Paper 2021/954

Scabbard: a suite of efficient learning with rounding key-encapsulation mechanisms

Jose Maria Bermudo Mera, Angshuman Karmakar, Suparna Kundu, and Ingrid Verbauwhede


In this paper, we introduce Scabbard, a suite of post-quantum key-encapsulation mechanisms. Our suite contains three different schemes Florete, Espada, and Sable based on the hardness of module- or ring-learning with rounding problem. In this work, we first show how the latest advancements on lattice-based cryptography can be utilized to create new better schemes and even improve the state-of-the-art on post-quantum cryptography. We put particular focus on designing schemes that can optimally exploit the parallelism offered by certain hardware platforms and are also suitable for resource constrained devices. We show that this can be achieved without compromising the security of the schemes or penalizing their performance on other platforms. To substantiate our claims, we provide optimized implementations of our three new schemes on a wide range of platforms including general-purpose Intel processors using both portable C and vectorized instructions, embedded platforms such as Cortex-M4 microcontrollers, and hardware platforms such as FPGAs. We show that on each platform, our schemes can outperform the state-of-the-art in speed, memory footprint, or area requirements.

Available format(s)
Publication info
Published by the IACR in TCHES 2021
Post-quantum cryptographyLearning with roundingKey-encapsulation mechanismLattice-based cryptographyEmbedded implementationsAVX2Cortex-M4FPGA
Contact author(s)
jbermudo @ esat kuleuven be
2021-07-22: received
Short URL
Creative Commons Attribution


      author = {Jose Maria Bermudo Mera and Angshuman Karmakar and Suparna Kundu and Ingrid Verbauwhede},
      title = {Scabbard: a suite of efficient learning with rounding key-encapsulation mechanisms},
      howpublished = {Cryptology ePrint Archive, Paper 2021/954},
      year = {2021},
      note = {\url{}},
      url = {}
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