Physical security of code-based cryptosystems

by Brice Colombier (Laboratoire Hubert Curien), Pierre-Louis Cayrel (Laboratoire Hubert Curien)

Monday Jul 7, 2025, 2:00 PM → 4:00 PM Europe/Paris

L020 (Campus Manufacture)

Although code-based cryptosystems have existed for several decades, they have only been adopted for specific use cases due to performance and memory constraints, despite their long-standing track record of resisting cryptanalysis. However, they have recently received a lot of research attention thanks to the NIST post-quantum cryptography standardisation process, which began in 2016. One aspect of this process involves evaluating the resistance of these cryptosystems to physical attacks, where an attacker has physical access to the device running the programme.
In this presentation, we consider the Classic McEliece cryptosystem. After recalling its three main algorithms, we present two attacks that aim to recover the short-term secret and one that targets the long-term secret. Finally, we discuss possible countermeasures to prevent these attacks and share some observations that may be of interest to mathematically inclined researchers.