Paper 2019/557 Original: eprint.iacr.org/2019/557 ↗

Extended Galbraith's Test on the Anonymity of IBEs from Higher Residuosity

Xiaopeng Zhao
Zhenfu Cao
Xiaolei Dong
Jun Shao
Abstract

At PKC 2019, Clear and McGoldrick presented the first identity-based encryption (IBE) scheme that supports homomorphic addition modulo a poly-sized prime $e$. Assuming that deciding solvability of a special system of multivariate polynomial equations is hard, they proved that their scheme for $e>2$ is anonymous. In this paper, we review the classical Galbraith's test on the anonymity of the first pairing-free IBE scheme due to Cocks. With the eye of the reciprocity law over $\mathbb{F}_\mathtt{q}[x]$, we can have a profound understanding of the test and naturally extend it to give a practical attack on the anonymity of the Clear-McGoldrick IBE scheme. Furthermore, we believe that our technique plays a crucial role in anonymizing IBE schemes from higher residuosity.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
History
2020-09-20: last updated
2019-05-25: published
Short URL
https://ia.cr/2019/557
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2019/557,
      author = {Xiaopeng Zhao and Zhenfu Cao and Xiaolei Dong and Jun Shao},
      title = {Extended Galbraith's Test on the Anonymity of IBEs from Higher Residuosity},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/557},
      year = {2019},
      url = {https://eprint.iacr.org/2019/557}
}
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