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.