Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tight bound on coherent states quantum key distribution with heterodyne
  detection   We propose a new upper bound for the eavesdropper's information in the direct
and reverse reconciliated coherent states quantum key distribution protocols
with heterodyne detection. This bound is derived by maximizing the leaked
information over the symplectic group of transformations that spans every
physical Gaussian attack on individual pulses. We exhibit four different
attacks that reach this bound, which shows that this bound is tight. Finally,
we compare the secret key rate obtained with this new bound to the homodyne
rate.

7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat