Continuous-variable quantum key distribution in uniform fast-fading channels

Abstract

Article:Papanastasiou, Panagiotis, Weedbrook, Christian and Pirandola, Stefano orcid.org/0000-0001- 6165-5615 (2018) We investigate the performance of several continuous-variable quantum key distribution protocols in the presence of fading channels. These are lossy channels whose transmissivity changes according to a probability distribution. This is typical in communication scenarios where remote parties are connected by free-space links subject to atmospheric turbulence. In this work, we assume the worst-case scenario where an eavesdropper has full control of a fast fading process, so that she chooses the instantaneous transmissivity of a channel, while the remote parties can only detect the mean statistical process. In our study, we consider coherent-state protocols run in various configurations, including the one-way switching protocol in reverse reconciliation, the measurementdevice-independent protocol in the symmetric configuration and a three-party measurement-deviceindependent network. We show that, regardless of the advantage given to the eavesdropper (full control of fading), these protocols can still achieve high rates.

Fading channel estimation for free-space continuous-variable secure quantum communication

“…. This case has been recently studied as a model for fastfading channels in [40]. In the asymptotic case this results in a very large effective excess noise (even up to e » 20% eff ), therefore it is no wonder that without clustering we obtain the lowest key rate here.…”

“…If the transmittance is completely random, that is, it is uniformly distributed between 0 and 1 (blue circles), then its fluctuation will be very high (Var ( √ T i ) = 0.055). This case has been recently studied as a model for fast-fading channels in [25]. In the asymptotic case this results in a very large effective excess noise (even up to ε ef f ≈ 20%), therefore it is no wonder that without clustering we obtain the lowest key rate here.…”

Performance evaluation and security analysis of ground‐to‐satellite FSO system with CV‐QKD protocol

“…Variations in the performance of a QKD system due to the non-idealistic of different devices have been studied and modelled in [44]. The effects of fastfading channels have been analysed in [45]. In [46], new communication protocols are developed using high-dimensional quantum states so that more than one classical bit can be transferred by each photon, which will enhance the secure key rate in QKD systems.…”

Satellite-Based Continuous-Variable Quantum Communications: State-of-the-Art and a Predictive Outlook

“…Note that in[185], a fast-fading channel has been considered where the users are only able to estimate the probability distribution of the channel's transmission coefficient but not its instantaneous values, while the eavesdropper has full control of the fast-fading channel, so that she chooses the instantaneous transmission coefficient of the channel.…”