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Disclaimer Notice & Privacy Policy / Security Notice Send comments or suggestions to webmaster@antd.nist.gov The National Institute of Standards and Technology is an Agency of the U.S. Commerce Department's Technology Administration Created, maintained and owned by: ANTD's webmaster Last updated: August, 2007 Date Created: June, 2007 |
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ITL quantum communication research team have developed a new
configuration for quantum key distribution (QKD) systems, in which the minimum number
of single photon detectors needed is halved. The new configuration greatly simplifies
the QKD structure and therefore reduced its cost.
ITL's Advanced
Networking Division and Security Division are colaborating
to investigate the problems and complexity of integrating Quantum Key Distribution (QKD)
into existing network security protocols. Exisiting security protocols rely on public
key exchange methods to distribute secure keys. When quantum computers are developed such
key exchange mechanisms will be broken. Transitioning to future technologies,
such as QKD, must be done well before such threats become reality.
A
QKD system, built in ITL, produced quantum secure keys at a rate of more
than 2 million bits per second (bps) over 1 kilometer (km) of optical
fiber. This is a step toward using conventional optical fiber to distribute
quantum crypto keys in local-area networks (LANs).
ITL
researchers have developed a high speed active three-node QKD network,
in which the QKD path can be routed by optical switches. Using this network,
a QKD secured video surveillance system has been successfully demonstrated.
NIST
researchers developed a quantum key distribution system with photons being
transmitted at 1310 nm, where fiber loss is small, and after wavelength
conversion, being detected at 710 nm, where single photons can be detected
with good performance. 
Scientists
from ITL and the Physics Labarotory tested a QKD by transmitting photons
over free space between two NIST buildings that are 730 meters apart.
High-speed
electronics boards for controlling the NIST QKD system were designed for
both the key sender (Alice) and receiver (Bob). An FPGA on each board
allows for complex parallel logic that is reprogramable providing a path
for revisions and enhancements. 
Fiber
loss is small around 1310 nm and 1550 nm. Single photons can be detected
with good performance between 600 and 900 nm. The up-conversion, technology,
developed by ITL, helps to solve this dilemma. 
NIST
computer scientists have developed a high-speed approach to error correction
adapted from telecommunications techniques. This makes it possible to
correct bit errors rapidly without time-consuming discussions between
sender and receiver and without wasting key bits by revealing it to a
potential eavesdropper. 