“The new theoretical research examines transmissions of
individual quantum states, such as sending a single
photon down a fiber-optic cable and reading off its
polarization on the far end. Rather than shipping the
lone photon down a clean and undisturbed line, the
researchers considered sending information down two
lines that contained too much static to transmit
anything reliably. When the lines were examined alone,
each noisy channel proved as useless as a dead telephone
jack. However, the researchers calculated that someone
on the far end of two noisy channels used together could
in fact extract actual information from the individually
worthless lines.” source...