PROCEEDINGS ARTICLE | August 29, 2006
Proc. SPIE. 6305, Quantum Communications and Quantum Imaging IV
KEYWORDS: Switching, Polarization, Video, Photons, Video surveillance, Optical communications, Optical switching, Quantum key distribution, Network architectures, Quantum communications
We previously demonstrated a high speed, point to point, quantum key distribution (QKD) system with polarization
coding over a fiber link, in which the resulting cryptographic keys were used for one-time pad encryption of real time
video signals. In this work, we extend the technology to a three-node active QKD network - one Alice and two Bobs. A
QKD network allows multiple users to generate and share secure quantum keys. In comparison with a passive QKD
network, nodes in an active network can actively select a destination as a communication partner and therefore, its
sifted-key rate can remain at a speed almost as high as that in the point-to-point QKD. We demonstrate our three-node
QKD network in the context of a QKD secured real-time video surveillance system. In principle, the technologies for the
three-node network are extendable to multi-node networks easily. In this paper, we report our experiments, including
the techniques for timing alignment and polarization recovery during switching, and discuss the network architecture and
its expandability to multi-node networks.
