Paper 2023/1381

Sometimes You Can’t Distribute Random-Oracle-Based Proofs

Jack Doerner, Brown University
Yashvanth Kondi, Silence Laboratories (Deel)
Leah Namisa Rosenbloom, Brown University
Abstract

We investigate the conditions under which straight-line extractable NIZKs in the random oracle model (i.e. without a CRS) permit multiparty realizations that are black-box in the same random oracle. We show that even in the semi-honest setting, any MPC protocol to compute such a NIZK cannot make black-box use of the random oracle or a hash function instantiating it if security against all-but-one corruptions is desired, unless the number of queries made by the verifier to the oracle grows linearly with the number of parties. This presents a fundamental barrier to constructing efficient protocols to securely distribute the computation of NIZKs (and signatures) based on MPC-in-the-head, PCPs/IOPs, and sigma protocols compiled with transformations due to Fischlin, Pass, or Unruh. When the adversary is restricted to corrupt only a constant fraction of parties, we give a positive result by means of a tailored construction, which demonstrates that our impossibility does not extend to weaker corruption models in general.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Published by the IACR in CRYPTO 2024
Keywords
Threshold CryptographyMultiparty ComputationStraight-line ExtractionNIZKZero-knowledgeSignatures
Contact author(s)
j @ ckdoerner net
yash @ ykondi net
leah_rosenbloom @ brown edu
History
2024-06-01: revised
2023-09-14: received
See all versions
Short URL
https://ia.cr/2023/1381
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/1381,
      author = {Jack Doerner and Yashvanth Kondi and Leah Namisa Rosenbloom},
      title = {Sometimes You Can’t Distribute Random-Oracle-Based Proofs},
      howpublished = {Cryptology ePrint Archive, Paper 2023/1381},
      year = {2023},
      note = {\url{https://eprint.iacr.org/2023/1381}},
      url = {https://eprint.iacr.org/2023/1381}
}
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