Paper 2025/2185

Fully Adaptive Threshold IBE and Signatures in the Standard Model

Jiayun Yan, East China Normal University
Yu Li, University of Wollongong
Jie Chen, Wuhan University
Haifeng Qian, East China Normal University
Xiaofeng Chen, Xidian University
Debiao He, Wuhan University
Abstract

We present fully adaptive secure threshold IBE and threshold signatures, which rely on the $k$-Linear assumption in the standard model over asymmetric pairing groups. In particular, our threshold signature scheme achieves a non-interactive signing process and an adaptively secure guarantee as strong as Das-Ren (CRYPTO'24), while their proof relies on the random oracle model. We achieve our results by following steps: First, we design two threshold IBE schemes against adaptive corruptions in the composite-order and prime-order groups by adopting the dual system groups encoding. Second, we provide a generic transform from threshold IBE to threshold signatures, following Naor's paradigm, which reduces the fully adaptive corruption security of threshold signatures to threshold IBE. Third, we present two threshold signatures instantiations in composite-order and prime-order groups.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
Threshold IBEThreshold signaturesAdaptive corruptionsDual system groups
Contact author(s)
yanjiayun01 @ 163 com
im @ liyu im
s080001 @ e ntu edu sg
hfqian @ cs ecnu edu cn
xfchen @ xidian edu cn
hedebiao @ whu edu cn
History
2025-12-04: approved
2025-12-02: received
See all versions
Short URL
https://ia.cr/2025/2185
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/2185,
      author = {Jiayun Yan and Yu Li and Jie Chen and Haifeng Qian and Xiaofeng Chen and Debiao He},
      title = {Fully Adaptive Threshold {IBE} and Signatures in the Standard Model},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/2185},
      year = {2025},
      url = {https://eprint.iacr.org/2025/2185}
}
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