Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Monogamy of entanglement as a necessary and sufficient condition for
  safe QKD in any physical theory   We show that the monogamy of entanglement is a sufficient phenomenon in every
physical theory, if the quantum key distribution is to be safe on the grounds
of such theory. To do so we present the QKD protocol that is safe in any
physical theory under the assumption of the monogamous entanglement only. The
necessity of this condition is also discussed.

2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph