But time and time again, the so-called "air gaps" between classified and public networks have been bridged, largely through the use of discs and removable drives.
The use of a polymer filling for the gaps instead of air lets the Singapore agency create a 3D, cavity-backed silicon antenna that measures just 0.06 by 0.04 inches, roughly the size of a seed on your hamburger bun, even as it increases the breakneck pace.
The thwarted attack, in which suspect Umar Farouk AbdulMutallab allegedly tried to ignite a bomb hidden in his underwear, has rattled air carriers and passengers, largely because it exposed gaps in a vast and expensive security net designed to keep terrorists off planes.