# Shared Quantum Key Distribution Based on Asymmetric Double Quantum Teleportation
## 6 Some Final Considerations about Benchmarking, Decoherence Effects, and Fidelity
### Quantum Processing in QKD Developments and Post-Quantum Cryptography  
The protocol proposed has implemented quantum processing to a great extent compared with the most traditional procedures. Because quantum cryptography promises unconditional security in data communication because it is currently pretended to be deployed for military and commercial applications, it should be secure. Despite QKD is being widely adopted, it still faces several important challenges regarding the rates for secret key settlement, communication distance and decoherence, deployment sizes, the effective cost in terms of quantum resources, maintenance, and security [64]. As it was stated through the development, quantum coherence is preferable mandatory to reach all the basic features provided by Quantum mechanics.  
Quantum computers are believed to solve (at least via problem translation) any exponential problem in principle solvable by a classical computer but not in a finite time. Then, due to classical cryptography protocols are commonly breakable in an exponential time, they are susceptible to failure under such scenarios. Then, with the advent of quantum computers, the necessity to develop secure QKD protocols under their possible attacks is mandatory. Post-quantum cryptography (sometimes also referred as quantum-safe cryp  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Process** & \multicolumn{3}{c}{**1**} & \multicolumn{3}{c}{**2**} & \multicolumn{3}{c}{**3**} & **Total** \\ \cline{2-7} \& **Qubits** & **X** & **Z** & **Hadamard** & \(C^{\ast}NOT_{b}\) & \(SWAP_{ab}\) & \(C^{\ast}U_{ij}\) & **Toffoli** & \\ \hline DT & 4 & 2 & 1 & 0 & 0 & 0 & 2 & 9 \\ PP & 4 & 1 & 1 & 1 & 1 & 10 & 1 & 19 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Depth and number of each type of gate involved through the different steps of the whole QKD protocol (DT and PP).  
tography) deals with cryptographic algorithms thought to be secure against cryptanalytic attacks performed by an ideal quantum computer in terms of coherence, prompt quantum resources, and speed-up [32].  
While in conventional symmetric cryptography algorithms, the security in communication is solely related to the secrecy of the encryption key, other QKD protocols currently studied, exploit an asymmetry in their implementation, thus stating the state-of-the-art in their practical implementations [64]. In the post-quantum cryptography terrain, despite currently experimental quantum computers still lacking processing power to break any contemporary cryptographic algorithm, people working in the frontier of theoretical cryptography are preparing impressive protocols to prepare for a time when quantum computers become a real threat. It requires implementing mathematics, physics, and technology to a great extent.  
Cryptography systems are commonly grouped in several cryptographic classes [17]. Despite linear, our procedure could be adapted to be asymmetrically non-linear in (24); together, authentication introduced by \(\omega_{i}\) parameters could be specialized to introduce a Courtois, Finiasz and Sendrier Signature scheme [65], thus being able to fall in the Multivariate-quadratic-equations and the Code-based schemes. It suggests a fusion between the classical cryptography schemes with trends based on Quantum mechanics features.