Publication
High-Speed Free-Space Quantum Key Distribution
| datacite.subject.fos | Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática | |
| dc.contributor.advisor | Cruzeiro, Emmanuel Zambrini | |
| dc.contributor.advisor | André, Sérgio de Brito | |
| dc.contributor.author | Ferreira,Ricardo Figueiredo | |
| dc.date.accessioned | 2025-11-18T15:40:57Z | |
| dc.date.available | 2025-11-18T15:40:57Z | |
| dc.date.issued | 2023-05-12 | |
| dc.description.abstract | The goal of cryptography is to encode data in such a way that no one can decode it unless they are the intended recipient. With the emergence of quantum computing, classical cryptography is not reliable enough to protect sensitive information. Nevertheless, there are alternatives. Quantum Key Distribution (QKD) is a method to secure communication based on the laws of quantum physics. Due to being impossible to measure the quantum state of a system without disturbing it, QKD provides a way to communicate between two parties while being, in theory, immune to eavesdropping. In this work, a free-space high-speed QKD setup is proposed, with the objective of implementing the polarization three-state one-decoy variant of the BB84 protocol. An assessment of the best type of laser diode to use for free-space QKD is made between several options. The system’s performance was assessed, incorporating a quantitative analysis of system losses and an estimation of the number of photons traversing the quantum channel. The system achieved a Quantum Bit Error Rate (QBER) of 1.58% for the Z basis and 1.46% for the X basis, for an average reception of two photons per pulse. Preliminary QBER measurements were also undertaken in the context of Quantum Keyless Private Communication protocols, focusing on the average number of photons per pulse. | por |
| dc.identifier.tid | 203574206 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/59861 | |
| dc.language.iso | por | por |
| dc.rights.uri | N/A | |
| dc.subject | Quantum Key Distribution | |
| dc.subject | Weak coherent pulses | |
| dc.subject | Quantum states measurements | |
| dc.subject | Secure optical communications. | |
| dc.title | High-Speed Free-Space Quantum Key Distribution | por |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| thesis.degree.grantor | Academia Militar | |
| thesis.degree.name | Mestrado em Engenharia Electrotécnica Militar |