Abstract: Continuous variables are attracting a lot of attention lately in the quantum cryptography community thanks to their good compatibility with telecom standards. In order to improve implementations, however, it appears fruitful to deviate from the original “all-Gaussian” protocols and to rely instead on encodings on discrete consellations of coherent states. While beneficial from an implementation viewpoint, this modification raises a number of difficulties when it comes to proving the security of the protocol. In this talk, I will review recent progress on security proofs of continuous-variable quantum key distribution with a discrete modulation, and try to outline possible approaches to solve the remaining challenges to bridge the gap between experimental implementations and security proofs.
