Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cryptanalysis and improvement of the quantum private comparison protocol
  based on Bell entangled states   Recently, Liu et al. [Commun. Theor. Phys. 57, 583, 2012] proposed a quantum
private comparison protocol based on entanglement swapping of Bell states,
which aims to securely compare the equality of two participants' information
with the help of a semi-honest third party (TP). However, this study points out
there is a fatal loophole in this protocol, i.e., TP can obtain all of the two
participants secret inputs without being detected through making a specific
Bell-basis measurement. To fix the problem, a simple solution, which uses
one-time eavesdropper checking with decoy photons instead of twice eavesdropper
checking with Bell states, is demonstrated. Compared with the original
protocol, it also reduces the Bell states consumption and simplifies the steps
in the protocol.

5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph