Please note: This master’s thesis presentation will take place in DC 2314.
Amin Rezaei, Master’s candidate
David R. Cheriton School of Computer Science
Supervisor: Professor Bernard Wong
Demand for blockchain applications has led to a surge of new public blockchains. However, this fragments liquidity and pushes users to bridge across unfamiliar protocols, increasing risk and complexity. Cross-chain communication enables interoperability, allowing contracts to execute logic and move assets across chains. Yet current delivery solutions either support message passing only between directly connected chains, limiting connectivity, or are centralized and route through a single hub chain that introduces a single point of failure and requires trust in the hub operator. Inter-blockchain communication can become more robust by leveraging concepts from traditional network architectures, including routing, name resolution, and policy-based message delivery.
This thesis studies the problem of policy-driven cross-chain routing: Current cross-chain routing is largely ad-hoc and manual, and does not reliably respect users’ security or cost preferences when no direct connection exists. Given a dynamic inter-chain topology and user policies (e.g., security thresholds, fee budgets, latency targets), we compute routes over multi-hop Inter-Blockchain Communication (IBC) while ensuring security constraints are strictly enforced on-chain and preference constraints are met with practical guarantees. We present a modular stack and three routing methods (Single-Relayer, zkRouter, Relayer Network). Our evaluation shows near 90% connectivity vs. 15% for hub-and-spoke, less than $0.10 on-chain cost per message, and scales to more than 10^6 messages maintaining low processing time, while preserving IBC’s security assumptions and without significant fee overhead.