Kobelt, MaxMaxKobeltSober, Michael PeterMichael PeterSoberSchulte, StefanStefanSchulteRometsch, LeandroLeandroRometsch2026-01-142026-01-142025-117th Conference on Blockchain Research & Applications for Innovative Networks and Services, BRAINS 2025https://hdl.handle.net/11420/60881Blockchain Interoperability Solutions (BISs) enable seamless communication and transactions between two or more blockchains. These solutions form an additional heterogeneous set on top of the blockchain layer and impose new constraints on cross-blockchain communication. This new interconnected network of blockchains can provide different communication routes, resulting in the need to find an optimal route between the source and target blockchains. In this paper, we aim to foster discussion about the problems and opportunities that the widescale adoption of BISs brings. We define the problem of using multiple BISs to route cross-blockchain communication and develop theoretical foundations for cross-blockchain routing. Based on the formalization, we implement and evaluate an algorithm that returns an optimal route for a communication request, given a network of blockchains and user-defined objectives.enBlockchain interoperabilitycross-blockchain communicationroutingComputer Science, Information and General Works::005: Computer Programming, Programs, Data and Security::005.7: DataConference Paper10.1109/brains67003.2025.11302933Conference Paper