in decision-making, but their decentralized structure presents challenges during times of crisis. Our paper implements and demonstrates a solution to this issue by introducing a quasi DAO (qDAO) that allows for centralized decision-making when necessary. By modifying smart contracts and introducing new rules, we strike a balance between decentralization and centralized management, offering potential opportunities for improved crisis management in DAOs. We present a demo of our qDAO implementation on the local Ethereum testnet, along with a web application for user input. Our approach expands the possibilities of DAO administrator control while maintaining the integrity and auditability of DAO operations.

Behrouz Sefid‐Dashti, Javad Salimi Sartakhti, Hassan Daghigh

Blockchain has received attention for its potential use in business. Bitcoin is powered by blockchain, and interest in it has surged in the past few years. It has many uses that need to be modeled. Modeling is used in many walks of life to share ideas, reduce complexity, achieve close alignment of one person viewpoint with another and provide abstractions of a system at some level of precision and detail. Software modeling is used in Model Driven Engineering (MDE), and Domain Specific Languages (DSLs) ease model development and provide intuitive syntax for domain experts. The present study has designed and evaluated a meta-model for the bitcoin application domain to facilitate application development and help in truly understanding bitcoin. The proposed meta-model, including stereotypes, tagged values, enumerations and a set of constraints defined by Object Constraint Language (OCL), was defined as a Unified Modeling Language (UML) profile and was implemented in the Sparx Enterprise Architect (Sparx EA) modeling tool. A case study developed by our meta-model is also presented.

Zineb Lamghari

In a distributed peer-to-peer network, blockchain technology enables the secure transmission of digital assets.This is done based on intellectual agreement capabilities.Indeed, blockchain world has developed into a tool for managing transversal processes on an unbiased platform.Process mining has evolved as a well-known toolkit for comprehending different organization processes.Recently, researchers developed strategies for resolving the issue of collecting reliable data gathered from blockchains in order to improve the examination of blockchain applications employing process mining.There is yet to be a clear assessment of the utility of process mining on public blockchain event logs.In this paper, we will validate the applicability of process mining on public blockchain event logs by treating ChickenHunt data set.ChickenHunt is a competitive game that is operated as a Decentralized application on Ethereum blockchain network.

Leyla Moctar M’Baba, Nour Assy, Mohamed Sellami, Walid Gaaloul · 5 authors

No abstract is available for this record.

Prashant Agrawal, Abhinav Nakarmi, Mahavir Prasad Jhawar, Subodh Sharma · 5 authors

We introduce the notion of \emph{traceable mixnets}. In a traditional mixnet, multiple mix-servers jointly permute and decrypt a list of ciphertexts to produce a list of plaintexts, along with a proof of correctness, such that the association between individual ciphertexts and plaintexts remains completely hidden. However, in many applications, the privacy-utility tradeoff requires answering some specific queries about this association, without revealing any information beyond the query result. We consider queries of the following types: a) given a ciphertext in the mixnet input list, whether it encrypts one of a given subset of plaintexts in the output list, and b) given a plaintext in the mixnet output list, whether it is a decryption of one of a given subset of ciphertexts in the input list. Traceable mixnets allow the mix-servers to jointly prove answers to the above queries to a querier such that neither the querier nor a threshold number of mix-servers learn any information beyond the query result. Further, if the querier is not corrupted, the corrupted mix-servers do not even learn the query result. We first comprehensively formalise these security properties of traceable mixnets and then propose a construction of traceable mixnets using novel distributed zero-knowledge proofs (ZKPs) of set membership and of a statement we call reverse set membership. Although set membership has been studied in the single-prover setting, the main challenge in our distributed setting lies in making sure that none of the mix-servers learn the association between ciphertexts and plaintexts during the proof. We implement our distributed ZKPs and show that they are faster than state-of-the-art by at least one order of magnitude.

Mojtaba Eshghie, Cyrille Artho, Hans Stammler, Wolfgang Ahrendt · 6 authors

Logical flaws in smart contracts are often exploited, leading to significant financial losses. Our tool, HighGuard, detects transactions that violate business logic specifications of smart contracts. HighGuard employs dynamic condition response (DCR) graph models as formal specifications to verify contract execution against these models. It is capable of operating in a cross-chain environment for detecting business logic flaws across different blockchain platforms. We demonstrate HighGuard's effectiveness in identifying deviations from specified behaviors in smart contracts without requiring code instrumentation or incurring additional gas costs. By using precise specifications in the monitor, HighGuard achieves detection without false positives. Our evaluation, involving 54 exploits, confirms HighGuard's effectiveness in detecting business logic vulnerabilities. Our open-source implementation of HighGuard and a screencast of its usage are available at: https://github.com/mojtaba-eshghie/HighGuard https://www.youtube.com/watch?v=sZYVV-slDaY

Tianhong Xiong, Shangqing Feng, Maolin Pan, Yang Yu

Summary Currently, inter‐organizational process collaboration (IOPC) has been widely used in the design and development of distributed systems that support business process execution. Blockchain‐based IOPC can establish trusted data sharing among participants, attracting more and more attention. The core of such study is to translate the graphical model (e.g., BPMN) into program code called smart contract that can be executed in the blockchain environment. In this context, a proper smart contract plays a vital role in the correct implementation of block‐chain‐based IOPC. In fact, the quality of graphical model affects the smart contract generation. Problematic models (e.g., deadlock) will result in incorrect contracts (causing unexpected behaviors). To avoid this undesired implementation, this article explores to generate smart contracts by using the verified formal model as input instead of graphical model. Specifically, we introduce a prototype framework that supports the automatic generation of smart contracts, providing an end‐to‐end solution from modeling, verification, translation to implementation. One of the cores of this framework is to provide a CSP#‐based formalization for the BPMN collaboration model from the perspective of message interaction. This formalization provides precise execution semantics and model verification for graphical models, and a verified formal model for smart contract generation. Another novelty is that it introduces a syntax tree‐based translation algorithm to directly map the formal model into a smart contract. The required formalism, verification, and translation techniques are transparent to users without imposing additional burdens. Finally, a set of experiments shows the effectiveness of the framework.

Konstantinos Tsiounis, Kostas Kontogiannis

We are currently witnessing the proliferation of blockchain environments to support a wide spectrum of corporate applications through the use of smart contracts. It is of no surprise that smart contract programming language technology constantly evolves to include not only specialized languages such as Solidity, but also general purpose languages such as GoLang and JavaScript. Furthermore, blockchain technology imposes unique challenges related to the monetary cost of deploying smart contracts, and handling roll-back issues when a smart contract fails. It is therefore evident that the complexity of systems involving smart contracts will only increase over time thus making the maintenance and evolution of such systems a very challenging task. One solution to these problems is to approach the implementation and deployment of such systems in a disciplined and automated way. In this paper, we propose a model-driven approach where the structure and inter-dependencies of smart contract, as well as stakeholder objectives, are denoted by extended goal models which can then be transformed to yield Solidity code that conforms with those models. More specifically, we present first a Domain Specific Language (DSL) to denote extended goal models and second, a transformation process which allows for the Abstract Syntax Trees of such a DSL program to be transformed into Solidity smart contact source code. The transformation process ensures that the generated smart contract skeleton code yields a system that is conformant with the model, which serves as a specification of said system so that subsequent analysis, understanding, and maintenance will be easier to achieve.

Jaime Garcia Represa, Jerker Delsing

No abstract is available for this record.

Balaźs Ádám Toldi, Imre Kocsis

Business process collaboration between independent parties is challenging when participants do not completely trust each other. Tracking actions and enforcing the activity authorizations of participants via blockchain-hosted smart contracts is an emerging solution to this lack of trust, with most state-of-the-art approaches generating the orchestrating smart contract logic from Business Process Model and Notation (BPMN) models. However, compared to centralized business process orchestration services, smart contract state typically leaks potentially sensitive information about the state of the collaboration, limiting the applicability of decentralized process orchestration. This paper presents a novel, collaboration confidentiality-preserving approach where the process orchestrator smart contract only stores encrypted and hashed process states and validates participant actions against a BPMN model using zero-knowledge proofs. We cover a subset of BPMN, which is sufficient from the practical point of view, support messagepassing between participants, and provide an open-source, endto-end prototype implementation that automatically generates the key software artifacts.

Mojtaba Eshghie, Wolfgang Ahrendt, Cyrille Artho, Thomas Hildebrandt · 5 authors

Smart contracts manage blockchain assets and embody business processes. However, mainstream smart contract programming languages such as Solidity lack explicit notions of roles, action dependencies, and time. Instead, these concepts are implemented in program code. This makes it very hard to design and analyze smart contracts. We argue that DCR graphs are a suitable formalization tool for smart contracts because they explicitly and visually capture the mentioned features. We utilize this expressiveness to show that many common high-level design patterns representing the underlying business processes in smart contract applications can be naturally modeled this way. Applying these patterns shows that DCR graphs facilitate the development and analysis of correct and reliable smart contracts by providing a clear and easy-to-understand specification.

Yuming He, Wenzhuo Li

NFTs are a groundbreaking application of blockchain technology that allows for the ownership and trading of unique digital assets. From artwork and collectibles to virtual real estate and gaming items, NFTs have taken the world by storm, capturing the attention of enthusiasts and investors alike.