Paper 2025/179

Probing Secure Composability Without Fresh Randomness: Theory and Application to Ascon

Vahid Jahandideh, Radboud University Nijmegen
Bart Mennink, Radboud University Nijmegen
Lejla Batina, Radboud University Nijmegen
Abstract

Side-channel attacks (SCAs) pose a significant threat to the implementations of lightweight ciphers, particularly in resource-constrained environments where masking—the primary countermeasure—is constrained by tight resource limitations. This makes it crucial to reduce the resource and randomness requirements of masking schemes. In this work, we investigate an approach to minimize the randomness complexity of masking algorithms. Specifically, we explore the theoretical foundations of higher-order masking schemes that eliminate the need for online (fresh) randomness by relying solely on offline randomness present in the initial input shares. We demonstrate that round-based ciphers with linear diffusion layers can support such deterministic composition, where the diffusion layer acts as a refresh subcircuit. This ensures that, up to a threshold number, probes placed across rounds remain independent. Based on this observation, we propose composition theorems for probing-secure masking. On the practical side, we instantiate our framework using known deterministic first- and second-order masked S-boxes and provide software implementations of Ascon’s protected permutation.

Metadata
Available format(s)
PDF
Category
Implementation
Publication info
A major revision of an IACR publication in TCHES 2025
Keywords
Side-ChannelMaskingRandomness ComplexityAscon
Contact author(s)
v jahandideh @ cs ru nl
b mennink @ cs ru nl
lejla @ cs ru nl
History
2025-07-14: last of 2 revisions
2025-02-06: received
See all versions
Short URL
https://ia.cr/2025/179
License
Creative Commons Attribution-ShareAlike
CC BY-SA

BibTeX

@misc{cryptoeprint:2025/179,
      author = {Vahid Jahandideh and Bart Mennink and Lejla Batina},
      title = {Probing Secure Composability Without Fresh Randomness: Theory and Application to Ascon},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/179},
      year = {2025},
      url = {https://eprint.iacr.org/2025/179}
}
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.