Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.

September 28, 2006
12:30 PM

Danna Rosenberg,
P-21, Los Alamos National Labratory

Quantum Key Distribution with Decoy Levels

Abstract

Ideally, quantum key distribution (QKD) provides a method for two users to communicate with security guaranteed by the laws of quantum mechanics, but the security and reliability of practical QKD systems are closely tied to the properties of realistic sources and detectors. For example, the use of heavily attenuated laser sources makes most QKD systems vulnerable to photon-number-splitting attacks, and dark counts in the detectors limit the range of a QKD link. I will discuss recent experiments that used low-noise superconducting transition-edge sensors to extend the range of QKD and that utilized decoy states to remove the threat of photon number splitting attacks, enabling truly secure quantum key distribution over 107 km of optical fiber.