Paper 2026/1795 Original: eprint.iacr.org/2026/1795 ↗

On Removing Interaction from Quantum Proofs

Nicholas Spooner
Max Tromanhauser
Abstract

An important open question in quantum cryptography is the construction of publicly-verifiable NIZKs for QMA. Classically, one can construct NIZKs for NP in the random oracle model (and sometimes in the standard model) by compiling an honest-verifier ZK (HVZK) $\Sigma$-protocol for NP using the Fiat–Shamir transformation. Broadbent and Grilo introduced a quantum analog of a $\Sigma$-protocol (which they call a $\Xi$-protocol) in which the prover's first message is quantum, and show that HVZK $\Xi$-protocols exist for QMA. However, it is not clear how to compile such protocols into NIZKs in the (Q)ROM, because the Fiat–Shamir transformation seems to be incompatible with quantum messages. In this work we give formal evidence that this is indeed the case: we show that if generic "Fiat–Shamir-like" compilers for quantum protocols exist in the QROM (with small completeness and soundness error) then QMA = BQP.

Metadata
Available format(s)
PDF
Category
Foundations
Publication info
Preprint.
History
2026-10-01: last updated
2026-08-25: published
Short URL
https://ia.cr/2026/1795
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2026/1795,
      author = {Nicholas Spooner and Max Tromanhauser},
      title = {On Removing Interaction from Quantum Proofs},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/1795},
      year = {2026},
      url = {https://eprint.iacr.org/2026/1795}
}
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