Towards Policy-Enabled Multi-Hop Routing for Cross-Chain Message Delivery

TL;DR

This paper presents xRoute, a decentralized cross-chain routing framework that enhances connectivity, security, and scalability in blockchain message delivery without relying on centralized hubs.

Contribution

It introduces a policy-enabled routing system inspired by traditional networks, allowing customizable, verifiable, and decentralized cross-chain communication.

Findings

Improves connectivity and decentralization over hub-based solutions.

Enhances scalability under heavy load conditions.

Enables verification of routing policies for security.

Abstract

Blockchain ecosystems face a significant issue with liquidity fragmentation, as applications and assets are distributed across many public chains with each only accessible by subset of users. Cross-chain communication was designed to address this by allowing chains to interoperate, but existing solutions limit communication to directly connected chains or route traffic through hubs that create bottlenecks and centralization risks. In this paper, we introduce xRoute, a cross-chain routing and message-delivery framework inspired by traditional networks. Our design brings routing, name resolution, and policy-based delivery to the blockchain setting. It allows applications to specify routing policies, enables destination chains to verify that selected routes satisfy security requirements, and uses a decentralized relayer network to compute routes and deliver messages without introducing a trusted hub. Experiments on the chains supporting the Inter-Blockchain Communication (IBC) protocol show that our approach improves connectivity, decentralization, and scalability compared to hub-based designs, particularly under heavy load.