In our days, computing devices slowly reach their computational limits, since the circuit units cannot be reduced significantly with modern technology. However, there are growing number of telecommunications and IT problems which need a solution. A solution to these problems could be the quantum computing. It is based on the laws of quantum mechanics and works with mainly atomic-scale elements and offers new and unusual opportunities for the classical world.
Quantum Key Distribution (QKD) is one of the most discussed topics of quantum computing. QKD is a method, which is demonstrably safe and assists to create private keys between two communicating parties on a public channel. These keys have great role in the secure communications, because a classical symmetrical encryption system could be built with their assist. I studied the BB84 protocol, which is a very important QKD protocol.
Quantum communications provides secure and reliable key distribution protocols, therefore the quantum based solutions can be used effectively in different satellite communications. We can distinguish Earth-satellite, satellite-Earth and satellite-satellite quantum commination. The last one is interesting since there are no longer prevail the disturbing effects of the atmosphere.
In my work, I have examined the operation and effectiveness of the S13 protocol in Earth-satellite channel. The S13 protocol was published by Eduin H. Serna in 2013. I carried out developments on a Java-based simulation framework to perform the analysis of the protocol. In my research, I considered the characteristics of free-space quantum based communication (e.g., weather conditions, environmental influences), and calculated with different orbit heights. I have analyzed not only the S13 protocol, but I compared it with the operations of the BB84.