Preventing Timing Attacks Against RQC Using Constant Time Decoding of Gabidulin Codes

  • Slim Bettaieb
  • Loïc Bidoux
  • Philippe GaboritEmail author
  • Etienne Marcatel
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11505)


This paper studies the resistance of the code-based encryption scheme RQC to timing attacks. We describe two chosen ciphertext timing attacks that rely on a correlation between the weight of the error to be decoded and the running time of Gabidulin code’s decoding algorithm. These attacks are of theoretical interest as they outperform the best known algorithm to solve the rank syndrome decoding problem in term of complexity. Nevertheless, they are quite impracticable in real situations as they require a huge number of requests to a timing oracle. We also provide a constant-time algorithm for the decoding of Gabidulin codes that prevent these attacks without any performance cost for honest users.


RQC Gabidulin decoding Timing attack Rank metric 

Supplementary material


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Slim Bettaieb
    • 1
  • Loïc Bidoux
    • 1
  • Philippe Gaborit
    • 2
    Email author
  • Etienne Marcatel
    • 3
  1. 1.WorldlineSeclinFrance
  2. 2.University of Limoges, XLIM-DMILimogesFrance
  3. 3.AtosLes Clayes-sous-BoisFrance

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