Quantum key distribution in real life
The quantum key distribution (QKD) technique establishes secret keys shared between two communicating parties. Theoretically, unconditional security provided by QKD is guaranteed by the fundamental laws of quantum physics. in the real life, it is still possible to obtain unconditionally secure QK...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IDOSI Publication
2012
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/28060/ http://irep.iium.edu.my/28060/ http://irep.iium.edu.my/28060/1/5.pdf |
| Summary: | The quantum key distribution (QKD) technique establishes secret keys shared between two
communicating parties. Theoretically, unconditional security provided by QKD is guaranteed by the
fundamental laws of quantum physics. in the real life, it is still possible to obtain unconditionally secure
QKD, even with (phase randomized) attenuated laser pulses, as theoretically demonstrated by
Gottesman-Lo-L¨utkenhaus-Preskill (GLLP). However, one must pay a steep price by placing severe limits on
the distance and the key generation rate. These problems were solved using the decoy state method introduced
by Hwang. In this paper, we have proposed a method to estimate parameters of the decoy state method based
on two decoy state protocol for both BB84 and SARG04. The vacuum and weak decoy state protocol has been
introduced as a special case of two decoy states protocol. This method has given different lower bound of
the fraction of single-photon counts (y1), the fraction of two-photon counts (y2), the upper bound QBER of
single-photon pulses (e1), the upper bound QBER of two-photon pulses (e2) and the lower bound of key
generation rate for both BB84 and SARG04. The fiber based QKD systems also have been simulated using the
proposed method for BB84 and SARG04. The numerical simulation has shown that the fiber based QKD
systems using the proposed method for BB84 are able to achieve both a higher secret key rate and greater
secure distance than that of SARG04.
Key words: Quantum cryptography % Quantum key distribution % Decoy state protocol and optical
communications |
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