Cryptology ePrint Archive: Report 2004/121

Fast and Proven Secure Blind Identity-Based Signcryption from Pairings

Tsz Hon Yuen and Victor K. Wei

Abstract: We present the first blind identity-based signcryption (BIBSC). We formulate its security model and define the security notions of blindness and parallel one-more unforgeability (p1m-uf). We present an efficient construction from pairings, then prove a security theorem that reduces its p1m-uf to Schnorr¡¦s ROS Problem in the random oracle model plus the generic group and pairing model. The latter model is an extension of the generic group model to add support for pairings, which we introduce in this paper. In the process, we also introduce a new security model for (non-blind) identity-based signcryption (IBSC) which is a strengthening of Boyen¡¦s. We construct the first IBSC scheme proven secure in the strenghened model which is also the fastest (resp. shortest) IBSC in this model or Boyen¡¦s model. The shortcomings of several existing IBSC schemes in the strenghened model are shown.

Category / Keywords: Blind Identity Based Signcryption

Date: received 22 May 2004, last revised 13 Jun 2004

Contact author: kwwei at ie cuhk edu hk

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Note: Extend the definition for generic group and pairing model

Version: 20040613:131434 (All versions of this report)

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