X-Transfer: Enabling and Optimizing Cross-PCN Transactions

Lukas Aumayr; Zeta Avarikioti; Iosif Salem; Stefan Schmid; Michelle Yeo

Paper 2025/272

X-Transfer: Enabling and Optimizing Cross-PCN Transactions

Lukas Aumayr

, University of Edinburgh, Common Prefix

Zeta Avarikioti

, TU Wien, Common Prefix

Iosif Salem

, TU Berlin, ZeroPoint Technologies

Stefan Schmid

, TU Berlin

Michelle Yeo

, National University of Singapore

Abstract

Blockchain interoperability solutions allow users to hold and transfer assets among different chains, and in so doing reap the benefits of each chain. To fully reap the benefits of multi-chain financial operations, it is paramount to support interoperability and cross-chain transactions also on Layer-2 networks, in particular payment channel networks (PCNs). Nevertheless, existing works on Layer-2 interoperability solutions still involve on-chain events, which limits their scalability and throughput. In this work, we present X-Transfer, the first secure, scalable, and fully off-chain protocol that allows payments across different PCNs. We formalize and prove the security of X-Transfer against rational adversaries with a game theoretic analysis. In order to boost efficiency and scalability, X-Transfer also performs transaction aggregation to increase channel liquidity and transaction throughput while simultaneously minimizing payment routing fees. Our empirical evaluation of X-Transfer shows that X-Transfer achieves at least twice as much throughput compared to the baseline of no transaction aggregation, confirming X-Transfer's efficiency.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Financial Cryptography and Data Security 2025
Keywords: payment channel networks layer 2 interoperability optimization transaction aggregation cryptocurrencies
Contact author(s): laumayr @ ed ac uk
georgia avarikioti @ tuwien ac at
iosif salem @ zptcorp com
stefan schmid @ tu-berlin de
mxyeo @ nus edu sg
History: 2025-02-18: approved; 2025-02-18: received; See all versions
Short URL: https://ia.cr/2025/272
License: CC BY

BibTeX

@misc{cryptoeprint:2025/272,
      author = {Lukas Aumayr and Zeta Avarikioti and Iosif Salem and Stefan Schmid and Michelle Yeo},
      title = {X-Transfer: Enabling and Optimizing Cross-{PCN} Transactions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/272},
      year = {2025},
      url = {https://eprint.iacr.org/2025/272}
}