Equivalent Keys: Side-Channel Countermeasure for Post-Quantum Multivariate Quadratic Signatures
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Rok
2022
Publikováno
Electronics. 2022, 11(21), ISSN 2079-9292.
Typ
Článek
Pracoviště
Anotace
Algorithms based on the hardness of solving multivariate quadratic equations present promising candidates for post-quantum digital signatures. Contemporary threats to implementations of cryptographic algorithms, especially in embedded systems, include side-channel analysis, where attacks such as differential power analysis allow for the extraction of secret keys from the device’s power consumption or its electromagnetic emission. To prevent these attacks, various countermeasures must be implemented. In this paper, we propose a novel side-channel countermeasure for multivariate quadratic digital signatures through the concept of equivalent private keys. We propose a random equivalent key to be generated prior to every signing, thus randomizing the computation and mitigating side-channel attacks. We demonstrate our approach on the Rainbow digital signature, but since an unbalanced oil and vinegar is its special case, our work is applicable to other multivariate quadratic signature schemes as well. We analyze the proposed countermeasure regarding its properties such as the number of different equivalent keys or the amount of required fresh randomness, and we propose an efficient way to implement the countermeasure. We evaluate its performance regarding side-channel leakage and time/memory requirements. Using test vector leakage assessment, we were not able to detect any statistically significant leakage from our protected implementation.
Side-channel attack on Rainbow post-quantum signature
Autoři
Rok
2021
Publikováno
Proceedings of the 2021 Design, Automation & Test in Europe (DATE). New Jersey: IEEE, 2021. p. 565-568. ISSN 1558-1101. ISBN 978-3-9819263-5-4.
Typ
Stať ve sborníku
Anotace
Rainbow, a layered multivariate quadratic digital signature, is a candidate for standardization in a competition-like process organized by NIST. In this paper, we present a CPA side-channel attack on the submitted 32-bit reference implementation. We evaluate the attack on an STM32F3 ARM microcontroller,successfully revealing the full private key. Furthermore, we propose a simple masking scheme with minimum overhead.