Continuous-variable quantum key distribution over multispan links employing phase-insensitive and phase-sensitive amplifiers
arXiv:2309.08041 · doi:10.1088/1367-2630/ad3774
Abstract
Transmission losses through optical fibers are one of the main obstacles preventing both long-distance quantum communications and continuous-variable quantum key distribution. Optical amplification provides a tool to obtain, at least partially, signal restoration. In this work, we address a key distribution protocol over a multispan link employing either phase-insensitive or phase-sensitive amplifiers, considering Gaussian modulation of coherent states followed by homodyne detection at the receiver's side. We perform the security analysis under both unconditional and composable security frameworks by assuming in the latter case only a single span of the whole communication link to be untrusted. We compare the resulting key generation rate for both kinds of amplified links with the no-amplifier protocol, identifying the enhancement introduced by optical amplification.
25 pages, 11 figures
References in corpus (9)
- Unconditional optimality of Gaussian attacks against continuous-variable QKD
- Quantum key distribution over 25 km with an all-fiber continuous-variable system
- Optimality of Gaussian Attacks in Continuous Variable Quantum Cryptography
- Improvement of continuous-variable quantum key distribution systems by using optical preamplifiers
- Improving the maximum transmission distance of continuous-variable quantum key distribution using a noiseless amplifier
- Composable security for continuous variable quantum key distribution: Trust levels and practical key rates in wired and wireless networks
- Telecom networking with a diamond quantum memory
- Classical capacity of phase-sensitive Gaussian quantum channels
- Ultimate capacity limit of a multi-span link with phase-insensitive amplification