Séminaire

Date : 21 octobre 2025 14:00 - Salle :C101 Quantum Key Distribution, cellular automata based large S-Box and almost key homomorphic block cipher for long term secret storage Thomas PREVOST - Université Côte d’Azur

In this seminar, I will present different approaches to achieve long-term confidential storage. I will first present Quantum Key Distribution, which ensures Information Theoretic Secure confidentiality, i.e., guaranteed regardless of the evolution of the adversary's computing power. We will then discuss the limitations of such an approach. Subsequently, we will discuss the design of large S-Boxes based on cellular automata, in order to achieve more secure block encryption. I will then present the S-Box that we designed based on such a method, which has security properties comparable to, or even better than, those of AES. Finally, I will present an almost key homomorphic block encryption algorithm, which allows key rotation with possible updating of its security level. This system thus makes it possible to scale the security level with the attacker's computing power.