Masked Computation the Floor Function and its Application to the FALCON Signature

Pierre-Augustin Berthet; Justine Paillet; Cédric Tavernier

Paper 2024/709

Masked Computation the Floor Function and its Application to the FALCON Signature

Pierre-Augustin Berthet

, Institut Mines-Télécom, Hensoldt SAS France

Justine Paillet

, Université Jean Monnet, Hensoldt SAS France

Cédric Tavernier

, Hensoldt SAS France

Abstract

FALCON is candidate for standardization of the new Post Quantum Cryptography (PQC) primitives by the National Institute of Standards and Technology (NIST). However, it remains a challenge to define efficient countermeasures against side-channel attacks (SCA) for this algorithm. FALCON is a lattice-based signature that relies on rational numbers which is unusual in the cryptography field. While recent work proposed a solution to mask the addition and the multiplication, some roadblocks remain, most noticeably how to protect the floor function. We propose in this work to complete the existing first trials of hardening FALCON against SCA. We perform the mathematical proofs of our methods as well as formal security proof in the probing model using the Non-Interference concepts.

Note: Revision 1 : Changed the paper structure for clarity and added the performances of a complete masked FALCON

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Floor Function Floating-Point Arithmetic Post-Quantum Cryptography FALCON Side-Channel Analysis Masking
Contact author(s): berthet @ telecom-paris fr
justine paillet @ univ-st-etienne fr
cedric tavernier @ hensoldt net
History: 2024-09-12: revised; 2024-05-08: received; See all versions
Short URL: https://ia.cr/2024/709
License: CC BY

BibTeX

@misc{cryptoeprint:2024/709,
      author = {Pierre-Augustin Berthet and Justine Paillet and Cédric Tavernier},
      title = {Masked Computation the Floor Function and its Application to the {FALCON} Signature},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/709},
      year = {2024},
      url = {https://eprint.iacr.org/2024/709}
}