@article {2026:fc4mc:jbcra,
	title = {Enhancing Transparency in Transaction Ordering: Dynamic Orderer Selection in Blockchain-driven Collaborative Processes},
	journal = {Blockchain: Research and Applications},
	year = {In Press},
	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.},
	author = {Hassan Atwi and Tom Lichtenstein and Cesare Pautasso and Mathias Weske}
}
@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}
}
@inproceedings {wesoa2015,
	title = {From Choreography Diagrams to RESTful Interactions},
	year = {2015},
	month = {November},
	publisher = {Springer},
	address = {Goa, India},
	abstract = {Today, business process management is a key approach to organize work, and many companies represent their operations in business process models. Recently, choreography diagrams have been introduced to represent interactions between business processes, run by different partners. While there is considerable work on using process models during process implementation, there is little work on using choreography models to implement interactions between business processes. In this paper, a novel approach to enhance choreography diagrams by execution information is introduced. The approach is based on the REST architecture style, which is the primary way for interacting systems. Using enhanced choreography diagrams allows us to develop REST-based interactions among business partners in an efficient manner. The approach is illustrated by an example of an accommodation reservation service.},
	keywords = {BPMN Choreography, RESTful conversation},
	author = {Adriatik Nikaj and Sankalita Mandal and Cesare Pautasso and Mathias Weske}
}
