Quantum key distribution (QKD) can generate secret cryptographic keys without relying on computational complexity for security. Such keys can be used in the only verifiably secret cipher, the Vernam, or one-time-pad cipher. However, this application requires cryptographic keys that are as long as the message to be encrypted, making one-time-pad encryption with previously demonstrated QKD systems impractical. We have applied telecommunication clock-synchronization techniques to significantly increase the capacity of QKD systems, resulting in error-corrected and privacy-amplified key rates above 1 Mbps. This performance is roughly two orders of magnitude greater than previous demonstrations, and enabled the one-time-pad encryption of streaming video signals. I will give an introduction to QKD and present a detailed overview of our technical approach that highlights paths to increased performance.
Joshua Bienfang received his PhD from the University of New Mexico in 2001 for his work in laser frequency stabilization and continuous-wave Raman lasers. In 2002 at the Air Force Research Labs in Albuquerque, NM, he developed a 20-Watt continuous-wave source at 589 nm for use in adaptive optics. From 2003 to 2005 he was a National Research Council post-doctoral researcher at NIST, and is now a staff scientist.