Parameter Analysis in Continuous-Variable Quantum Key Distribution with Arbitrary Modulation

Continuous-variable quantum key distribution (CV-QKD) represents a solution to distribute quantum-secure secret random keys, where weak coherent states can be encoded with Gaussian or discrete modulation. Using readily available and mature commercial off-the- shelf components, it is possible to achieve high secret key rates for practical short-reach optical communications. From the security proof perspective, it is possible to analyse the Gaussian modulation performance considering finite size effects. More recently, a security proof for arbitrary discrete modulation was proposed, but only in the asymptotic regime. In this work, finite size effects and confidence intervals are included in the models in order to get realistic bounds for relevant hardware implementation parameters for CV-QKD with arbitrary modulation. Furthermore, the optimum secret key rates were studied according to different Alice/Bob implementation parameters such as receiver clearance, channel loss, system excess noise, signal/LO lasers phase noise, signal modulation variance and quantum/calibration data lengths, with the Gaussian linear channel assumption.