Paper 2016/512

Security Analysis of ePrint Report 2016/500 "Efficient Identity-Based Encryption and Public-Key Signature from Trapdoor Subgroups"

Lucjan Hanzlik and Kamil Kluczniak

Abstract

In this short report we analyse the security of three schemes proposed by J. H. Park et al. in "Efficient Identity-Based Encryption and Public-Key Signature from Trapdoor Subgroups". The schemes make use of trapdoor subgroups of $\ZZ_n^*$ and are secure under new assumptions called $q$-Trapdoor Subgroup Diffie-Hellman (TSDH) and $q$-Trapdoor Subgroup Exponent Inversion (TSEI). We show that given several secret keys in case of IBE or several signatures in case of PKS, one can easily extract the trapdoor and break security of the proposed schemes.

Note: This short report is an analysis of the recently published ePrint report 2016/500. Thus, this paper might not be without typos.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
attacktrapdoor subgroupcongruential equations
Contact author(s)
lucjan hanzlik @ pwr edu pl
History
2016-05-29: received
Short URL
https://ia.cr/2016/512
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2016/512,
      author = {Lucjan Hanzlik and Kamil Kluczniak},
      title = {Security Analysis of ePrint Report 2016/500 "Efficient Identity-Based Encryption and Public-Key Signature from Trapdoor Subgroups"},
      howpublished = {Cryptology ePrint Archive, Paper 2016/512},
      year = {2016},
      note = {\url{https://eprint.iacr.org/2016/512}},
      url = {https://eprint.iacr.org/2016/512}
}
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.