### IvyCross: A Privacy-Preserving and Concurrency Control Framework for Blockchain Interoperability

Ming Li, Jian Weng, Yi Li, Yongdong Wu, Jiasi Weng, Dingcheng Li, Guowen Xu, and Robert Deng

##### Abstract

Interoperability is a fundamental challenge for long-envisioned blockchain applications. A mainstream approach is to use Trusted Execution Environment (TEEs) to support interoperable off-chain execution. However, this incurs multiple TEEs configured with non-trivial storage capabilities running on fragile concurrent processing environments, rendering current strategies based on TEEs far from practical. The purpose of this paper is to fill this gap and design a practical interoperability mechanism with simplified TEEs as the underlying architecture. Specifically, we present IvyCross, a TEE-based framework that achieves low-cost, privacy-preserving, and race-free blockchain interoperability. Specifically, IvyCross allows running arbitrary smart contracts across heterogenous blockchains atop only two distributed TEE-powered hosts. We design an incentive scheme based on smart contracts to stimulate the honest behavior of two hosts, bypassing the requirement of the number of TEEs and large memory storage. We examine the conditions to guarantee the uniqueness of the Nash Equilibrium via Sequential Game Theory. Furthermore, a novel extended optimistic concurrency control protocol is designed to guarantee the correctness of concurrent execution of off-chain contracts. We formally prove the security of IvyCross in the Universal Composability framework and implement a proof-of-concept prototype atop Bitcoin, Ethereum, and FISCO BOCS. The experiments indicate that (i) IvyCross is able to support privacy-preserving and multiple-round smart contracts for cross-chain communication; (ii) IvyCross successfully decreases the off-chain costs on storage and communication of a TEE without using complex cryptographic primitives; and (iii) the total on-chain transaction fees in cross-chain communication are relatively low, within ranges of 0.2 USD ~ 1 USD.

Available format(s)
Category
Applications
Publication info
Preprint. MINOR revision.
Keywords
Blockchain interoperabilityprivacy-preservingsmart contractsTEE.
Contact author(s)
limjnu @ gmail com
History
2022-03-04: last of 3 revisions
See all versions
Short URL
https://ia.cr/2021/1244

CC BY

BibTeX

@misc{cryptoeprint:2021/1244,
author = {Ming Li and Jian Weng and Yi Li and Yongdong Wu and Jiasi Weng and Dingcheng Li and Guowen Xu and Robert Deng},
title = {IvyCross: A Privacy-Preserving and Concurrency Control Framework for Blockchain Interoperability},
howpublished = {Cryptology ePrint Archive, Paper 2021/1244},
year = {2021},
note = {\url{https://eprint.iacr.org/2021/1244}},
url = {https://eprint.iacr.org/2021/1244}
}

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