Andrés Ruiz-Chamorro, Alfonso Blanco, Natalia Denisenko and Verónica Fernández-Mármol
Photon 2022
Del 30 de agosto al 2 de septiembre de 2022, Nottingham, Reino Unido.
Quantum key distribution (QKD) is a secure communication method which uses quantum mechanics to implement cryptographic protocols. It enables two parties to produce a random secret key only known by them, which can then be used to encrypt and decrypt messages. The main property of QKD is that Alice and Bob (the two parties involved in the communication) are able to detect the presence of an eavesdropper which is trying to get the key. Continuous-variable quantum key distribution (CV-QKD) use bosonic modes of the electromagnetic field, which are described by an infinite-dimensional Hilbert space, to securely transmit a key over a noisy channel, using quantum uncertainty to detect the presence of an eavesdropper. Experimental CV-QKD systems present various difficulties in maintaining the security of the protocol due to the impairments of electronic and optical devices. Calibrating the systems taking these impairments into account has great advantages when predicting the behavior of an experimental CV-QKD system and allows for better secure key rates. In this work we develop a mathematical model and simulate an experimental CV-QKD system including multiple impairments, and we study how they affect the security and quality of the key.
