We propose a costless platform for fair exchange based on smart contracts to favor economic inclusion. Our smart contract is minimal, as most of communication is done offchain. The smart contract costs are covered by incentivized sponsors. Our protocol is a knowledge-coin exchange: it allows to exchange a digital item, characterized by an automatically verifiable description, against a payment in cryptocurrency. The exchange is fair in the sense that either both parties receive what they expect (the exchange completes) or both parties lose nothing (the exchange is canceled). We ensure a costless transaction in cancelation cases, and a transaction with pre-determined fee if it completes. We also ensure privacy of the transaction. Our protocol offers an improvement compared to OptiSwap: we can work with any description function. The complexity is never higher and sometimes significantly smaller. Namely, the worst case complexity is logarithmic instead of being linear. Furthermore, we introduce sponsoring as an enabler for economic inclusion.
Note: Presented at the Workshop on Cryptographic Tools for Blockchains (CTB) 2026 - affiliated with EUROCRYPT 2026.
BibTeX
@misc{cryptoeprint:2026/904,
author = {Serge Vaudenay},
title = {Sponsored Fair Exchange (Extended Abstract)},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/904},
year = {2026},
url = {https://eprint.iacr.org/2026/904}
}
此内容由惯性聚合(RSS阅读器)自动聚合整理，仅供阅读参考。 原文来自 — 版权归原作者所有。