@article {2026:fc4mc:jbcra,
	title = {Enhancing Transparency in Transaction Ordering: Dynamic Orderer Selection in Blockchain-driven Collaborative Processes},
	journal = {Blockchain: Research and Applications},
	year = {2025},
	chapter = {100412},
	abstract = {Supporting decentralized and trustless coordination among organizations, blockchain technology holds significant potential for addressing trust-related issues in inter-organizational collaborative processes. In this context, basic blockchain consensus mechanisms often introduce vulnerabilities, such as transaction reordering, manipulation, or censorship by malicious nodes, which can distort business objectives and undermine trust among collaborators.
This paper examines the influence of transaction ordering on decentralized business process choreography, highlighting competitive scenarios where malicious ordering can create unfair advantages. To counter such maximal extractable value attacks, we propose to align transaction ordering with business process logic with three novel strategies for process-aware transaction ordering. Our approach has proven effective in mitigating malicious transaction ordering, thereby enhancing fairness and transparency in the collaborative process execution. However, this comes with a trade-off in terms of time and computational cost, as observed in our extensive experimental evaluation.},
	keywords = {Block selection, blockchain, Process choreography, Transaction ordering Transparency},
	doi = {10.1016/j.bcra.2025.100412},
	author = {Hassan Atwi and Tom Lichtenstein and Cesare Pautasso and Mathias Weske}
}
@article {2025:tplop,
	title = {An Extended Pattern Collection for Blockchain-Based Applications},
	journal = {Transactions on Pattern Languages of Programming (TPLOP)},
	volume = {14630},
	year = {2025},
	month = {March},
	pages = {67{\textendash}117},
	abstract = {Blockchain is an emerging technology that enables new forms of decentralized software architectures, where distributed components
can reach agreements on shared system states without trusting a central integration point. Blockchain provides a shared infrastructure to execute
programs, called smart contracts, and to store data. Since blockchain technologies are at an early stage, there is a lack of a systematically organized knowledge providing a holistic view on designing software systems that use blockchain. We view blockchain as a component of a bigger software system, which requires patterns for using blockchain in the design of the software architecture. In this paper, we collect a list of patterns for blockchain-based applications. The pattern collection is categorized into five categories, including interaction with external world patterns, data
management patterns, security patterns, structural patterns of contracts, and user interaction patterns. Some patterns are designed considering the nature of blockchain and how blockchains can be specifically introduced within real-world applications. Others are variants of existing design patterns applied in the context of blockchain-based applications and smart contracts.},
	keywords = {blockchain, patterns},
	doi = {10.1007/978-3-662-70810-1_2},
	url = {https://arxiv.org/abs/2502.16017},
	author = {Xiwei Xu and Cesare Pautasso and Sin Kuang Lo and Liming Zhu and Qinghua Lu and Ingo Weber}
}
@inproceedings {2025:fc4mc:dlt4bpm,
	title = {Gas Management Patterns in Blockchain-enabled Process Execution},
	year = {2025},
	month = {September},
	publisher = {Springer},
	address = {Seville, Spain},
	abstract = {In this paper, we present a methodology for modeling efficient gas management in blockchain-enabled collaborative business processes. We introduce four patterns designed to optimize and manage gas fees throughout business process execution. These patterns are formally represented using BPMN to provide a clear visual framework for integration into business workflows. Furthermore, we translate these patterns into Solidity smart contracts and evaluate their performance within a real-world business scenario. Our approach aims to enhance the efficiency and cost-effectiveness of blockchain-based process execution.},
	keywords = {blockchain, BPMN, Collaborative processes, Gas Management, Solidity},
	url = {https://dlt4bpm.github.io/assets/papers/BPM_2025_paper_348.pdf},
	author = {Hassan Atwi and Cesare Pautasso}
}
@proceedings {2024:fc2mc:bpm,
	title = {Transparent Transaction Ordering in Blockchain-based Collaborative Processes},
	year = {2024},
	month = {September},
	publisher = {Springer},
	address = {Krakow, Poland},
	abstract = {Blockchain technology offers a promising solution for overcoming trust-related challenges, such as transparency in interorganizational collaborative processes. However, since the ordering of transactions in a block can affect the outcome of a process instance, fairness and transparency concerns regarding block selection may arise. This paper presents a consensus-agnostic approach to promote transparency in transaction ordering in blockchain-based business processes. The approach allows participants to align the execution order of their transactions with their business objectives, effectively mitigating the lack of transparency associated with the arbitrary selection and ordering of transactions during block selection. Our experiments reveal that the increased transparency mitigates the risks of suppression and displacement attacks at the cost of introducing additional latency and cost.},
	keywords = {Block selection, blockchain, choreography, Transaction ordering, Transparency},
	author = {Hassan Atwi and Tom Lichtenstein and Cesare Pautasso and Mathias Weske}
}
@conference {fc4mc:2023:bpm,
	title = {Loose Collaborations on the Blockchain: Survey and Challenges},
	booktitle = {21st International Conference on Business Process Management - Blockchain Forum},
	year = {2023},
	month = {September},
	pages = {21--35},
	publisher = {Springer},
	organization = {Springer},
	address = {Utrecht, the Netherlands},
	abstract = {Blockchain technology has emerged as a promising infrastructure for enabling collaboration between mutually distrustful organizations. The enactment of blockchain-based collaborative processes typically requires a profound understanding of the process being executed, limiting support for flexible processes that cannot be fully prespecified at design time. To overcome this limitation, support for looseness, dealing with the configuration and execution of underspecified processes, is essential. In this paper, we conduct a systematic literature review to examine looseness support for blockchain-based collaborative processes from a behavioral and organizational perspective. In addition, we identify open research challenges to pave the way for further research in this area.},
	keywords = {blockchain, Collaborative processes, Flexibility, Looseness},
	doi = {10.1007/978-3-031-43433-4_2},
	url = {https://link.springer.com/chapter/10.1007/978-3-031-43433-4_2},
	author = {Tom Lichtenstein and Hassan Atwi and Mathias Weske and Cesare Pautasso}
}
@conference {2018:blockchain:europlop,
	title = {A Pattern Collection for Blockchain-based Applications},
	booktitle = {23rd European Conference on Pattern Languages of Programs (EuroPLoP)},
	year = {2018},
	month = {July},
	publisher = {ACM},
	organization = {ACM},
	address = {Kloster Irrsee, Germany},
	abstract = {Blockchain is an emerging technology that enables new forms of decentralized software architectures, where distributed components can reach agreements on shared system states without trusting a central integration point. Blockchain provides a shared infrastructure to execute programs, called smart contracts, and to store data. Since blockchains are at an early stage, there is a lack of a systematic and holistic view on designing software systems that use blockchain. We view blockchain as part of a bigger system, which requires patterns of using blockchain in the design of the bigger systems. In this paper, we collect a list of patterns for blockchain-based applications. The pattern collection is categorized into four types, including interaction with external world patterns, data management patterns, security patterns and contract structural patterns. Some patterns are designed specifically based on real-world blockchain-based applications considering the nature of blockchain. Others are variants of existing design patterns applied in the context of blockchain-based applications and smart contracts.},
	keywords = {blockchain, patterns},
	doi = {10.1145/3282308.3282312},
	url = {https://dl.acm.org/citation.cfm?id=3282312},
	author = {Xiwei Xu and Cesare Pautasso and Liming Zhu and Qinghua Lu and Ingo Weber}
}
@conference {2017:icsa:blockchain,
	title = {A Taxonomy of Blockchain-based Systems for Architecture Design},
	booktitle = {1st IEEE International Conference on Software Architecture (ICSA 2017)},
	year = {2017},
	month = {April},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Gothenburg, Sweden},
	abstract = {Blockchain is an emerging technology for decentralised and transactional data sharing across a large network of untrusted participants. It enables new forms of distributed software architectures, where agreement on shared states can be established without trusting a central integration point. A major difficulty for architects designing applications based on blockchain is that the technology has many configurations and variants. Since blockchains are at an early stage, there is little product data or reliable technology evaluation available to compare different blockchains. In this paper, we propose how to classify and compare blockchains and blockchain-based systems to assist with the design and assessment of their impact on software architectures. Our taxonomy captures major architectural characteristics of blockchains and the impact of their principal design decisions. This taxonomy is intended to help with important architectural considerations about the performance and quality attributes of blockchain-based systems.},
	keywords = {blockchain, software architecture},
	author = {Xiwei Xu and Ingo Weber and Liming Zhu and Mark Staples and Jan Bosch and Len Bass and Cesare Pautasso and Paul Rimba}
}
@conference {blockchain:2016:wicsa,
	title = {The Blockchain as a Software Connector},
	booktitle = {13th Working IEEE/IFIP Conference on Software Architecture (WICSA 2016)},
	year = {2016},
	month = {April},
	address = {Venice, Italy},
	abstract = {Blockchain is an emerging technology for decentralized and transactional data sharing across a large network of untrusted participants. It enables new forms of distributed software architectures, where components can find agreements on their shared states without trusting a central integration point or any particular participating components. Considering the blockchain as a software connector helps make explicitly important architectural considerations on the resulting performance and quality attributes (for example, security, privacy, scalability and sustainability) of the system. Based on our experience in several projects using blockchain, in this paper we provide rationales to support the architectural decision on whether to employ a decentralized blockchain as opposed to other software solutions, like traditional shared data storage. Additionally, we explore specific implications of using the blockchain as a software connector including design trade-offs regarding quality attributes.},
	keywords = {blockchain, software connector},
	author = {Xiwei Xu and Cesare Pautasso and Liming Zhu and Vincent Gramoli and Alexander Ponomarev and An Binh Tran and Shiping Chen}
}
