Cryptology ePrint Archive: Report 2012/585

On Provably Secure Code-based Signature and Signcryption Scheme

Preetha Mathew K and Sachin Vasant and C. Pandu Rangan

Abstract: Signcryption is a cryptographic protocol that provides uthentication and confidentiality as a single primitive at a cost lower than the combined cost of sign and encryption. Code-based cryptography, a likely candidate for post-quantum cryptography, provides an exciting alternative to number-theoretic cryptography. Courtois, Finiasz and Sendrier proposed the only practical code-based signature(CFS signature) at Asiacrypt 2001. But that signature scheme currently lacks a formal proof of security due to the existence of the high rate distinguisher proposed by Fauge`re et al. In this paper, we make use of an alternate key-construct for the CFS signature, and thus prove its existential unforgeability under chosen message attacks (EUF-CMA). Also, we propose a code-based signcryption scheme and prove its security. To the best of our knowledge, this is the first code-based, provably secure signature and signcryption scheme in literature.

Category / Keywords: Signature, Signcryption, Code-based cryptography, CFS signature, Syndrome decoding.

Date: received 15 Oct 2012, last revised 29 Jul 2013

Contact author: preetha mathewkeerikkattil at gmail com

Available format(s): PDF | BibTeX Citation

Note: Some more justification given for hard problems used in the schemes

Version: 20130729:114828 (All versions of this report)

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