**Author details**

*Quantum Cryptography in Advanced Networks*

Here, *I*(*A:B*) is the mutual information that Alice and Bob shared, and the maximum information shared for Alice and Eve is *S*(*A:E*). In this case, βgg is the reconciliation efficiency. In other hand, α is the classical channel efficiency that is based on the encoder capacity (related to the amount the erroneous bits that are detected and corrected). In this scenario, the dynamical atmospheric turbulence is represented by Rayleigh or Gamma-Gamma (GG) density probability functions,

*Block diagram of the simulation-experimental set-up of the QKD system proposed with dynamical encoder for* 

2

The proper understanding of the high-end hardware, protocols, techniques and schemes used in FSO-QKD systems allow to improve the performance parameters such as secret key rate, distance link, security level, among others. In particular, although there are wide suitable options for the subsystems required for FSO-QKD systems, it is necessary that the high-end subsystems are more accessible and compact in order to increase their uses in traditional optical networks.

Many thanks to CETYS University for the administrative and technical support

in the development of diverse projects related to the subject mentioned in this chapter. In addition, thanks to the Center of Innovation and Design (CEID) of Baja

California for the important discussion on improving quality of the chapter.

with the atmospheric turbulence, *αgg* and *βgg* are the effective numbers of large-scale and small-scale for GG function, respectively. Basically, Alice and Bob monitored the dynamical atmospheric turbulence calculating the error probabilities and

represents the Rytov variance related

, respectively, where <sup>σ</sup>*<sup>R</sup>*

*different atmospheric turbulence levels. Own figure and presented in [29].*

modifying LDPC encoder capacity used by them.

**34**

*Pe*(α,σ*<sup>R</sup>* 2

**Figure 4.**

)*c* and *Pe* (α,α*gg*, <sup>β</sup>*gg*)*<sup>c</sup>*

**5. Conclusions**

**Acknowledgements**

Josue Aaron Lopez-Leyva1 \*, Ariana Talamantes-Alvarez1 , Miguel A. Ponce-Camacho1 , Edith Garcia-Cardenas2 and Eduardo Alvarez-Guzman3

1 CETYS University, Baja California, Mexico

2 IBERO University, Baja California, Mexico

3 Autonomous University of Baja California, Baja California, Mexico

\*Address all correspondence to: josue.lopez@cetys.mx

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
