Paper 2022/1063 Original: eprint.iacr.org/2022/1063 ↗
Rapidash: Atomic Swaps Secure under User-Miner Collusion
Abstract
Cross-chain trading is fundamental to blockchains and Decentralized Finance (DeFi). A way to achieve such trading in a truly decentralized manner, i.e., without trusted third parties, is by using atomic swaps. However, recent works revealed that Hashed Time-Lock Contract, a key building block of the existing atomic swaps, is entirely insecure in the presence of user-miner collusion. Specifically, a user can bribe the miners of the blockchain to help it cheat. In this work, we give the first and rigorous formal treatment of fair trading on blockchains, where users and miners may enter arbitrary binding contracts on the side. We propose Rapidash, a new atomic swap protocol, and prove its incentive-compatibility in the presence of user-miner collusion. Specifically, we show that Rapidash satisfies a coalition-resistant Nash equilibrium absent external incentives. We give instantiations of Rapidash that are compatible with Bitcoin and Ethereum, and incur only minimal overheads in terms of costs for the users.
Metadata
- Available format(s)
PDF- Category
- Cryptographic protocols
- Publication info
- Preprint.
- History
- 2025-06-26: last updated
- 2022-08-16: published
- Short URL
- https://ia.cr/2022/1063
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2022/1063,
author = {Hao Chung and Elisaweta Masserova and Elaine Shi and Sri AravindaKrishnan Thyagarajan},
title = {Rapidash: Atomic Swaps Secure under User-Miner Collusion},
howpublished = {Cryptology {ePrint} Archive, Paper 2022/1063},
year = {2022},
url = {https://eprint.iacr.org/2022/1063}
}