Paper 2008/373

Analysis and Improvement of Authenticatable Ring Signcryption Scheme

Fagen Li, Masaaki Shirase, and Tsuyoshi Takagi

Abstract

Ring signcryption is an anonymous signcryption which allows a user to anonymously signcrypt a message on behalf of a set of users including himself. In an ordinary ring signcryption scheme, even if a user of the ring generates a signcryption, he also cannot prove that the signcryption was produced by himself. In 2008, Zhang, Yang, Zhu, and Zhang solve the problem by introducing an identity-based authenticatable ring signcryption scheme (denoted as the ZYZZ scheme). In the ZYZZ scheme, the actual signcrypter can prove that the ciphertext is generated by himself, and the others cannot authenticate it. However, in this paper, we show that the ZYZZ scheme is not secure against chosen plaintext attacks. Furthermore, we propose an improved scheme that remedies the weakness of the ZYZZ scheme. The improved scheme has shorter ciphertext size than the ZYZZ scheme. We then prove that the improved scheme satisfies confidentiality, unforgeability, anonymity and authenticatability.

Metadata
Available format(s)
PDF PS
Category
Public-key cryptography
Publication info
Published elsewhere. Journal of Shanghai Jiaotong University (Science)
Keywords
Identity-based cryptographybilinear pairingsring signcryptionring signature
Contact author(s)
fagenli @ uestc edu cn
History
2009-04-08: last of 3 revisions
2008-09-01: received
See all versions
Short URL
https://ia.cr/2008/373
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2008/373,
      author = {Fagen Li and Masaaki Shirase and Tsuyoshi Takagi},
      title = {Analysis and Improvement of Authenticatable Ring Signcryption Scheme},
      howpublished = {Cryptology ePrint Archive, Paper 2008/373},
      year = {2008},
      note = {\url{https://eprint.iacr.org/2008/373}},
      url = {https://eprint.iacr.org/2008/373}
}
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