Quantum Information Networks

Goals

Provides an infrastructure for quantum key distribution (QKD) metrology, research, testing, calibration and technological development.
Research the development of quantum network based on integrating QKD protocols with the internet.

Technical Approach

Develop and instrument a distributed QuIN (Quantum Information Network) testbed for experimenting with quantum key distribution (QKD) hardware and software technology.
Prototype quantum key distribution protocols and evaluate their performance in QuIN testbed.
Characterize the performance limitations of an optical quantum communication link.
Research techniques to improve the performance of quantum key distribution protocols.

Accomplishments

This is a joint project between several NIST laboratories: Electronics and Electrical Engineering, Information Technology, and Physics. This page covers the tasks completed by this Division. For more details concerning the NIST Quantum Information Program, please see http://qubit.nist.gov

Phase I Accomplishment (Architectural Design):
Completed the initial architectural design of the system, including hardware and software components.

Architecture of NIST QuIN testbed

Phase II Accomplishments (Component Design and Implementation):
A four-channel 1G Ethernet WDM system, and the optical interfaces to telescopes were completed. These classical channels are to be used for sending timing and framing information.

Click image to enlarge WDM for 1.25GHz classical links	Click image to enlarge Optical interface for quantum links

The high-speed electronics for controlling the full system was designed and the circuit boards were fabricated. An FPGA on each board allows for complex parallel logic that is reprogramable providing a path for revisions and enhancements.

Click image to enlarge	Click image to enlarge
PCI interface high-speed electronic boards for Alice (left) and Bob (right)

Completed the device drivers for the PCI boards which provide access to the hardware. Completed the basic upper layer software for system control and management of secrets (obtaining, maintaining, and using quantum keys), and interactions with applications that need encryption.

Phase III Accomplishments (System Integration and Performance Measurements): We integrated the NIST custom high-speed electronics, which handles a large potion of the BB84 QKD protocol, to the Quantum devices and optics on the lower layers and to the communications software algorithms, Sifting and Error Reconciliation (Cascade) on the higher layers. Bring this highly experimental system to life required significant tuning and enhancements of all the layers of our testbed. An early indication of our success is the preliminary 1 Mb/s Sifted Key rate we were able to achieve from our initial integrated Testbed trails.
Click image to enlarge High Speed Electronics Communicating using the QKD Protocol Stack	Click image to enlarge Optical Network – Quantum Channels and Classical channels

The QKD Protocol Stack

Phase IV Accomplishments (Enhancements & Fiber Development):
During 2005-2006 we have attained significant performance results with the development of a polarization encoded fiber-based QKD system. Initial performance for a B92 protocol implementation was measured in excess of 1 Mb/s Sifted Key rate, followed by a number enhancements performance was doubled to 2 Mb/s Sifted Key rate and 1 Mb/s Privacy Amplified secure key. After upgrading the system to conduct the BB84 protocol, performance was measured in excess of 4 Mb/s Sifted Key rate with an error rate of 3.6% over 1km of fiber. The technical details are described in the publication "Experimental Study of High Speed Polarization-Coding Quantum Key Distribution with Sifted-Key Rates Over Mbit/s," Optics Express, Vol. 14, No. 6, p.2062 (2006).

Furthermore, as part of its open testbed function super conducting single photon detectors, developed in NIST’s EEEL were installed in place of the original silicon detectors and measured performance showed these detectors had very low jitter allowing high time resolution.

Fiber-Based Quantum Key Distribution System

The figure above shows the configuration of the system. It uses two telecom fibers. One is the quantum channel for transmitting 850 nm photons with a mean photon number of 0.1. The other is the classical channel transmitting bi-directionally at 1510 and 1590 nm. Four silicon-based single photon detectors are used in the system. The NIST custom high-speed electronic printed circuit board handles the quantum and classical channels and the sifting protocol. The NIST reconciliation and privacy amplification protocols are currently implemented in software.

Shifted-key Rate vs. Distance The system generates 4 Mbit/s of sifted key over 1km of fiber, and 1 Mbit/s over 4km. From calculation it should be able to generate sifted key at 0.1 Mbit/s over 8 km of fiber.	Achievable performance of the NIST software Reconciliation and Privacy Amplification algorithms.
The next generation of high-speed electronics will provide faster QKD operation by using higher frequencies and incorporat8ng reconciliation and privacy amplification in hardware.

Surveillance Network As an example of an application for our high speed QKD system we are constructing a video surveillance network with three nodes (one Alice & two Bobs). Alice can alternatively view QKD secured real-time video signals from either the cameras at Bob1 or at Bob2, which are at two different locations.	The NIST secure QKD video surveillance application encrypts, transmits and decrypts web quality video continuously over the internet using a continuously generated real-time QKD secure key.


Future Plans

Enhancement of current system: Future plans include increasing the speed of the QKD system through improved optical subsystem and enhanced high speed electronics which will incorporate the reconciliation and privacy amplification algorithms. The new electronics would result in a compact portable infrastructure whose QKD performance is independent of the computer it’s installed in. Additional plans will investigate approaches to achieve longer distance QKD through both Polarization and Phase encoded systems at telecomm wavelengths.

Switched Network Quantum Key Distribution: Currently QKD is a point-to-point scheme between a specific pair of nodes and is not currently integrated into existing security protocols. To accelerate the growth of QKD, NIST will continue its research and development on protocols, performance measures and testing methods to extend QKD to a scalable, switched networked environment. Integrating QKD systems into standard networks is a complex endeavor. Our approach is to start with a Local Area Network with the intension of using existing network infrastructure and multiple QKD end-points.

Customers

QC Researchers

Collaborators

DARPA BBN, MagicQ Inc UMBC NIST PL/EEEL

Related Publications

Xiao Tang, Lijun Ma, Alan Mink, Anastase Nakassis, Hai Xu, Barry Hershman, Joshua Bienfang, David Su, Ronald F. Boisvert, Charles Clark, and Carl Williams, "Demonstration of an Active Quantum Key Distribution Network", Proc. SPIE Vol. 6305, 630506 (Aug. 29, 2006).
Lijun Ma, Hai Xu, and Xiao Tang, "Polarization recovery and auto-compensation in Quantum Key Distribution network", Proc. SPIE Vol. 6305, 630513 (Aug. 30, 2006).
D. J. Rogers, C. J. Bienfang, A. Mink, B. Hershman, A. Nakassis, X. Tang, L. Ma, D. H. Su, C. J. Williams, C. W. Clark, "Free space quantum cryptography in the H-alpha Fraunhofer window", Proc. SPIE Vol. 6304, 630417 (Sep. 1, 2006).
Hai Xu, Lijun Ma, Joshua C. Bienfang, and Xiao Tang, "Influence of Avalanche-Photodiode Dead Time on the Security of High-Speed Quantum-Key Distribution Systems", CLEO/QELS, Conference Technical Digest CD-ROM: JTuH3.pdf, Long Beach, CA, May 21-26, 2006.
Xiao Tang, Lijun Ma, Alan Mink, Tassos Nakassis, Hai Xu, Barry Hershman, Joshua C. Bienfang, David Su, Ronald F. Boisvert, Charles W. Clark, and Carl J. Williams, "Quantum Key Distribution System Operating at Sifted-key Rate Over 4 Mbit/s", Proceedings of SPIE, Vol. 6244, page 62440P-1-62440P-8 (April 2006).
Tassos Nakassis, J.C. Bienfang, P. Johnson, A. Mink, D. Rogers, X. Tang, and C. J. Williams, "Has Quantum Cryptography Been Proven Secure?", Proceedings of SPIE, Vol. 6244, page 62440I-1-62440I-9 (April 2006).
Alan Mink, Xiao Tang, Lijun Ma, Tassos Nakassis, Barry Hershman, Joshua C. Bienfang, David Su, Ron Boisvert, Charles W. Clark, and Carl J. Williams, "High Speed Quantum Key Distribution System Supports One-Time Pad Encryption of Real-Time Video", Proceedings of SPIE Vol. 6244, page 62440M-1-62440M-7 (April 2006).
Xiao Tang, Lijun Ma, Alan Mink, Tassos Nakassis, Hai Xu, Barry Hershman, Joshua C. Bienfang, David Su, Ronald F. Boisvert, Charles W. Clark, Carl J. Williams, "Experimental study of high speed polarization-coding quantum key distribution with sifted-key rates over Mbit/s", Optics Express, Vol. 14, Issue 6, pp. 2062-2070 (March 2006).
Publication list FY2005

Xiao Tang, Lijun Ma, Alan Mink, Anastase Nakassis, Barry Hershman, Joshua Bienfang, Ronald F. Boisvert, Charles Clark and Carl Williams, "High Speed Fiber-Based Quantum Key Distribution using Polarization Encoding," in Optics and Photonics 2005: Quantum Communications and Quantum Imaging III, Proceedings of SPIE Vol. 5893, Page 58931A-1-58931A-9 (August 2005).
Publication list FY2004

J. Bienfang, A. Gross, A. Mink, B. Hershman, A. Nakassis, X. Tang, R. Lu, D. Su, Charles Clark, Carl Williams, E. Hagley, Jesse Wen, "Quantum key distribution with 1.25 Gbps clock synchronization", Optics Express. Vol. 12 (9), 2011 (May 2004).


www.antd.nist.gov
Web site owner: The National Institute of Standards and Technology
	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: May, 2006 Date Created: May, 2001