Publication Type

Conference Proceeding Article

Version

acceptedVersion

Publication Date

4-2025

Abstract

Payment channels are a cornerstone of a scalable blockchain infrastructure that enables transacting parties to lock assets on the blockchain and perform rapid off-chain updates with minimal latency and overhead. These protocols dramatically reduce on-chain interaction and improve throughput, with blockchain consensus only invoked in the event of disputes or final closure. While widely adopted in single-chain settings—such as in the Lightning Network for Bitcoin—existing constructions have several limitations, in particular they suffer from at least one of the following limitations: 1. No cross-chain. They do not enable fast trading of assets that reside on multiple isolated blockchains. 2. Non-optimal round complexity. The off-chain round complexity is not optimal (i.e., parties require more than two rounds to update the channel). 3. No bitcoin compatibility. They require a more advanced scripting language that prevents cross-chain interaction between chains that only have a simple (Bitcoin-like) scripting language. In this work, we introduce a novel payment channel protocol that breaks through all the above limitations. Our construction supports bidirectional, multiasset, and off-chain interaction across an arbitrary set of blockchains, where each update of the channel requires the parties to send only one message each. Our protocol is fully compatible with Bitcoin and can be deployed on chains with only minimal scripting capabilities, making it broadly applicable to real-world blockchain networks. Crucially, our design ensures atomic settlement across blockchains without relying on trusted intermediaries. We formally prove the security of our protocol together with a novel definition of the cross-chain payment channel that we introduce. Finally, we empirically validate our protocol, showing the minimal costs that our payment channel incurs in the setting where two parties make multiple exchanges of assets that reside on three different blockchains.

Discipline

Information Security

Research Areas

Information Systems and Management

Areas of Excellence

Digital transformation

Publication

Proceedings of the 29th International Conference, FC 2025, Miyakojima, Japan, April 14-18

First Page

1

Last Page

34

Publisher

Springer

City or Country

Cham

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