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arXiv · 1606.01040

Soft McEliece: MDPC code-based McEliece cryptosystems with very compact keys through real-valued intentional errors

Marco Baldi·Paolo Santini·Franco Chiaraluce
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Abstract

We propose to use real-valued errors instead of classical bit flipping intentional errors in the McEliece cryptosystem based on moderate-density parity-check (MDPC) codes. This allows to exploit the error correcting capability of these codes to the utmost, by using soft-decision iterative decoding algorithms instead of hard-decision bit flipping decoders. However, soft reliability values resulting from the use of real-valued noise can also be exploited by attackers. We devise new attack procedures aimed at this, and compute the relevant work factors and security levels. We show that, for a fixed security level, these new systems achieve the shortest public key sizes ever reached, with a reduction up to 25% with respect to previous proposals.

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Marco Baldi, Paolo Santini, Franco Chiaraluce. 2016-06-03. Soft McEliece: MDPC code-based McEliece cryptosystems with very compact keys through real-valued intentional errors. https://doi.org/10.1109/isit.2016.7541408

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