Applied Algebra Group at the University of Zürich


Construction and Decoding of MDPC Codes for McEliece Crptosystems

Dr. Hannes Bartz's talk
Date: 10.10.18   Time: 16.00 - 17.00   Room: Y27H12

Moderate-Density Parity-Check (MDPC) codes are a promising class of codes to design post-quantum secure McEliece cryptosystems with compact keys. In this talk, a new construction and improved decoding approaches for MDPC codes are presented. In particular, ensembles of quasi-cyclic MDPC codes based on protographs are introduced and analyzed. The proposed ensembles significantly improve the error correction capability of the regular MDPC code ensembles that are currently considered for MDPC-McEliece cryptosystem without increasing the public key size.
Additionally, a new message-passing decoding approach for MDPC codes that has an improved error-correction performance compared to existing hard-decision decoding schemes is presented. The decoding scheme can reduce the effectiveness of the recent reaction-based key-recovery attack on the MDPC-McEliece cryptosystem by Guo, Johansson and Stankovski (GJS) for an appropriate choice of the algorithm’s parameters.