Composable Masking Schemes in the Presence of Physical Defaults & the Robust Probing Model

  • Sebastian Faust Technische Universität Darmstadt, Darmstadt
  • Vincent Grosso Radboud University Nijmegen, Digital Security Group
  • Santos Merino Del Pozo Université catholique de Louvain, ICTEAM/ELEN/Crypto Group, Belgium; DarkMatter LLC, Abu Dhabi
  • Clara Paglialonga Technische Universität Darmstadt, Darmstadt
  • François-Xavier Standaert Université catholique de Louvain, ICTEAM/ELEN/Crypto Group
Keywords: Side-channel analysis, security proofs, physical defaults, composability

Abstract

Composability and robustness against physical defaults (e.g., glitches) are two highly desirable properties for secure implementations of masking schemes. While tools exist to guarantee them separately, no current formalism enables their joint investigation. In this paper, we solve this issue by introducing a new model, the robust probing model, that is naturally suited to capture the combination of these properties. We first motivate this formalism by analyzing the excellent robustness and low randomness requirements of first-order threshold implementations, and highlighting the difficulty to extend them to higher orders. Next, and most importantly, we use our theory to design and prove the first higher-order secure, robust and composable multiplication gadgets. While admittedly inspired by existing approaches to masking (e.g., Ishai-Sahai-Wagner-like, threshold, domain-oriented), these gadgets exhibit subtle implementation differences with these state-of-the-art solutions (none of which being provably composable and robust). Hence, our results illustrate how sound theoretical models can guide practically-relevant implementations.

Published
2018-08-14
How to Cite
Faust, S., Grosso, V., Merino Del Pozo, S., Paglialonga, C., & Standaert, F.-X. (2018). Composable Masking Schemes in the Presence of Physical Defaults & the Robust Probing Model. IACR Transactions on Cryptographic Hardware and Embedded Systems, 2018(3), 89-120. https://doi.org/10.13154/tches.v2018.i3.89-120
Section
Articles