Featured Research

from universities, journals, and other organizations

New Technologies Enhance Quantum Cryptography

Date:
February 2, 2006
Source:
Los Alamos National Laboratory
Summary:
A team of Los Alamos National Laboratory scientists, in collaboration with researchers from the National Institute of Standards and Technology in Boulder, Colo., and Albion College, in Albion, Mich., have achieved quantum key distribution (QKD) at telecommunications industry wavelengths in a 50-kilometer (31 mile) optical fiber. The work could accelerate the development of QKD for secure communications in optical fibers at distances beyond current technological limits.

A team of Los Alamos National Laboratory scientists, in collaboration with researchers from the National Institute of Standards and Technology in Boulder, Colo., and Albion College, in Albion, Mich., have achieved quantum key distribution (QKD) at telecommunications industry wavelengths in a 50-kilometer (31 mile) optical fiber. The work could accelerate the development of QKD for secure communications in optical fibers at distances beyond current technological limits.

In research published recently in Applied Physics Letters, the team describes the use of new superconducting transition-edge sensors (TES) to distribute cryptographic key material at wavelengths of 1,550 nanometers through 50 kilometers of optical fiber. TES could provide increases in range and performance over current QKD photon detection schemes. Unlike the single-photon sensitive avalanche photodiodes (APD) that are typically used in optical fiber QKD systems, TESs detect photons by measuring minute temperature increases in a superconducting material caused by the absorption of individual photons.

"The enhancements we've made," said Los Alamos quantum physicist Danna Rosenberg, "center around a new method of detecting single photons, which can be one of the most challenging aspects of QKD. The TESs provide significantly higher detection efficiencies and lower dark count rates than those of typical APDs. The high efficiency and low probability of dark counts, coupled with the relatively short recovery time of TESs, should permit higher secret key transmission rates at longer distances than APD-based systems."

In addition to employing TESs, the team experimented with bright optical pulse and electrical signal synchronization schemes. One method of synchronization involved sending a bright 1,310 nanometer pulse just before sending a 1,550 nanometer pulse. Using a bright pulse reduced transmission errors that might occur due to changes in the length or optical properties of the fiber link. An electrical synchronization scheme used a rubidium atomic clock to synchronize information senders and receivers.

When used with electrical synchronization schemes, the TESs have the potential to increase distances that optical fibers could be used for QKD. Using the current system, the maximum transmission distances for data with bright pulse and electrical synchronization are 83 kilometers (51.57 miles) and 138 kilometers (85.75 miles), respectively. More sophisticated methods of filtering photons than the experimenters employed, might someday allow users to send quantum keys securely over distances in excess of 270 kilometers (167.77 miles), compared to the current record of 122 kilometers (75.8 miles).

In addition to Rosenberg, who was formerly with the National Institute of Standards and Technology, the TES QKD team includes Sae Woo Nam, Adriana Lita and Aaron Miller at the National Institute of Standards and Technology in Boulder, and Philip Hiskett, Glen Peterson, Richard Hughes, and, the team's leader, Jane Nordholt at Los Alamos.

###

Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear deterrent, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to defense, energy, environment, infrastructure, health and national security concerns.


Story Source:

The above story is based on materials provided by Los Alamos National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Los Alamos National Laboratory. "New Technologies Enhance Quantum Cryptography." ScienceDaily. ScienceDaily, 2 February 2006. <www.sciencedaily.com/releases/2006/02/060202181623.htm>.
Los Alamos National Laboratory. (2006, February 2). New Technologies Enhance Quantum Cryptography. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2006/02/060202181623.htm
Los Alamos National Laboratory. "New Technologies Enhance Quantum Cryptography." ScienceDaily. www.sciencedaily.com/releases/2006/02/060202181623.htm (accessed October 2, 2014).

Share This



More Matter & Energy News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins