Résumé : Quantum information offers fundamentally new ways to achieve cryptographic tasks, sometimes beyond the capabilities of classical cryptography. In these two lectures, I will first introduce the important concepts in Quantum Information, and we will try to understand together how quantum communication enables new possibilities for cryptographic protocols. We will then explore quantum key distribution (QKD), the most well-known quantum cryptography protocol, understanding how it works and its security guarantees. I will also go beyond QKD to briefly discuss other cryptographic primitives where quantum cryptography has fundamental advantages and limitations, such as commitment or coin flipping. Finally, I will discuss emerging research directions in quantum communication that push the boundaries of secure information processing.

Keywords : quantum cryptography; quantum information; quantum protocols