Paper 2020/1084 Original: eprint.iacr.org/2020/1084 ↗
Fully Collision-Resistant Chameleon-Hashes from Simpler and Post-Quantum Assumptions
Abstract
Chameleon-hashes are collision-resistant hash-functions parametrized by a public key. If the corresponding secret key is known, arbitrary collisions for the hash can be found. Recently, Derler et al. (PKC '20) introduced the notion of fully collision-resistant chameleon-hashes. Full collision-resistance requires the intractability of finding collisions, even with full-adaptive access to a collision-finding oracle. Their construction combines simulation-sound extractable (SSE) NIZKs with perfectly correct IND-CPA secure public-key encryption (PKE) schemes. We show that, instead of perfectly correct PKE, non-interactive commitment schemes are sufficient. For the first time, this gives rise to efficient instantiations from plausible post-quantum assumptions and thus candidates of chameleon-hashes with strong collision-resistance guarantees and long-term security guarantees. On the more theoretical side, our results relax the requirement to not being dependent on public-key encryption.
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2020-09-10: last updated
- 2020-09-10: published
- Short URL
- https://ia.cr/2020/1084
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2020/1084,
author = {David Derler and Stephan Krenn and Kai Samelin and Daniel Slamanig},
title = {Fully Collision-Resistant Chameleon-Hashes from Simpler and Post-Quantum Assumptions},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/1084},
year = {2020},
url = {https://eprint.iacr.org/2020/1084}
}