Laboratoire IMATH

Titre :
Quantum Key Distribution and cryptography for long term secret storage

Résumé :
In a context where data leaks are increasingly frequent, cryptography appears today as the best way to guarantee the confidentiality of our data. However, most of the cryptographic primitives used today could prove vulnerable in a more or less distant future. We think for example of the quantum computer which should overcome certain primitives of asymmetric encryption. Or even of the constant evolution of the computing power of our machines, which raises fears of brute force attacks in the future. In this seminar, we will see how Quantum Key Distribution (QKD), a new method of transmitting cryptographic keys based on quantum physics, allows to guarantee unconditional confidentiality regardless of the evolution of the attacker’s cryptanalysis power. We will then present the MULTISS protocol, a protocol for long-term confidential storage across several remote QKD networks. We will also present a post-quantum symmetric encryption primitive, allowing the security level of the ciphertext to be updated on the fly as the attacker’s computing power evolves.