Long-term performance of the SwissQuantum quantum key distribution network in a field environment

Abstract

In this paper, we report on the performance of the SwissQuantum quantum key distribution (QKD) network. The network was installed in the Geneva metropolitan area and run for more than one and a half years, from the end of March 2009 to the beginning of January 2011. The main goal of this experiment was to test the reliability of the quantum layer over a long period of time in a production environment. A key management layer has been developed to manage the key between the three nodes of the network. This QKD-secure network was used by end-users through an application layer.PACS numbers: 03.67.Dd, 03.67.Hk, ‡ D Stucki and M Legré contributed equivalently to the writing of this paper.

Maintenance-free operation of WDM quantum key distribution system through a field fiber over 30 days

“…The total number of secure bits distributed over the 22 km installed fiber for a 30-day uninterrupted duration of continuous operation amounts to 595.6 Gbits. This is an order of magnitude larger than those in the previous works, such as 70.3 Gbits over the 3.7 km installed fiber for 327 days (SQ3 link from 3 Sep 2009 to 26 July 2010) by Stucki et al [16], and 63.3 Gbits by Dynes et al over the 45-km installed fiber for 60 hours [17]. To capture the quality of long-term QKD operation, one may introduce a new figure of merit, namely the channel-loss normalized secure key, defined by an amount of distributed secure key in total divided by a channel loss.…”

Distant entanglement enhanced in PT -symmetric optomechanics

“…However, there are still some limitations to fully handle certain quantum optomechanical applications and so numerous efforts are ongoing. Indeed, quantum entanglement is often limited by various factors such as the stability conditions that place constraints on the magnitude of the effective optomechanical couplings [31]- [33] and the amplification effect in the unstable regime [34]. In particular, thermal noise of the mechanical modes can strongly impair the generation of such nonclassical states.…”

Countermeasure against blinding attacks on low-noise detectors with a background-noise-cancellation scheme

“…In the commercial arena, in particular, great progresses have been recently achieved in the area of high-speed QKD and long distance quantum network systems [14][15][16][17][18][19][20][21][22][23][24][25]. Many studies on QKD security have been also conducted uninterruptedly since 1984, because providing security is essential for the commercialization of such systems.…”