Paper 2025/359 Original: eprint.iacr.org/2025/359 ↗
A Note on Zero-Knowledge Simulator of the CROSS Identification Protocol
Abstract
We point out flaw in zero-knowledge of the CROSS identification protocol, $\textsf{CROSS-ID}$, which allows a distinguisher to distinguish real and simulated transcripts given access to the witness. Moreover, we show that the real and simulated transcripts are not statistically indistinguishable, and therefore the protocol can only satisfy weak computational (rather than strong, statistical or perfect) Honest Verifier Zero-knowledge. This issue is still present in version 2.0 updated on January 31, 2025, which resolves the security losses attained via the attacks of [BLP+25]
Metadata
- Available format(s)
PDF- Category
- Attacks and cryptanalysis
- Publication info
- Preprint.
- History
- 2025-02-25: last updated
- 2025-02-25: published
- Short URL
- https://ia.cr/2025/359
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2025/359,
author = {Shai Levin},
title = {A Note on Zero-Knowledge Simulator of the CROSS Identification Protocol},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/359},
year = {2025},
url = {https://eprint.iacr.org/2025/359}
}