High-repetition rate quantum key distribution
Joshua C. Bienfang, Alessandro Restelli, Daniel J. Rogers, Alan Mink, Barry Hershman, Anastase Nakassis, Xiao Hong Tang, Lina Ma, Hai Peng Xu, David H. Su, Charles W. Clark, Carl J. Williams · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
The desire for quantum-generated cryptographic key for broadband encryption services has motivated the development of high-transmission-rate single-photon quantum key distribution (QKD) systems. The maximum operational transmission rate of a QKD system is ultimately limited by the timing resolution of the single-photon detectors and recent advances have enabled the demonstration of QKD systems operating at transmission rates well in to the GHz regime. We have demonstrated quantum generated one-time-pad encryption of a streaming video signal with high transmission rate QKD systems in both free-space and fiber. We present an overview of our high-speed QKD architecture that allows continuous operation of the QKD link, including error correction and privacy amplification, and increases the key-production rate by maximizing the transmission rate and minimizing the temporal gating on the single-photon channel. We also address count-rate concerns that arise at transmission rates that are orders of magnitude higher than the maximum count rate of the single-photon detectors.