Paper 2025/772

Publicly Auditable Garbled Circuit

San Ling, Nanyang Technological University
Chan Nam Ngo, Privacy + Scaling Explorations
Khai Hanh Tang, Nanyang Technological University
Huaxiong Wang, Nanyang Technological University
Abstract

Generic Secure Multiparty Computation (Generic MPC) recently received much attraction in the blockchain realm as it allows mutually distrustful parties to jointly compute a global function using their private inputs while keeping them private; and more so; the expression of the function can be done in a programmable manner (hence `generic'); as opposed to the first rising star cryptographic technique Zero-Knowledge Proof (ZKP) which only allows computation on private input of a single party (via the `commit-and-prove' approach). While ZKP, by nature, allows public verifiability, Generic MPC is not so: Generic MPC mostly focuses on Malicious Security in which the computing result is verifiable only among the computing parties. Yet, in the blockchain realm, public verifiability is important, as the consensus protocol is not just among the computing parties but also external servers. A few works were done to bridge this gap (albeit not in the blockchain realm), i.e., Public Auditable MPC. Public Audtitability is a stronger property than Public Verifiability: the first one certifies the computation done in the MPC, while the latter certifies only the relation between the outputs and the inputs. However, they are non-constant round protocols and only for Secret-Sharing-based MPC, i.e., round complexity scales linearly with the circuit multiplicative depth, while round latency is an important cost metric in the blockchain domain. We address this problem by providing a Public Auditable Garbled Circuit protocol that is maliciously secure, publicly auditable, and constant-round. Our protocol is efficient, with only minimal overhead in terms of round, communication, and public transcript size.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
Keywords
Garbled circuitVOLEVOLEitHpublic verifierMPC
Contact author(s)
lingsan @ ntu edu sg
namncc @ pse dev
khaihanh tang @ ntu edu sg
hxwang @ ntu edu sg
History
2025-04-30: approved
2025-04-30: received
See all versions
Short URL
https://ia.cr/2025/772
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/772,
      author = {San Ling and Chan Nam Ngo and Khai Hanh Tang and Huaxiong Wang},
      title = {Publicly Auditable Garbled Circuit},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/772},
      year = {2025},
      url = {https://eprint.iacr.org/2025/772}
}
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