Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Eavesdropping on the "Ping-Pong" Quantum Communication Protocol Freely
  in a Noise Channel   We introduce an attack scheme for eavesdropping the ping-pong quantum
communication protocol proposed by Bostr$\ddot{o}$m and Felbinger [Phys. Rev.
Lett. \textbf{89}, 187902 (2002)] freely in a noise channel. The vicious
eavesdropper, Eve, intercepts and measures the travel photon transmitted
between the sender and the receiver. Then she replaces the quantum signal with
a multi-photon signal in a same state, and measures the photons return with the
measuring basis with which Eve prepares the fake signal except for one photon.
This attack increase neither the quantum channel losses nor the error rate in
the sampling instances for eavesdropping check. It works for eavesdropping the
secret message transmitted with the ping-pong protocol. Finally, we propose a
way for improving the security of the ping-pong protocol.

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The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas