(2026-02) Efficient, UC-secure and Publicly Auditable MPC from OLE & VOLE-in-the-head
2026-02-20
Secure Multiparty Computation (MPC) computes on private input data, but generally does not guarantee correctness of the output towards third parties. This property, also called public auditability, was first studied explicitly by Baum et al. (SCN 2014). Their work and its follow-ups generate a Non-Interactive Zero-Knowledge proof of correctness of the MPC outcome during the MPC protocol, ensuring validity of the output even if all parties are corrupted.
In this work, we revisit and improve the MPC with Public Auditability blueprint. While the original work uses a version of the SPDZ MPC protocol with expensive lattice-based preprocessing, our construction combines any generic OLE-based preprocessing with a publicly verifiable somewhat linearly homomorphic commitment scheme from VOLE-in-the-head in a non-trivial way. Our commitment scheme relies solely on random oracle calls instead of previously used linearly homomorphic commitments based on structured Public-Key assumptions.