Publications

Profiling Side-Channel Attacks on Dilithium: A Small Bit-Fiddling Leak Breaks It All

AuthorUlitzsch, Vincent Quentin; Marzougui, Soundes; Tibouchi, Mehdi; Seifert, Jean Pierre
Date2024
TypeConference Paper
AbstractWe present an end-to-end (equivalent) key recovery attack on the Dilithium lattice-based signature scheme, one of the winners of the NIST postquantum cryptography competition. The attack is based on a small side-channel leakage we identified in a bit unpacking procedure inside Dilithium signature generation. We then combine machine-learning based profiling with various algorithmic techniques, including least squares regression and integer linear programming, in order to leverage this small leakage into essentially full key recovery: we manage to recover, from a moderate number of side-channel traces, enough information to sign arbitrary messages. We confirm the practicality of our technique using concrete experiments against the ARM Cortext-M4 implementation of Dilithium, and verify that our attack is robust to real-world conditions such as noisy power measurements. This attack appears difficult to protect against reliably without strong side-channel countermeasures such as masking of the entire signing algorithm, and underscores the necessity of implementing such countermeasures despite their known high cost.
Conference29th International Conference on Selected Areas in Cryptography, SAC 2022
Isbn9783031584107
ISSN03029743
Urlhttps://publica.fraunhofer.de/handle/publica/510473