Paper 2021/610

A Weighted Bit Flipping Decoder for QC-MDPC-based Cryptosystems

Alexander Nilsson, Irina E. Bocharova, Boris D. Kudryashov, and Thomas Johansson


A new ``Weighted Bit-flipping'' (WBF) iterative decoder is presented and analyzed with respect to its Decoding Failure Rate (DFR). We show that the DFR is indeed lower than that of the BGF decoder as suggested by the BIKE third round submission to the NIST PQC standardization process. The WBF decoder requires more iterations to complete than BGF, but by creating a hybrid decoder we show that a lower DFR compared to that of the BGF decoder can still be achieved while keeping the computational tradeoff to a minimum.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. IEEE ISIT 2021
Post Quantum CryptographyCoding TheoryQC-MDPC
Contact author(s)
alexander nilsson @ eit lth se
thomas johansson @ eit lth se
irinaboc @ ut ee
boriskud @ ut ee
2021-05-17: received
Short URL
Creative Commons Attribution


      author = {Alexander Nilsson and Irina E.  Bocharova and Boris D.  Kudryashov and Thomas  Johansson},
      title = {A Weighted Bit Flipping Decoder for QC-MDPC-based Cryptosystems},
      howpublished = {Cryptology ePrint Archive, Paper 2021/610},
      year = {2021},
      note = {\url{}},
      url = {}
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