Paper 2026/170

gcVM: Publicly Auditable MPC via Garbled Circuits with Applications to Private EVM-Compatible Computation

Abstract

Blockchains have achieved substantial progress in scalability and fault tolerance, yet they remain fundamentally limited in confidentiality, hindering adoption by businesses, communities, and individuals who require privacy-preserving computations. Existing zero-knowledge (ZK) solutions provide partial privacy guarantees but struggle with performance and composability, especially for multi-party computations over shared private state. In this work, we introduce gcVM, a novel extension to the Ethereum Virtual Machine (EVM) that integrates garbled-circuit-based secure multi-party computation to enable general-purpose, privacy-preserving computation on-chain. gcVM allows transactional interactions between untrusted parties while balancing the transparency of public blockchains with strong confidentiality. Our implementation demonstrates up to 83 confidential transactions per second (cTPS) on standard cloud instances, with projected enhancements expected to scale throughput to approximately 500 cTPS—two to three orders of magnitude faster than comparable FHE-based solutions. gcVM is compatible with existing EVM tooling, provides public auditability, and requires no trusted hardware, offering a practical and efficient platform for privacy-centric blockchain applications across finance, governance, and decentralized services.