QKD Technologies for Space-Based Laser Communications

Quantum key distribution (QKD) technology offers the promise of provably secure encryption by utilizing the fundamental quantum mechanical nature of photons. However, free-space communication systems present a number of challenges for practical implementation of QKD. The QKD loss tolerance must be improved, exchange rates increased, and the implementations must evolve toward more robust and autonomous operation. In Phase I of this SBIR, approaches for achieving each of these goals were identified, and through a combination of analysis and simulations, each of the approaches was evaluated for effectiveness and practicality based on currently available technology. Detailed block diagrams were developed for the critical subsystems that incorporate the techniques identified to provide the most benefit in performance. The Phase II program will support product development of a number of novel QKD subsystem modules that incorporate these advances. The enhanced performance of the modules will be demonstrated through a series of laboratory and test-bed demonstrations. The result of this program will be subsystems with demonstrated performance advantages that can be integrated into both government and commercial cryptographic systems.