Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental quantum key distribution with simulated ground-to-satellite
  photon losses and processing limitations   Quantum key distribution (QKD) has the potential to improve communications
security by offering cryptographic keys whose security relies on the
fundamental properties of quantum physics. The use of a trusted quantum
receiver on an orbiting satellite is the most practical near-term solution to
the challenge of achieving long-distance (global-scale) QKD, currently limited
to a few hundred kilometers on the ground. This scenario presents unique
challenges, such as high photon losses and restricted classical data
transmission and processing power due to the limitations of a typical satellite
platform. Here we demonstrate the feasibility of such a system by implementing
a QKD protocol, with optical transmission and full post-processing, in the
high-loss regime using minimized computing hardware at the receiver. Employing
weak coherent pulses with decoy states, we demonstrate the production of secure
key bits at up to 56.5 dB of photon loss. We further illustrate the feasibility
of a satellite uplink by generating secure key while experimentally emulating
the varying channel losses predicted for realistic low-Earth-orbit satellite
passes at 600 km altitude. With a 76 MHz source and including finite-size
analysis, we extract 3374 bits of secure key from the best pass. We also
illustrate the potential benefit of combining multiple passes together: while
one suboptimal "upper-quartile" pass produces no finite-sized key with our
source, the combination of three such passes allows us to extract 165 bits of
secure key. Alternatively, we find that by increasing the signal rate to 300
MHz it would be possible to extract 21570 bits of secure finite-sized key in
just a single upper-quartile pass.

34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol