Security Evolves From Dinosaur Age

If the development of computers can be likened to evolution, today's machines would be dinosaurs, and the nascent quantum computers being developed in labs would be the small furry marsupials that eventually replaced the thunder lizards. As quantum computing advances in the next decade or so, it will render obsolete the traditional algorithm-based cryptography technology that secures Web transactions and electronic documents, because cracking such cryptography will be so easy. But as in evolution, scientists promise quantum cryptography will give back the security that quantum computing takes away.

In September, scientists at Los Alamos National Laboratory conducted an experiment that helped prove quantum cryptography could work as well in the real world as on paper. Richard J. Hughes, the lab's principal investigator of projects in quantum cryptography over optical fibers and for satellite communications, says the experiment was a success, though he can't give details until the results are reported in an upcoming scientific journal. Hughes' team was trying to beam quantum-encrypted information via very faint pulses of light through more than their previous best of 10 kilometers of open air. All Hughes would say is the latest experiment "went further than what we've reached previously."

The cryptography works through the polarization of light, though it still comes down to traditional ones and zeros. For instance, a ray of light polarized at angle A may be a "1" and another photon at a different angle would be a "0," and the sender and receiver of the signal could randomly shift their pattern to shake off any eavesdroppers.

Because Heisenberg's Uncertainly Principle states that the more precisely the position of a particle is determined, the less precisely the momentum is known, and vice versa, the quantum crypto-channel isn't measurable by outside observers, and any observation attempts will disturb the signal and hence reveal the presence of eavesdroppers.