By Peter Weiss
Today’s most powerful methods for protecting secret communications may not remain secure tomorrow. That’s because they rely on the difficulty of gnarly calculations that may someday succumb to faster computers, scientists say. However, secrecy based on the inviolable laws of nature—if such protection proves technically feasible—will keep spies completely in the dark.
Researchers now present the first experimental evidence that laws of quantum mechanics could shield signals all the way from the ground to satellites in low orbits. This potential channel for totally secure communications may appeal to military and government agencies, banks, and other security-conscious organizations, says William T. Buttler of Los Alamos (N.M.) National Laboratory.