Security at light speed

Researchers at the National Institute of Standards and Technology have tested a high-speed exchange of cryptographic keys using a stream of photons, the smallest pulses of light. Such transmission is secure from eavesdropping because tapping into a photon stream changes its physical properties. "Detecting a photon involves its destruction," a NIST official said.

NIST's quantum key distribution system sent a stream of photons 730 meters between two buildings at a rate of 1 megabit per second, which is 100 times faster than similar systems. New York-based MagiQ Technologies Inc. and Swiss firm ID Quantique have slower commercial offerings that use the quantum technology.