Ratel: MPC-extensions for Smart Contracts

Yunqi Li, Kyle Soska, Zhen Huang, Sylvain Bellemare, Mikerah Quintyne-Collins, Lun Wang, Xiaoyuan Liu, Dawn Song, Andrew Miller

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Enhancing privacy on smart contract-enabled blockchains has garnered much attention in recent research. Zero-knowledge proofs (ZKPs) is one of the most popular approaches, however, they fail to provide full expressiveness and fine-grained privacy. To illustrate this, we underscore an underexplored type of Miner Extractable Value (MEV), called Residual Bids Extractable Value (RBEV). Residual bids highlight the vulnerability where unfulfilled bids inadvertently reveal traders’ unmet demands and prospective trading strategies, thus exposing them to exploitation. ZKP-based approaches failed to address RBEV as they cannot provide post-execution privacy without some level of information disclosure. Other MEV mitigations like fair-ordering protocols also failed to address RBEV. We introduce Ratel, an innovative framework bridging a multi-party computation (MPC) prototyping framework (MP-SPDZ) and a smart contract language (Solidity), harmonizing the privacy with full expressiveness of MPC with Solidity’s on-chain programmability. This synergy empowers developers to effortlessly craft privacy-preserving decentralized applications (DApps). We demonstrate Ratel’s efficacy through two distinguished decentralized finance (DeFi) applications: a decentralized exchange and a collateral auction, effectively mitigating the potential RBEV issue. Furthermore, Ratel is equipped with a lightweight crash-reset mechanism, enabling the seamless recovery of transiently benign faulty nodes. To prevent the crash-reset mechanism abused by malicious entities and ward off DoS attacks, we incorporate a cost-utility analysis anchored in the Bayesian approach. Our performance evaluation of the applications developed under the Ratel framework underscores their competency in managing real-world peak-time workloads.

Original languageEnglish (US)
Title of host publicationACM AsiaCCS 2024 - Proceedings of the 19th ACM Asia Conference on Computer and Communications Security
PublisherAssociation for Computing Machinery
Pages336-352
Number of pages17
ISBN (Electronic)9798400704826
DOIs
StatePublished - Jul 1 2024
Event19th ACM Asia Conference on Computer and Communications Security, AsiaCCS 2024 - Singapore, Singapore
Duration: Jul 1 2024Jul 5 2024

Publication series

NameACM AsiaCCS 2024 - Proceedings of the 19th ACM Asia Conference on Computer and Communications Security

Conference

Conference19th ACM Asia Conference on Computer and Communications Security, AsiaCCS 2024
Country/TerritorySingapore
CitySingapore
Period7/1/247/5/24

Keywords

  • Secure Multiparty Computation (MPC)
  • blockchain
  • privacy

ASJC Scopus subject areas

  • Computational Theory and Mathematics
  • Computer Networks and Communications
  • Computer Science Applications

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