Paper 2012/585

On Provably Secure Code-based Signature and Signcryption Scheme

Preetha Mathew K, Sachin Vasant, and C. Pandu Rangan


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.

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

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Publication info
Preprint. MINOR revision.
SignatureSigncryptionCode-based cryptographyCFS signatureSyndrome decoding.
Contact author(s)
preetha mathewkeerikkattil @ gmail com
2013-07-29: last of 2 revisions
2012-10-16: received
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      author = {Preetha Mathew K and Sachin Vasant and C.   Pandu Rangan},
      title = {On Provably Secure Code-based Signature and Signcryption Scheme},
      howpublished = {Cryptology ePrint Archive, Paper 2012/585},
      year = {2012},
      note = {\url{}},
      url = {}
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