Free-Space Quantum Key Distribution

ABSTRACT: The secure transmission of digital information is of extreme importance for military and commercial applications. The need for protecting information from hostile eavesdroppers has motivated the search for novel security schemes. A Quantum Key Distribution (QKD) approach promises to provide a final solution to the problem by insuring unconditional security based upon the laws of quantum mechanics. Numerous experiments demonstrating QKD have been conducted in both fiber and free space configurations. While the performance of these systems in terms of key rates and distance is below that seen in classical transmission of information, the security promised by QKD makes it an enticing technology. The last frontier for QKD is satellite to ground applications, where the need is great to have unconditionally secure method for communications. To address this potential, SA Photonics proposes to develop the Sphinx QKD system for ground-LEO applications. The Sphinx system will provide robust, high performance key distribution with increased secure key rates by employing the following techniques: Innovative DSS single-photon APD architecture; Polarization-based BB84 protocol and Low loss optical and fiber-optic components BENEFIT: SA Photonics will use our DSS architecture and polarization-based BB84 protocol to develop a high secure key rate and robust ground-LEO QKD system. There are multiple benefits to the Air Force: Low development cost; Proven polarization-based BB84 protocol; Improved secure key rates; Rugged and reliable; Low unit cost