Paper 2023/1280 Original: eprint.iacr.org/2023/1280 ↗
Quantum Security of TNT
Abstract
Many classical secure structures are broken by quantum attacks. Evaluating the quantum security of a structure and providing a tight security bound is a challenging research area. As a tweakable block cipher structure based on block ciphers, $\mathsf{TNT}$ was proven to have $O(2^{3n/4})$ CPA and $O(2^{n/2})$ CCA security in the classical setting. We prove that $\mathsf{TNT}$ is a quantum-secure tweakable block cipher with a bound of $O(2^{n/6})$. In addition, we show the tight quantum PRF security bound of $O(2^{n/3})$ when $\mathsf{TNT}$ is based on random functions, which is better than $O(2^{n/4})$ given by Bhaumik et al. and solves their open problem. Our proof uses the recording standard oracle with errors technique of Hosoyamada and Iwata based on Zhandry’s compressed oracle technique.
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2023-08-31: last updated
- 2023-08-25: published
- Short URL
- https://ia.cr/2023/1280
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2023/1280,
author = {Shuping Mao and Zhiyu Zhang and Lei Hu and Luying Li and Peng Wang},
title = {Quantum Security of TNT},
howpublished = {Cryptology {ePrint} Archive, Paper 2023/1280},
year = {2023},
url = {https://eprint.iacr.org/2023/1280}
}