Évaluation de la Sécurité Contre les Attaques par Canaux Auxiliaires : Perspectives à partir d'une Vision Théorique de l'Information
Yi Liu · theses.fr (ABES) · 2023
In today's world, the widespread use of cryptographic devices highlights the need for their secure operation. Unintended leakages, like time, power, and electromagnetic emissions, can allow attackers to deduce secret keys via side-channel attacks (SCAs). Evaluating the security of cryptographic devices against SCAs is important for both the industrial and academic sectors, and information-theoretic metrics turn out to be effective tools. “Masking” stands out as a key countermeasure, with ongoing discussions on its optimization and the security of its implementations. In light of this context, the central aims of this thesis are to quantify side-channel leakage, appraise the security of cryptographic devices against SCAs (both unprotected and masked), and to explore methodologies for formulating more potent masking codes. For masking code construction, we establish linear programming bounds for the kissing number of q-ary linear codes, guided by recent findings on optimized code-based masking performance related to the dual code's kissing number. In addition, we demonstrate the connection between code-based masking efficacy and the whole weight enumeration of the dual of the masking code. The lexicographical order based on weight distribution prefixes is proposed for selecting ideal masking codes. Regarding side-channel leakage evaluation, we introduce a novel information metric, called conditional Sibson's alpha-information. This metric has an explicit expression and possesses several beneficial properties. Utilizing this metric, we delve into the sidechannel leakage of unprotected devices. Additionally, we use Fano's mutual information to evaluate the sidechannel leakage of code-based masked implementations under probing model. Lastly, when considering the security assessment of masked implementations, we utilize the alphainformation measure to appraise the security of both arithmetic and Boolean masking implementations. We derive universal bounds on the probability of success of any type of side-channel attack. These also provide lower bounds on the minimum number of queries required to achieve a given success rate.