Paper 2008/342

Cryptanalysis of Li et al.'s Identity-Based Threshold Signcryption Scheme

S. Sharmila Deva Selvi, S. Sree Vivek, Neha Jain, and Pandu Rangan Chandrasekaran

Abstract

Signcryption is a cryptographic primitive that aims at providing confidentiality and authentication simultaneously. Recently in May 2008, a scheme for identity based threshold signcryption was proposed by Fagen Li and Yong Yu. They have proved the confidentiality of their scheme and have also claimed the unforgeability without providing satisfactory proof. In this paper, we show that in their signcryption scheme the secret key of the sender is exposed(total break) to the clerk during sincryption and hence insecure in the presence of malicious clerks. Further, we propose a corrected version of the scheme and formally prove its security under the existing security model for signcryption.

Note: Submitted to TSP '08

Metadata
Available format(s)
PDF PS
Category
Public-key cryptography
Publication info
Published elsewhere. Unknown where it was published
Keywords
CryptanalysisThreshold SigncryptionIdentity-BasedPairing
Contact author(s)
prangan55 @ gmail com
History
2008-08-11: received
Short URL
https://ia.cr/2008/342
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2008/342,
      author = {S.  Sharmila Deva Selvi and S.  Sree Vivek and Neha Jain and Pandu Rangan Chandrasekaran},
      title = {Cryptanalysis of Li et al.'s Identity-Based Threshold Signcryption Scheme},
      howpublished = {Cryptology ePrint Archive, Paper 2008/342},
      year = {2008},
      note = {\url{https://eprint.iacr.org/2008/342}},
      url = {https://eprint.iacr.org/2008/342}
}
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