Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Cryptanalysis of Quantum Secure Direct Communication Protocol with
  Mutual Authentication Based on Single Photons and Bell States
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph