Paper 2024/1581 Original: eprint.iacr.org/2024/1581 ↗

$\mathsf{Protoss}$ Protocol for Tight Optimal Symmetric Security

Emanuele Di Giandomenico
Yong Li
Sven Schäge
Abstract

We present $\mathsf{Protoss}$, a new balanced PAKE protocol with optimal communication efficiency. Messages are only 160 bits long and the computational complexity is lower than all previous approaches. Our protocol is proven secure in the random oracle model and features a security proof in a strong security model with multiple parties and multiple sessions, while allowing for generous attack queries including multiple $\mathsf{Test}$-queries. Moreover, the proof is in the practically relevant single-bit model (that is harder to achieve than the multiple-bit model) and tightly reduces to the Strong Square Diffie-Hellman assumption (SSQRDH). This allows for very efficient, theoretically-sound instantiations and tight compositions with symmetric primitives.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2026-06-08: last updated
2024-10-07: published
Short URL
https://ia.cr/2024/1581
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2024/1581,
      author = {Emanuele Di Giandomenico and Yong Li and Sven Schäge},
      title = {$\mathsf{Protoss}$ Protocol for Tight Optimal Symmetric Security},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1581},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1581}
}
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