Laszlo Bacsardi1, Mate Galambos1, Sandor Imre1, Andras Kis2
1Department of Telecommunications, Budapest University of Technology and Economics
2Institute of Informatics and Economics, University of West Hungary
In the last few years, quantum theory based on quantum mechanical principles has appeared in satellite communication offering answers for some of nowadays’ technical questions. Since all classical cryptographic schemes could be broken by quantum computers in the future, the relevance of quantum cryptography will be unquestionable in future’s secure communication. With the help of quantum cryptography, forces of nature can be used to implement perfectly secure cryptosystems.
For modeling the quantum based satellite-satellite communication, we created a mathematical model which is based on the behavior of single-photon sources and detectors and on the losses originated from beam spreading and pointing error. Based on this model, we have developed a simulator software to study the quantum communication over Earth-space and space-space links, e.g., between two satellites. We analyzed the performance of three quantum key distribution (QKD) protocols—BB84, B92, S09—on different Earth-space and space-space links including Earth-LEO (Low Earth Orbit), LEO-Earth, LEO-LEO, Earth-GEO (Geostationary Earth Orbit), GEO-Earth and GEO-GEO communication channels. In practical usage of laser communication, we cover the examination of key distribution procedure by BB84, B92 and S09 protocols.