Amirhossein Ghazisaeidi | LIP6 - Équipe QI

Shaped Constellation Continuous Variable Quantum Key Distribution: Concepts, Methods and Experimental Validation

Thu, 01 Aug 2024 00:00:00 +0000

Quantum key distribution (QKD) enables the establishment of secret keys between users connected via a channel vulnerable to eavesdropping, with information-theoretic security, that is, independently of the power of a malevolent party (Scarani et al., 2009). QKD systems based on the encoding of the key information on continuous variables (CV), such as the values of the quadrature components of coherent states (Weedbrook et al., 2012), (Diamanti and Leverrier, 2015), present the major advantage that they only require standard telecommunication technology. However, the most general security proofs for CV-QKD required until now the use of Gaussian modulation by the transmitter, complicating practical implementations (Jouguet et al., 2013), (Zhang et al., 2020), (Jain et al., 2022). Here, we experimentally implement a protocol that allows for arbitrary, Gaussian-like, discrete modulations, whose security is based on a theoretical proof that applies generally to such situations (Denys et al., 2021). These modulation formats are compatible with the use of powerful tools of coherent optical telecommunication, allowing our system to reach an estimated performance of tens of megabit per second secret key rates over 25 km.

Experimental Demonstration of Discrete Modulation Formats for Continuous Variable Quantum Key Distribution

Sun, 24 Jul 2022 00:00:00 +0000

High-Rate Continuous Variable Quantum Key Distribution Based on Probabilistically Shaped 64 and 256-QAM

Mon, 13 Sep 2021 00:00:00 +0000

We designed a CV-QKD system with off-the-shelf components and established the feasibility of distributing 67.6 and 66.8 Mb/s secret key rates on average over a 9.5 km SMF link, using respectively probabilistically shaped 64 and 256 QAM, and relying on a novel analytical security proof.

Demonstration of Probabilistic Constellation Shaping for Continuous Variable Quantum Key Distribution

Sun, 06 Jun 2021 00:00:00 +0000

We demonstrate, for the first time to our knowledge, continuous-variable quantum key distribution using probabilistically-shaped 1024-QAM and true local oscillator, achieving 38.3Mb/s secret key rate over 9.5km, averaged over the transmission time of 100 blocks.