Security and sovereignty of information are granted today by complex mathematical algorithm-based cryptography. The rise of quantum computing will challenge our state-of-the art, mathematical based encryption technologies. By fighting quantum challenges with quantum technologies, we develop and deliver quantum key distribution (QKD) systems based on entangle photon sources. This allows the implementation of cyber security solutions based on physical laws. Quantum Optics Jena covers the whole process chain from entangled photon sources, quantum state analyzers to quantum key-generation and -management systems. We offer solutions for fiber-based networks as well as payloads and sub-systems for future QKD-satellite networks and constellations. We e ...